ATOMIZATION APPARATUS

INTRODUCTION

The invention relates to atomisation apparatus and is in particular concerned with supply of non-driving gas to an atomisation zone via conduits so configured as to optimise gas flow. The invention is also concerned with the provision of adjustments to flow of atomisation liquid whereby different application contexts, in particular different atomisation liquids, can be accommodated. In addition, the invention is concerned with construction of atomisation apparatus facilitating simple removal of nozzles e.g. for cleaning or replacement.

BACKGROUND

Gas and liquid flow passageways are commonly provided with a Venturi constriction in orderto atomise a liquid as a discontinuous phase in a continuous gas phase. Low pressure is generated at the constriction which can be used to draw liquid into a gas flow passing through the Venturi constriction.

As gas flows through the constriction, the gas molecules accelerate. The molecules must accelerate in the constricted region in order for the total flow rate to remain the same; in other words, because of the smaller cross-section of the constriction, the molecules must move faster in order for the numerical count of molecules passing through the Venturi to remain constant.

At a molecular level, gas molecules in a Venturi constriction are more likely to be traveling in the direction of flow. They are therefore less likely to collide with the passageway walls. When they do collide with the apparatus walls, they are more likely to do so with less force. Gas molecules are in constant motion at very high velocity, but in general at a speed in any particular direction which is very much slower. Where gas molecules travel in the direction of flow of gas stream, a greater proportion of their thermal energy is deployed in the same direction and a much smaller proportion deployed in random motion in

SUBSTITUTE SHEET (RULE 26) various directions. The effect of this is high-speed of molecular travel through a Venturi constriction. A Venturi is in effect a speed filter in that it selects high-speed molecules. It is recognised that the high-speed of travel of molecules through a Venturi constriction produces low pressure in the Venturi constriction and that this extends a finite distance downstream of the Venturi constriction outlet. As gas molecules exit a Venturi constriction, they reacquire their freedom to scatter and scatter in multiple directions therefore losing speed in terms of overall direction.

Apparatus based on inclusion of a Venturi constriction are well known for various applications.

PRIOR ART

EP 3 007 830 Bl discloses a Venturi-type mist device to be used in particular for the purposes of disinfection or decontamination in an enclosed space. The device disclosed addresses the problem of cleaning in order to remove residual chemicals from the device. The document points out that prior devices have a number of disadvantages in this respect, in particular the disadvantage that to run a cleaning liquid through the device requires the cleaning liquid together with entrained chemicals to be sprayed from nozzles of the device either into the environment of the cleaning location space or into a specially prepared space. The document proposes as a solution to this problem an arrangement in which a nozzle head is displaceable, by use of a motorised mechanism, upon a linear path between retracted and raised positions. In the raised position, a nozzle outlet array directs atomised process liquid radially of the nozzle head into the environment to be decontaminated, whilst in the retracted position, the nozzle outlet array is directed into a drain chamber defined between the nozzle head and a nozzle cover. In the EP 3 007 830 Bl apparatus, process liquid enters the nozzle lumen exclusively via the Venturi and the document does not disclose any structure in which a further gas stream by-passes the Venturi constriction to enter the nozzle lumen separately and no particular details are given for the profile of the nozzle lumen, or any other passageway or pathway, either in cross-sectional terms or longitudinally. The atomisation of the disinfectant process liquid disclosed is achieved using primary and secondary break-up mechanisms. The primary

SUBSTITUTE SHEET (RULE 26) mechanism is the high shear force applied to the disinfectant by the compressed air, which forms ligaments at the boundary surface of the liquid disinfectant. These ligaments are stripped from the surface and atomised into droplets. Two secondary break-up mechanisms further atomise the droplets produced by the primary break-up.

CN 1048815815A discloses a Venturi apparatus which has two operation modes. In the first, water is propelled from a nozzle outlet fed from two internal passageways. In the second operation mode, reduction of the pressure in one passageway leads to its closure and the injection into the other passageway, at the locus of a Venturi constriction, of detergent in order to feed the nozzle with an aqueous detergent solution which is propelled from the nozzle outlet as a spray. The document does not disclose any particular configuration for either of the two passageways referred to.

US 2014/0076996 Al discloses a spray gun and portable mist-generating apparatus particularly suitable for rapid deployment and operation in decontamination, disinfection and fire suppression locations within buildings and other urban environments. The apparatus proposed in this document addresses a problem experienced with previous devices in which either mechanical atomisation of a process liquid through a nozzle produces a mist composed of relatively large droplets which fall to ground relatively quickly, limiting the effectiveness of the apparatus and also placing the operator of the apparatus at some risk, or else twin-fluid atomisation is used but with the disadvantage that the then available atomisers is of this type have fixed flow rates for the driving fluid and the process fluid. In the apparatus proposed in US 2014/0076996 Al, a main part of the driving gas is transmitted to a central passage 182, shown in Figures 14 and 15 of the drawings, of a nozzle 184-182-188 from a nozzle inlet 184 and proceeds to a nozzle outlet 188 via an intermediate narrow throat 186 of the nozzle. Another driving gas portion is received by driving fluid gallery and bypass channels 183. A process fluid outlet 190 opens into nozzle central passage 182 at or downstream of the nozzle throat 186. Unlike the construction disclosed in EP 3 007 830 Bl, the nozzle 184-182-188 is fixed in position in US 2014/0076996 Al. As shown in the drawings of the above document, the apparatus is adapted so that process fluid is introduced into central passage 182 in the opposing direction to the flow direction of driving fluid through that central passage. Bypass

SUBSTITUTE SHEET (RULE 26) channels 183 output at outlet 187 in communication with process fluid supply whereby a small amount of process fluid participates in a pre-atomisation process prior to the process fluid undergoing full atomisation in the nozzle. A flow adjustment device is used to control the flow of both driving fluid and process fluid. This flow adjustment device comprises a set of differently sized alternately selectable orifices regulating driving fluid flow and a separate set of differently sized alternately selectable orifices regulating process fluid flow in order to enable the overall apparatus to be operated at different respective flow rates for each fluid. US 2014/0076996 Al discloses no particular details for the bypass channels 183 responsible for driving gas bypass flow.

US 2019/035 0187 Al discloses an agricultural sprayer which employs a configurable nozzle to change the characteristics of the spray generated. The nozzle has various disclosed forms. In one form, a pair of opposed orifice plates are respectively displaceable to change nozzle outlet profile through operation of respective orifice actuators by threaded transmission elements engaging in threaded lugs coupled to respective orifice plates. Rotation of the threaded transmission elements is experienced as linear displacement of the respective orifice plates through these lugs to open and close the separation between the orifice plates, so changing the nozzle outlet orifice profile and the outlet characteristics of the spray generated from the nozzle. Liquid is fed to the nozzle along a main sprayer passageway, which is not described in terms of its configuration, which effectively forms part of a manifold supplying plural nozzle assemblies. As part of such manifold, ports are provided for injecting controlled amounts of an additive into the liquid stream transmitted to the nozzle. In another embodiment of the proposal in US 2019/035 0187 Al, a liquid-receiving passage terminates in a conical portion which leads liquid flow to a flow constriction, where the nozzle terminates in an outlet. Immediately upstream of the outlet and within the conical section, an orifice plate of non-planar form defines a port for communication with the nozzle outlet. The orifice plate is arranged for rotation, in response to cooperation of a threaded transmission element with a threaded lug of the orifice plate, to move its port in and out of alignment with the nozzle outlet. This alters the outlet profile experienced by the liquid output generated and influences spray pattern and droplet size. A blender is coupled to the liquid flow passageway upstream of the conical section to enable mixing of the liquid flow with another fluid such

SUBSTITUTE SHEET (RULE 26) as air. The blending system comprises fluid inputs controlled by, for example, needles of choke elements operated by respective actuators which displace the needles to constrict fluid flow into the liquid flow passageway. There is no disclosure of any particular configuration for any gas pathway or passageway.

INTRODUCTION TO ASPECT 1

In this first aspect, the invention is concerned with a construction in which, in addition to a driving first gas stream transmitted to the gas flow constriction in a gas transmission first pathway, a bypass second gas transmission means comprising plural gas transmission further pathways (although a single pathway may also be used) bypasses the constriction to meet with Venturi output gas in a mixing zone downstream of the constriction. The gas transmission further pathways have a particular cross-section and, preferably, also a particular length profile, which enables a smooth and efficient gas transmission leading to improved mixing, a well-projected plume, desirably small liquid phase droplet sizes and a narrow droplet size distribution.

SUMMARY OF ASPECT 1

The invention in its several sub- aspects provides an atomisation apparatus, a constricted gas flow module for such an apparatus, a gas transfer device and a gas transfer method.

Constricted gas flow in the atomisation apparatus, gas transfer device or gas transfer method provided by the invention, will generally be provided by means of a Venturi constriction but, in its broadest sense, the invention contemplates other forms of gas flow constriction (in which gas is accelerated to form an accelerated gas stream and a zone of reduced pressure) which may not be considered to be Venturi constrictions. By the expression "constricted gas flow assembly" the applicant intends to refer to any constricted gas flow device, module, body or assembly without, for example, limitation to whether it was made by a process of assembly or made as a single part

SUBSTITUTE SHEET (RULE 26) In its simplest and most fundamental form, the invention provides a gas transfer device which defines a gas pathway (e.g. a conduit), extending between an inlet and an outlet spaced apart from said inlet, for transmission of a stream of said gas from a location proximate said inlet to a gas-receiving location proximate said outlet, said pathway having an obround or oval cross-sectional shape of the same orientation throughout at least a downstream length portion of the pathway length extending in an upstream direction from said outlet. Preferably, there will be plural gas pathways as defined above. There may be in the device one or more gas pathways which are not as defined above but in general it is preferred that this will not be the case, it being preferred that the gas transfer device should comprise plural gas pathways all of which have an obround or oval cross- sectional shape, and particularly preferred that all said plural pathways be identical or substantially so.

The downstream length portion of the pathway length conveniently extends to at least 40% of the displacement between the pathway inlet and outlet, and preferably extends to at least 50% of the displacement between the pathway inlet and outlet, for example, to at least 75% of the displacement between the pathway inlet and outlet.

In the most preferred embodiments, the downstream length portion of the pathway length occupies the entire or substantially the entire displacement between the pathway inlet and outlet.

It is significantly preferred that the cross-sectional area of said pathway downstream length portion should diminish in a downstream direction over at least a downstream subportion of said pathway downstream length portion extending in an upstream direction from said outlet. For example, the downstream sub-portion of said pathway downstream length portion may extend in an upstream direction from said outlet and have an extent along the length of the pathway equal to at least 75% of that of said pathway downstream length portion. Preferably, the downstream sub-portion of said pathway downstream length portion extends in an upstream direction from said outlet and has an extent along the length of the pathway equal to all or substantially all of the extent of said pathway downstream length portion.

SUBSTITUTE SHEET (RULE 26) In embodiments where the cross-sectional area of the pathway downstream length portion diminishes linearly in a downstream direction as described above, the cross- sectional area of said pathway downstream length portion reduces such that one or both of the following dimensions of the obround or oval diminish linearly in a downstream direction throughout the length of said downstream sub-portion, namely: (i) the length of a line joining the centres of the end cap arcs and passing at all points midway between the sides of the obround or oval which join the arcs and (ii) the length of a line which dissects the previously mentioned line and extends between the mid-points of the sides of the obround or oval.

Returning to the preferred feature that there will be plural gas pathways, it is not necessary that all of such a plurality have the obround/oval shape for their cross-section is as described earlier; one or more of those pathways will be so defined, with the others possibly having a different form. However, it is preferred that most, and preferably all, of gas pathways have an obround or oval cross-sectional shape of the same orientation throughout at least a downstream length portion of the pathway length extending in an upstream direction from said outlet.

It is, however, more generally preferred that all of plural gas pathways are identical to one another. Where this is not so, the complement of gas pathways may be diverse, with one or more tapered (i.e. configured with diminishing cross-sectional area as described above) in a first manner of tapering and others in a different manner of tapering or in a range of different manners. Equally, plural gas pathways might include pathways differing with respect to the specific obround/oval shape; for example, plural gas pathways might include pathways which are obround in one or more cases and either oval or differently obround in one or more other cases (or some combination of such shapes).

Each gas pathway is preferably linear from its inlet orifice to its outlet orifice and the central longitudinal axis of each said gas pathway is preferably parallel to the central longitudinal axes of all the other said gas pathways.

SUBSTITUTE SHEET (RULE 26) Plural gas pathways will generally be comprised in a gas pathway array of said gas pathways, the pathways preferably arrayed in said array in equally spaced apart relationship with respect to one another.

Conveniently, plural gas pathways are arranged so that their central longitudinal axes follow the surface of a virtual parallel-sided cylinder of circular or rectangular base and are preferably aligned with and parallel to the central longitudinal axis of the virtual cylinder, the central longitudinal axes of said gas pathways preferably also feeding parallel to each other.

In a preferred embodiment, the gas pathways originate in inlet orifices at a gas inlet gallery of the device comprising a gas inlet orifice respective to each said gas pathway. It is also preferred for all said gas pathways to terminate in outlet orifices at a gas outlet gallery of the device comprising a gas outlet orifice respective to each said gas pathway.

In an especially preferred embodiment, all said gas pathways originate in inlet orifices at a gas inlet gallery of the device comprising a gas inlet orifice respective to each said gas pathways and also terminate in outlet orifices at a gas outlet gallery of the device comprising a gas outlet orifice respective to each said gas pathway, the gas inlet gallery inlet orifices and the gas outlet gallery outlet orifices being preferably arrayed in respective circular arrays.

The gas transfer device of the invention may, of course, include one or more features of the other aspects of the invention described in the following description.

The sub- aspect of the invention described above is allied to a further aspect, namely a gas transfer method which method comprises passing a stream of gas along a gas pathway extending between a location proximate a pathway inlet to a gas-receiving location proximate a pathway outlet, said pathway having an obround or oval cross-sectional shape of the same orientation throughout at least a downstream length portion of the pathway length extending in an upstream direction from said outlet. A liquid stream may

SUBSTITUTE SHEET (RULE 26) conveniently be supplied to the gas-receiving location whereby said gas and liquid streams combine.

The gas transfer device is obviously capable of deployment to practice the gas transfer method described above.

Turning now to those further sub- aspects invention, the invention provides a constricted fluid flow transmission device for use in an atomisation apparatus to deliver driving gas and non-driving gas separately to different output locations of the device for deployment by the atomisation apparatus as a continuous phase in which to atomise a liquid as a discontinuous phase, said device comprising driving gas transmission means defining a gas transmission first pathway for receiving a supply of driving gas and transmitting it as a driving gas stream through a gas flow constriction (for example, a Venturi constriction) provided in said gas transmission first pathway (for example, at or proximate the downstream extremity of the gas transmission first pathway) whereby said driving gas stream is accelerated by said constriction and output at an accelerated driving gas output orifice of the device at a first device output location, said device further comprising further gas transmission means for non-driving gas, defining one or more (and preferably plural) gas transmission further pathways for receiving a supply of non-driving gas and transmitting it as one or more non-driving gas further gas streams, bypassing said constriction, each to an outlet orifice of a respective gas transmission further pathway at non-driving gas output means of the apparatus at a second device output location, at least one of said one or more gas transmission further pathways having an obround or oval cross-sectional shape throughout at least a downstream length portion comprised in the gas transmission further pathway and extending in an upstream direction from said outlet orifice of the gas transmission further pathway, said obround or oval cross-section shape having the same orientation throughout that downstream length portion.

It will be appreciated that atomisation is a process may continue in the upstream end portion of the nozzle lumen, where (as explained in detail hereinafter in the section "Liquid Zone 900" in the context of a specific embodiment), supersonic mixing velocity will usually continue to prevail.

SUBSTITUTE SHEET (RULE 26) The invention further provides an atomisation apparatus comprising a constricted fluid flow transmission device as defined above, a nozzle having an inlet orifice and an outlet orifice connected by an atomised mixture passageway (e.g. a lumen for transmission of an atomised mixture) extending between them for transmission of atomised mixture from said inlet orifice to said outlet orifice, an atomisation chamber disposed (eg between said accelerated driving gas output orifice of said device and the inlet orifice of said nozzle and in communication with both) to receive said accelerated driving gas transmitted to said device output first location and to output atomised mixture to or along the nozzle, and a fluid passageway having an inlet for receiving said non-driving gas from said non-driving gas output means and transmitting it from said device output second location to said atomisation chamber preferably via a pre-mixing zone, the apparatus further including atomisation liquid introduction means for introducing an atomisation liquid into the accelerated gas stream for atomisation, such introduction taking place usually in the atomisation chamber or upstream thereof.

Preferably, the fluid passageway of the atomisation apparatus is disposed to input to, and receive liquid-containing outputs from, a premixing chamber. Such premixing chamber may have, and may be identifiable as having, a different form to the (rest of the) fluid passageway (for example, in terms of its configuration and/or its cross-sectional size) or as having a different orientation (for example, it may be oriented so as to form a fluidically connecting bridge between a gas transmission further pathway and the fluid passageway e.g. when these latter two elements of the apparatus are oriented to transmit fluid streams in different directions.

It is generally always preferred for the atomisation liquid introduction means to introduce the atomisation liquid into a premixing zone, e.g. forming part of the fluid passageway, where it pre-mixes with non-driving gas therein for introduction into the accelerated driving gas as a premixture of atomisation liquid and non-driving gas. However, it may also be convenient to introduce atomisation liquid into the accelerated driving gas stream, conveniently into the atomisation chamber, not so mixed, with the non-driving gas, either premixed with atomisation liquid or not so mixed, conveniently separately introduced into the accelerated driving gas stream (conveniently into the atomisation chamber).

SUBSTITUTE SHEET (RULE 26) Thus, in summary, the invention includes within its scope apparatus as described above and comprising (i) a fluid passageway and (ii) atomisation liquid introduction means, the atomisation liquid introduction means:

A. feeding atomisation liquid into the fluid passageway, the fluid passageway outputting atomisation liquid to the accelerated gas stream as a combination with non-driving gas: a. into the atomisation chamber, or b. otherwise into the accelerated gas stream (e.g. upstream of the atomisation chamber),

B. feeding atomisation liquid at an input into a premixing chamber fed with nondrivinggas, the premixing chamber feeding a premixture of atomisation liquid with non-driving gas: a. from an output of the premixing chamber to the fluid passageway, or b. from an output of the premixing chamber into the accelerated driving gas: i. in the atomisation chamber, or ii. otherwise into the accelerated gas stream

The pathway downstream length portion conveniently extends in an upstream direction from said outlet orifice for a distance of at least 40%, most conveniently at least 50%, for example, at least 75%, of the total length of its gas transmission further pathway.

Preferably, the pathway downstream length portion occupies the entire or substantially the entire length of its gas transmission further pathway.

It is a preferred feature of the constricted fluid flow transmission device of the invention that the cross-sectional area of said pathway downstream length portion should diminish, in the case of one or more of said gas transmission further pathways, linearly in a downstream direction over at least a downstream sub-portion of said pathway downstream length portion extending in an upstream direction from said outlet orifice of the gas transmission further pathway. The downstream sub-portion of said pathway downstream length portion preferably extends in an upstream direction from said outlet

SUBSTITUTE SHEET (RULE 26) orifice and has an extent along the length of the pathway equal to at least 75% of that of said pathway downstream length portion. Advantageously, the downstream sub-portion of said pathway downstream length portion extends in an upstream direction from said outlet orifice and has an extent along the length of said pathway downstream length portion equal to all or substantially all of the extent of said pathway downstream length portion.

Conveniently, the downstream length portion of at least one said gas transmission further pathway has a cross-sectional area which diminishes linearly by an amount of from 25% to 50% (e.g. 30% to 40%) in a downstream direction over at least a downstream subportion of said downstream length portion of said gas transmission further pathway, said sub-portion extending in an upstream direction from said outlet orifice of said gas transmission further pathway.

Where the cross-sectional area of said downstream pathway sub-portion reduces as just described, it may conveniently reduce such that one or both of the following dimensions of the obround or oval diminish linearly in a downstream direction throughout the length of said downstream sub-portion, namely: (i) the length of a line joining the centres of the end cap arcs and passing at all points midway between the sides of the obround or oval which join those arcs and (ii) the length of a line which dissects the previously mentioned line and extends between the mid-points of the sides of the obround or oval.

A variety of obround/oval shapes can be used in the gas transmission further pathway(s). For example, the shape may be one in which the length of a straight line joining the centres of the end cap arcs of the obround or oval and passing at all points midway between the sides of the obround or oval which join the arcs is from 1.05X to 1.25X (e.g. 1.10X to 1.20X and preferably about 1.15X) the length of a straight line which (i) dissects the previously mentioned straight line joining the centres of the end cap arcs and (ii) extends between the mid-points of the sides of the obround or oval.

Conveniently, each said gas transmission further pathway is linear from its inlet orifice to its outlet orifice and the central longitudinal axis of each said gas transmission further

SUBSTITUTE SHEET (RULE 26) pathway is parallel to the central longitudinal axes of all the other said gas transmission further pathways.

It is highly preferred that the constricted fluid flow transmission device of the invention be one in which the further gas transmission means (for non-driving gas) defines plural gas transmission further pathways for transmitting said non-driving bypass gas in respective further gas streams from respective inlet orifices to respective outlet orifices of respective said gas transmission further pathways.

In such preferred embodiment of the constricted fluid flow transmission device, the plural gas transmission further pathways are preferably comprised in a gas transmission further pathway array of said plural gas transmission further pathways. Conveniently, the plural gas transmission further pathways are arrayed in said gas transmission further pathway array in equally spaced apart relationship with respect to one another.

It is preferred that the plural gas transmission further pathways are arranged about, and so that there axes are parallel to, the surface of a virtual parallel-sided cylinder of circular or rectangular base.

For example, the gas transmission first pathway may be arranged to transmit said first gas stream on a first gas stream flow path to the constriction, which flow path is coaxial with the central axis of said virtual cylinder. The virtual cylinder is conveniently a right cylinder of circular cross-section and, at each point of cross-section cross-sectioning all of said gas transmission further pathways through their said respective pathway downstream length portions, each obround or oval is conveniently intersected by a respective radius which (i) extends from the cylinder axis to the midpoint of the longitudinal axis of the obround or oval connecting the end caps thereof, (ii) is of the same length between those axes as all the others and (iii) intersects the obround or oval longitudinal axis at a right angle. Preferably, at each said point of array cross-section, the longitudinal axes of the obrounds or ovals in aggregate form a discontinuous virtual line the interruptions in which are of equal magnitude to one another and represent in each instance the spacing between one said gas transmission further pathway and a next adjacent said gas transmission further

SUBSTITUTE SHEET (RULE 26) pathway of the plurality thereof at that common point of cross-section, each said gas transmission further pathway being e.g. identical in configuration to all the other said gas transmission further pathways.

In preferred constricted fluid flow transmission devices, all said gas transmission further pathways forming part of said plurality of said gas transmission further pathways originate in inlet orifices at a gas inlet gallery of the device comprising a gas inlet orifice respective to each of said gas transmission further pathways. It is also preferred that all said gas transmission further pathways forming part of said plurality of said gas transmission further pathways terminate in outlet orifices at a gas outlet gallery of the device comprising a gas outlet orifice respective to each of said gas transmission further pathways.

Most preferred therefore are constricted fluid flow transmission devices in which all said gas transmission further pathways originate in inlet orifices at a gas inlet gallery of the device comprising a gas inlet orifice respective to each of said gas transmission further pathways and terminate in outlet orifices at a gas outlet gallery of the device comprising a gas outlet orifice respective to each of said gas transmission further pathways and wherein the gas inlet gallery inlet orifices and the gas outlet gallery outlet orifices are all arrayed in respective circular arrays.

Conveniently, the first gas transmission means defines, as at least part of said gas transmission first pathway, a gas convergence zone tapering in cross-section from a convergence zone upstream mouth for receiving compressed gas supplied to the apparatus to a minimum cross-section downstream thereof at the mouth of the constriction. The ratio between the convergence zone cross-sectional area at its mouth and its cross-sectional area at the mouth of the constriction is preferably from 2.75:1 to 2.60:1, preferably from 2.7:1 - 2.65:1 (eg about 2.67:1).

The convergence zone referred to is preferably defined by one or more device walls enclosing a frusto-conical void which opens at its upstream extremity represented by the base of the frusto-cone in said convergence zone mouth and which opens at its the downstream extremity to said constriction. Preferably, all of plural gas transmission

SUBSTITUTE SHEET (RULE 26) further pathways originate in a gas inlet gallery comprising an array of gas inlet orifices each one thereof respective to one of said gas transmission further pathways and said array circumscribing the gas convergence zone at a location proximate its upstream mouth.

The convergence zone mouth may form a sole inlet to the convergence zone.

The non-driving gas further gas transmission means preferably provides a total transmission further pathway inlet cross-sectional area which is equal to that of the convergence zone at its minimum cross-sectional area, individual gas transmission further pathway inlet cross-sectional area in the case of each said non-driving gas transmission further pathway being measured at the most upstream point at which that gas transmission further pathway has a cross-section plane intersecting all of its sides and intersecting the gas transmission further pathway longitudinal axis orthogonally.

The output orifice for the accelerated driving gas from the Venturi or other constriction conveniently opens into a downstream chamber of the device which is downstream of said constriction and preferably increases in cross-sectional area in a downstream direction from a minimum cross-sectional area at the constriction exit to a maximum at a downstream mouth of said chamber. The chamber is conveniently defined by one or more chamber walls which enclose a frusto-conical void which opens at its upstream extremity to said constriction and which is open at its downstream extremity represented by the base of the frusto-cone. Plural said gas transmission further pathways preferably all terminate in a gas outlet gallery comprising an array of gas outlet orifices each one thereof respective to one of said gas transmission further pathways and said array circumscribing said chamber at a location proximate its downstream mouth.

The constricted fluid flow transmission device according to the presently described aspect of the invention is preferably one in which a linear reduction in cross-sectional area is suffered, in a downstream direction, of at least one of said gas transmission further pathways, in at least a downstream sub-portion of said pathway downstream length portion, and takes the form of a reduction in one or both of width and length (preferably

SUBSTITUTE SHEET (RULE 26) both) of the obround or oval, with said width reduction preferably being the same in magnitude in the case of each said gas transmission further pathway and said length reduction being the same in magnitude in the case of each said gas transmission further pathway.

Conveniently, the ratio between the cross-sectional area of the outlet orifice, in the case of one or more said gas transmission further pathways and that of the corresponding gas transmission further pathway inlet orifice is from 1 : 1.5 to 1 : 2.0.

As regards materials and gas transmission further pathway formation: o The further gas transmission means conveniently comprises a body of stainless steel in which said gas transmission further pathways are formed. o The further gas transmission means conveniently comprises a body of metallic material in which said gas transmission further pathways are formed by spark erosion. o At least the gas-contacting surfaces of the means defining said gas transmission first pathway are made of stainless steel. o Most preferably, the device as a whole is made of stainless steel surfaces, with cost, however, been a factor.

A gas inlet zone may be provided for receiving compressed gas supplied to the apparatus, said gas inlet zone opening to said first gas transmission means and to said further gas transmission means for introduction of said compressed gas into said gas transmission first pathway and into said further gas transmission means.

The gas inlet zone may be defined by an open-sided chamber through whose open sides gas supplied to said gas inlet zone can enter said chamber.

SUBSTITUTE SHEET (RULE 26) The gas inlet zone is, for example, defined at its upstream extremity by a wall member having a concave internally-facing surface.

According to the invention, in a further sub-aspect, there is provided an atomisation apparatus for atomising an atomisation liquid as a discontinuous phase and for discharging atomised liquid and gas as a plume comprises , the apparatus comprising: - i. a constricted gas flow assembly comprising a body provided with first fluid transmission means comprised of a gas transmission first pathway (e.g. a conduit) for transmission in a first gas stream of gas supplied to the apparatus and having a flow constriction disposed in said gas transmission first pathway for receiving said first gas stream therethrough with increased velocity as a converged driving gas stream; ii. atomisation liquid supply means in the form of one or more fluid pathways provided in the apparatus for supplying to a pre-mixing region of the apparatus a stream of atomisation liquid supplied to the apparatus; iii. an atomisation region or chamber disposed to receive said driving gas stream; iv. further fluid transmission means for transmission of materials for atomisation to said atomisation region or chamber, said further fluid transmission means comprising the first and second further apparatus parts defined below:

(a) a first apparatus part which comprises plural gas transmission further pathways (or at least one such further pathway) provided in the apparatus (and preferably in the body of which apparatus part said constricted gas flow assembly is comprised) for transmission, in respective further gas streams to said second apparatus part of gas supplied to the apparatus, said further gas stream bypassing said flow constriction, and

SUBSTITUTE SHEET (RULE 26) (b) a second apparatus part which comprises said pre-mixing region and is disposed to receive, for mixing together in said premixing region to form a pre-mixture, said bypass gas and liquid of said liquid stream received from said atomisation liquid supply means and for transmitting said pre-mixture to said atomisation region or chamber for atomisation of the liquid thereof in a continuous gas phase; and v. a nozzle for receiving through an inlet orifice thereof admixed gas and atomised liquid from the atomisation region or chamber and having an outlet orifice from which to discharge said plume; characterized in that at least one said gas transmission further pathways has an obround or oval cross-sectional shape throughout at least a downstream length portion thereof extending in an upstream direction from an outlet orifice thereof through which bypass gas is delivered to said pre-mixing region, said obround or oval shape having the same orientation throughout the so-shaped gas transmission further pathway length portion.

Of course, as mentioned previously, atomisation may continue in the most upstream end portion of the nozzle lumen.

The premixture is preferably introduced into the increased velocity driving gas stream, at least tangentially of that gas stream (for example, perpendicularly to the direction of flow of that stream or, preferably, in a direction which opposes the direction of flow of that stream).

In connection with the constricted fluid transmission device provided by the invention, the downstream length portion of at least one said gas transmission further pathway conveniently extends in an upstream direction from its outlet orifice for a distance equal to at least 40% of the total length of that gas transmission further pathway. This and the narrower ranges of downstream length portion extents mentioned earlier in connection

SUBSTITUTE SHEET (RULE 26) with that device are, of course, applicable to the apparatus presently being described, as is the most preferred extent mentioned in connection with the constricted flow device.

As in the case of the constricted fluid flow transmission device, a preferred atomization apparatus is one in which according to the invention the cross-sectional area of said pathway downstream length portion diminishes, in the case of one or more of said gas transmission further pathways, linearly in a downstream direction over at least a downstream sub-portion of said pathway downstream length portion extending in an upstream direction from said outlet orifice of said gas transmission further pathway. The preferred extents of the downstream sub-portion mentioned in the context of the constricted fluid flow transmission device of the invention are also, of course, preferred in the case of the atomisation apparatus presently being described.

Similarly, the amount of cross-sectional area reduction of from 25% to 50% exemplified earlier in the context of the constricted fluid flow transmission device can be cited as an exemplification of what might be the amount of cross-section reduction of the downstream sub-portion cross-section, as indeed is the 30 to 40% reduction previously given in the constricted fluid flow transmission device context.

As in the constricted fluid flow transmission device context, the atomization apparatus is preferably one where the cross-sectional area of the pathway sub-portion reduces such that one or both of the following dimensions of the obround or oval diminish linearly in a downstream direction throughout the length of said downstream sub-portion, namely: (i) the length of a straight line joining the centres of the end cap arcs and passing at all points midway between the sides of the obround or oval which join the arcs and (ii) the length of a straight line which dissects the previously mentioned straight line joining the centres of the end cap arcs and which extends between the mid-points of the sides of the obround or oval.

The length of the straight line (i) is conveniently from 1.05X to 1.25X, preferably from 1.10X to 1.20X (especially, about 1.15X) the length of the straight line (ii), reflecting the earlier description of the constricted fluid flow transmission device.

SUBSTITUTE SHEET (RULE 26) More generally, a linear reduction in cross-sectional area may be suffered, in a downstream direction, of at least one of said gas transmission further pathways, in at least a downstream sub-portion of said pathway downstream length portion, and may take the form of a reduction in one or both width and length of the obround or oval, with said width reduction preferably being the same in magnitude in the case of each such gas transmission further pathway and said length reduction preferably being the same in magnitude in the case of each such gas transmission further pathway.

Referring further to the subject of gas transmission further pathway tapering, the preferred ratio between the cross-sectional area of the outlet orifice, in the case of one or more said gas transmission further pathways, and that of a corresponding gas transmission further pathway inlet orifice is from 1 : 1.5 to 1 : 2.0.

Each gas transmission further pathway is generally linear over its length and preferably the central longitudinal axis of each said gas transmission further pathway is parallel to the central longitudinal axes of all the other said gas transmission further pathways.

An atomization apparatus in which plural gas transmission further pathways are comprised in a gas transmission further pathway array are preferred arrangements, especially when those pathways are arrayed in equally spaced apart relationship with respect to one another.

Plural gas transmission further pathways may be arranged so that the central longitudinal axis of each said gas transmission further pathway is parallel to the surface of a virtual parallel-sided cylinder of circular or rectangular base, the first gas stream flow path preferably coaxial with the central longitudinal axis of said virtual cylinder. The virtual cylinder is most conveniently a right cylinder of circular cross-section in this case and, at each point of array cross-section cross-sectioning all of said gas transmission further pathways through their said respective downstream length portions, each obround or oval is intersected by a respective radius which (i) extends from the cylinder axis to the midpoint of the longitudinal axis of the obround or oval connecting the end caps thereof,

SUBSTITUTE SHEET (RULE 26) (ii) is of the same length between those axes as all the others and (iii) intersects the obround or oval longitudinal axis at a right angle.

With all said gas transmission further pathways provided with an obround or oval cross- sectional shape of the same orientation throughout at least the downstream length portion , it is preferred that, at each said point of array cross-section, the longitudinal axes of the obrounds or ovals in aggregate form a discontinuous virtual line the interruptions in which are of equal magnitude to one another and represent in each instance the spacing between one said gas transmission further pathway and a next adjacent said gas transmission further pathway of the array at that common point of cross-section, each said gas transmission further pathway preferably being identical in configuration to all the other said gas transmission further pathways.

All the gas transmission further pathways preferably originate in inlet orifices at a gas inlet gallery of the device comprising a gas inlet orifice respective to each of said gas transmission further pathways and preferably terminate in outlet orifices at a gas outlet gallery of the apparatus comprising a gas outlet orifice respective to each of said gas transmission further pathways and wherein the gas inlet gallery inlet orifices and the gas outlet gallery outlet orifices are all preferably arrayed in respective circular arrays.

The first fluid transmission means preferably defines, as at least part of said gas transmission first pathway, a gas convergence zone tapering in cross-section from a convergence zone upstream mouth for receiving compressed gas supplied to the apparatus to a minimum cross-section downstream thereof at the mouth of the constriction, the ratio between the convergence zone cross-sectional area at its mouth and its cross-sectional area at the mouth of the constriction conveniently being from 2.75:1 - 2.60:1, preferably from 2.75:1 - 2.60:1, and more preferably from 2.7:1 - 2.65:1 (eg about 2.67:1). The convergence zone is preferably defined by one or more atomisation apparatus walls enclosing a frusto-conical void which opens at its upstream extremity represented by the base of the frusto-cone in said convergence zone mouth and which opens at its the downstream extremity to said constriction.

SUBSTITUTE SHEET (RULE 26) Preferably, all of said gas transmission further pathways originate in a gas inlet gallery comprising an array of gas inlet orifices each one thereof respective to one of said gas transmission further pathways, with said array preferably circumscribing the gas convergence zone at a location proximate its upstream mouth.

Plural gas transmission further pathways preferably have together in aggregate an inlet cross-sectional area which is equal to that of the convergence zone at its narrowest, the individual gas transmission further pathway inlet cross-sectional area in the case of each said plural gas transmission further pathway being measured at the most upstream point at which said plural gas transmission further pathway has a cross-section plane intersecting all of its sides and intersecting the gas transmission further pathway longitudinal axis orthogonally.

In a particular embodiment of the atomization apparatus, a nozzle forms part of the apparatus and has a surface which together with a further apparatus surface defines a space therebetween which separates them and forms said second apparatus part (see iv (b) above) of said further fluid transmission means, both said surfaces being of frusto- conical form with the further apparatus surface defining a frusto-conical chamber in which the part of the nozzle which presents its said frusto-conical surface is received to form said space, said frusto-conical chamber increasing in cross-sectional area in a downstream direction from a minimum cross-sectional area at an end open to receive from said atomisation region gas admixed with atomised liquid to a maximum at a downstream chamber mouth.

The frusto-conical chamber is preferably defined by one or more chamber walls which enclose a frusto-conical void which opens at its upstream extremity to said constriction and which is open at its downstream extremity represented by the base of the frusto-cone to said pre-mixing region.

The gas transmission further pathways in the above arrangement conveniently all terminate in a gas outlet gallery comprising an array of gas outlet orifices, each one

SUBSTITUTE SHEET (RULE 26) thereof respective to one of said gas transmission further pathways, and said array circumscribes said chamber at a location proximate its downstream mouth.

Atomisation apparatus are preferred in which the gas transmission further pathways are each defined in and by a body of the apparatus which also preferably defines the constriction and which is separable from the rest of the apparatus. However, the gas transmission further pathways, more generally, may be formed in the body of an apparatus element or between two conjoined apparatus elements which come together to define the pathway as a region of materials removal or omission in one or both of said conjoined apparatus elements; for example, the pathway may be a channel, in one element or the other, which is closed by the other element to form a conduit or, alternatively, a conduit may be formed between two elements each of which is formed with part of the cross-section of the conduit so that a conduit in whole can be formed by the marriage of the two elements together in such a manner that the two-part cross sections of the conduit become integrated.

The atomisation apparatus conveniently includes a nozzle assembly which has a collar perforated by one or a plurality of liquid transmission pathways connecting a chamber for atomisation liquid, disposed in the apparatus on the downstream side of the collar (reading from the flow direction of said driving gas stream), with said pre-mixing region of the apparatus disposed on the upstream side of the collar (again reading from the flow direction of said driving gas stream).

Stainless steel may be used in the apparatus as described in connection with the constricted fluid flow transmission device of the invention.

At least the fluid-contacting surfaces of said second apparatus part preferably are made of stainless steel.

A gas inlet zone is conveniently provided for receiving compressed gas supplied to the apparatus, said gas inlet zone opening to said first fluid transmission means and to said further fluid transmission means for introduction of said compressed gas into said gas

SUBSTITUTE SHEET (RULE 26) transmission first pathway and into said plural gas transmission further pathway(s). The gas inlet zone is conveniently defined by an open-sided chamber through whose open sides gas supplied to said gas inlet zone can enter said chamber. The gas inlet zone is in any event preferably defined at its upstream extremity by a wall member having a concave internally-facing surface.

The apparatus components i to v set forth earlier in defining the atomisation apparatus in broad terms are preferably housed within a housing preferably comprising at least first and second separable housing portions, the apparatus outlet penetrating the housing for projecting a plume of atomised liquid therefrom into ambient. A body preferably defines said constriction and is preferably housed partly in each of said first and second housing portions. The body just mentioned may be housed in said first and second housing portions such that said constriction is disposed approximately at the junction between the two.

Preferably, a nozzle forms part of a nozzle assembly conveniently housed in the first of said first and second housing portions and the first housing portion is preferably downstream of said second housing portion (reading from the flow direction of said driving gas stream).

A liquid inlet is conveniently located in the first of said first and second housing portions and the first housing portion is preferably downstream of said second housing portion.

In a preferred form of the apparatus, a gas inlet is conveniently located in the second of said first and second housing portions and the first housing portion is preferably downstream of said second housing portion.

In another preferred form of the atomisation apparatus, the housing is fixed to the male component of a bayonet assembly for mounting the atomisation apparatus by marrying the male component of the bayonet assembly to a female component thereof, means preferably being provided in the male component of the bayonet assembly respectively for supplying gas and atomisation liquid to the apparatus. A female component of a

SUBSTITUTE SHEET (RULE 26) bayonet assembly is preferably mounted to a mounting platform for the apparatus and the male component of the same bayonet assembly is received within the female component and removably fixed in position. Passageways are preferably provided in the female component of the bayonet assembly respectively for connecting gas and atomisation liquid supplies to gas and liquid passageways provided in the male component of the bayonet assembly.

In a further and separate aspect of the invention, there is provided an atomiser which comprises: a first body having a liquid receiver for receiving liquid material to be atomised; a gas receiver for receiving gaseous material in which said liquid material is, in use of the atomiser, to be atomised as a discontinuous phase within a continuous phase of the gaseous material; means for producing within the first body an atomised mixture of said liquid material in said gaseous material; a nozzle from which to propel said mixture from the apparatus as a plume; a second body mounted to said first body; and a third body; said second and third bodies together, or said first, second and third bodies together, defining a liquid passageway for connecting said liquid receiver, and a gas passageway for connecting said gas receiver, at respective liquid and gas inlet orifices of said liquid and gas passageways, respectively, to a source external to the apparatus of said liquid material and a source external to the apparatus of said gaseous material: said second and said third bodies together forming a bayonet-and-socket assembly in which one of them comprises a bayonet sub-assembly and the other of them comprises a socket sub-assembly, the bayonet of the bayonet sub-assembly being alternately receivable in the socket of said socket sub-assembly and withdrawable therefrom, both the bayonet sub-assembly and the socket sub-assembly defining a part of each of said liquid and gas passageways, said bayonet-and-socket assembly having:

SUBSTITUTE SHEET (RULE 26) a first condition of assembly in which the bayonet of said bayonet sub-assembly is fixed in the socket of said socket sub-assembly to prevent the second and third bodies being separated one from the other and in which first condition said gas and liquid passageways are open for passage of gas and liquid, respectively, from said gas and liquid inlet orifices to said gas and liquid receivers, and a second condition of assembly of said bayonet-and-socket assembly in which the second and third bodies are separable one from the other, and said bayonet-and-socket assembly being: manipulable, whilst the bayonet of said bayonet sub-assembly remains disposed in the socket of said socket sub-assembly, to change the condition of said bayonet-and-socket assembly between said first and second conditions thereof.

The atomisation apparatus of the invention previously described may include any one or more (preferably all) the features of the atomiser just defined.

In preferred forms of the invention, the obround shape referred to for the gas transmission further pathway(s) is defined by two straight lines spaced apart in parallel, rather than series, opposed relationship to one another, and two arcs extending in one case between an end of one line and an end of the other and extending in the other case between the remaining line ends, the straight lines and the arcs together forming a continuous line defining an interior comprised of a rectangular domain which is disposed between, coextensive with and bordered by the straight lines on two opposed sides thereof, a convex domain conjoined to the rectangular domain on one of the other rectangular sides and bordered by one of the arcs and by the rectangular domain, and a further convex domain conjoined to the rectangular domain on the other one of the other rectangular sides and bordered by the other of the two arcs and by the rectangular domain.

SUBSTITUTE SHEET (RULE 26) It should be understood that the obround cross-sectional shape referred to herein in any of the embodiments described or referred to includes modified obround shapes in which an end cap may be in the form of an arc having a radius up to 10% greater (or smaller) than half the distance between the ends of the straight lines that arc joins or in which both arcs are of such form. In such modified obround shape, the end caps may differ one from the other but preferably are identical.

INTRODUCTION TO ASPECT TO ASPECT 2

The invention in this second aspect relates to atomisation of liquid in a gas stream and is more particularly concerned with an apparatus and method for effecting such atomisation which make use of a Venturi or other gas flow constriction. The invention is in particular, but not exclusively, concerned with a construction in which, in addition to a driving first gas stream transmitted to the gas flow constriction in a gas transmission first pathway, a bypass second gas transmission means comprising plural gas transmission further pathways (although a single pathway may also be used) bypasses the constriction to meet with Venturi output gas in a mixing zone downstream of the constriction. In the present invention, a constricted gas flow assembly is displaceable in relation to a nozzle to vary the flow capacity of a fluid passageway responsible for transmitting a fluid stream comprising atomised liquid into the accelerated driving gas stream produced by the Venturi or other gas flow constriction of the assembly.

SUMMARY OF ASPECT 2

The invention provides in this aspect an apparatus in which a key part is a gas flow constriction. This will generally be provided by means of a Venturi constriction but, in its broadest sense, the invention contemplates other forms of gas flow constriction (in which gas is accelerated to form an accelerated gas stream and a zone of reduced pressure) which may not be considered to be Venturi constrictions. By the expression "constricted gas flow assembly" the applicant intends to refer to any constricted gas flow device, module, body or assembly without, for example, limitation to whether it was made by a process of assembly or made as a single part.

SUBSTITUTE SHEET (RULE 26) According to this aspect of the invention, there is provided an atomisation apparatus comprising a constricted gas flow assembly comprising a body (pathway-defining means) provided with gas transmission means defining a driving gas transmission pathway, and a gas flow constriction (e.g. a Venturi constriction) disposed in said gas pathway, for receiving in said pathway and through said constriction a stream of a driving gas supplied to the apparatus, accelerating it through said gas flow constriction and discharging it from a driving gas transmission pathway outlet orifice of the constricted gas flow assembly as an accelerated driving gas stream; an atomisation chamber or zone disposed to receive said accelerated gas stream from said pathway outlet; a nozzle having an inlet orifice into a lumen thereof, said inlet orifice being disposed for receiving atomised material from said atomisation chamber or zone (and said atomisation zone conveniently being disposed between said nozzle inlet orifice and said pathway outlet orifice); the constricted gas flow assembly (or at least a part thereof) forming an element which is displaceable (e.g. in linear displacement) in relation to the nozzle to vary the flow cross-section of a fluid passageway of the apparatus provided for feeding a fluid stream comprising an atomisation liquid (and, optionally air or other gas supplied from a gas stream bypassing said gas flow constriction) into the accelerated driving gas stream, preferably at least tangentially into the accelerated driving gas stream (for example, perpendicularly to the direction of flow of that stream or, preferably, in a direction which opposes the direction of flow of that stream), in order to atomise said liquid in said gas stream in said atomisation chamber or zone for discharge from a lumen outlet orifice of said nozzle of a fluid discharge stream comprising a continuous gas phase having said atomisation liquid atomized therein as a discontinuous phase. The fluid passageway is preferably defined by said constricted gas flow assembly (or part thereof) and said nozzle assembly together with one another.

The fluid stream comprising an atomisation liquid will usually enter the accelerated driving gas stream at a location which is at or downstream of the driving gas pathway outlet orifice of the constricted gas flow assembly, and preferably in said atomisation zone.

It will be appreciated that atomisation is a process may continue in the upstream end portion of the nozzle lumen, where (as explained in detail hereinafter in the section

SUBSTITUTE SHEET (RULE 26) Liquid Zone 900 in the context of a specific embodiment), supersonic mixing velocity will usually continue to prevail.

The fluid passageway may transmit atomisation liquid together with non-driving gas and in practice this will normally be the case.

Although reference is made above to a part of the constricted gas flow assembly being displaceable, the constricted gas flow assembly is normally a unitary component of the apparatus, which is displaceable in whole. References hereinafter to the constricted gas flow assembly in the context of its displaceability should be interpreted as references to the constricted gas flow assembly or part thereof (namely, the displaceable element referred to earlier) being displaceable but with the preference that the constricted gas flow assembly is displaceable in whole.

Conveniently, the driving gas transmission pathway has a downstream portion terminating in the pathway outlet orifice and which is disposed to direct the accelerated driving gas stream from the pathway outlet on an axial path which is coaxial with a longitudinal axis of at least an upstream portion of the nozzle lumen extending downstream of the lumen input orifice of the nozzle.

The driving gas transmission pathway and the nozzle lumen may have a common longitudinal axis over at least the extent of an upstream portion of the lumen extending downstream of the lumen input orifice of the nozzle and over at least a downstream portion of the driving gas transmission pathway which includes the gas flow constriction.

Preferably, the nozzle lumen and the driving gas transmission pathway are linear and inline. For example, the driving gas transmission pathway and the nozzle lumen may have a common longitudinal axis extending from a gas input orifice for the gas transmission pathway to the lumen outlet orifice of the nozzle.

In a preferred embodiment, the apparatus includes further gas transmission means defining one or more gas transmission further pathways, preferably plural such further

SUBSTITUTE SHEET (RULE 26) pathways, each extending between an inlet orifice thereof and an outlet orifice thereof, the one or more further pathways being disposed for transmitting, to a fluid-receiving apparatus zone and in one or more respective further gas streams, further gas supplied to the apparatus, a liquid transmission pathway optionally being provided in the apparatus and disposed to transmit atomisation liquid to the fluid-receiving zone whereby to pre-mix the further gas and the atomisation liquid together therein for transmission to the atomisation zone by way of the fluid passageway.

Preferably, at least one gas transmission further pathway has an obround or oval cross- sectional shape throughout at least a downstream length portion thereof extending in an upstream direction from the outlet orifice of the gas transmission further pathway opening to the fluid-receiving zone, the obround or oval cross-sectional shape having the same orientation throughout that downstream length portion.

The pathway downstream length portion conveniently extends in an upstream direction from the gas transmission further pathway outlet orifice for a distance of at least 40% of the total length of its gas transmission further pathway, most conveniently for a distance of at least 50% of the total length of its gas transmission further pathway.

For example, the pathway downstream length portion may extend to at least 75% of the total length of its gas transmission further pathway. It is most preferred that pathway downstream length portion occupies the entire or substantially the entire length of its gas transmission further pathway.

The cross-sectional area of the pathway downstream length portion, whether or not of obround or oval cross-section, preferably diminishes, in the case of one or more of the gas transmission further pathways, linearly in a downstream direction over at least a downstream portion of the gas transmission further pathway. It is preferred that the tapering be applied only to the pathway lengths which have an obround or oval crosssection; in that case, a gas transmission further pathway will conveniently be one having a cross-section which diminishes linearly in a downstream direction over at least a subportion of the pathway downstream length portion extending in an upstream direction from the outlet orifice of the gas transmission further pathway.

SUBSTITUTE SHEET (RULE 26) Where the cross-sectional area of the pathway downstream length portion diminishes as just described, that downstream sub- portion of the pathway downstream length portion extends in an upstream direction from the outlet orifice and has an extent along the length of the pathway equal to, for example, at least 75% of that of the pathway downstream length portion. However, the downstream sub- portion preferably extends in an upstream direction from the outlet orifice with an extent along the length of the pathway downstream length portion equal to all or substantially all of the extent of the pathway downstream length portion.

The downstream length portion of at least one the gas transmission further pathway preferably has a cross-sectional area which conveniently diminishes linearly by an amount of from 25% to 50% , for example an amount of from 30% to 40%, in a downstream direction over at least the downstream sub-portion of the downstream length portion of the gas transmission further pathway, the sub-portion extending in an upstream direction from the outlet orifice of the gas transmission further pathway.

Conveniently, the cross-sectional area of the downstream pathway sub-portion reduces such that one or both, for example both, of the following dimensions of the obround or oval diminish linearly in a downstream direction throughout the length of the downstream sub-portion, namely: (i) the length of a line joining the centres of the end cap arcs and passing at all points midway between the sides of the obround or oval which join those arcs and (ii) the length of a line which dissects the previously mentioned line and extends between the mid-points of the sides of the obround or oval.

Referring to the configuration of the obround or oval shapes mentioned earlier, the length of a straight line joining the centres of the end cap arcs of the obround or oval and passing at all points midway between the sides of the obround or oval which join the arcs is conveniently from 1.05X to 1.25X (preferably, 1.10X to 1.20X) the length of a straight line which dissects the previously mentioned straight line joining the centres of the end cap arcs and extends between the mid-points of the sides of the obround or oval. Most preferably, wherein the length of the straight line joining the centres of the end cap arcs

SUBSTITUTE SHEET (RULE 26) of the obround or oval and passing at all points midway between the sides of the obround or oval which join the arcs is about 1.15X the length of the straight line which dissects the previously mentioned straight line joining the centres of the end cap arcs and extends between the mid-points of the sides of the obround or oval.

In preferred forms of the invention, the obround shape referred to for the gas transmission further pathway(s) is defined by two straight lines spaced apart in parallel, rather than series, opposed relationship to one another, and two arcs extending in one case between an end of one line and an end of the other and extending in the other case between the remaining line ends, the straight lines and the arcs together forming a continuous line defining an interior comprised of a rectangular domain which is disposed between, coextensive with and bordered by the straight lines on two opposed sides thereof, a convex domain conjoined to the rectangular domain on one of the other rectangular sides and bordered by one of the arcs and by the rectangular domain, and a further convex domain conjoined to the rectangular domain on the other one of the other rectangular sides and bordered by the other of the two arcs and by the rectangular domain.

It should be understood that the obround cross-sectional shape referred to herein in any of the embodiments described or referred to includes modified obround shapes in which an end cap may be in the form of an arc having a radius up to 10% greater (or smaller) than half the distance between the ends of the straight lines that arc joins or in which both arcs are of such form. In such modified obround shape, the end caps may differ one from the other but preferably are identical.

Conveniently, each the gas transmission further pathway may be linear from its inlet orifice to its outlet orifice and the central longitudinal axis of each the gas transmission further pathway is conveniently parallel to the central longitudinal axes of all the other the gas transmission further pathways.

Preferably, the further gas transmission means defines plural gas transmission further pathways for transmitting the non-driving bypass gas in respective further gas streams from respective inlet orifices to respective outlet orifices of respective the gas

SUBSTITUTE SHEET (RULE 26) transmission further pathways. When this is the case, the plural gas transmission further pathways are preferably comprised in a gas transmission further pathway array of the plural gas transmission further pathways. In particular, the plural gas transmission further pathways are preferably arrayed in the gas transmission further pathway array in equally spaced apart relationship with respect to one another.

In a preferred embodiment, the plural gas transmission further pathways are arranged about, and so that their axes are parallel to, the surface of a virtual parallel-sided cylinder of circular or rectangular base. In this case, the atomization apparatus is conveniently one in which the gas transmission first pathway is arranged to transmit the first gas stream on a first gas stream flow path to the constriction, which flow path is coaxial with the central axis of the virtual cylinder.

A preferred form of the above is an atomization apparatus in which the virtual cylinder is a right cylinder of circular cross-section and, at each point of cross-section crosssectioning all of the gas transmission further pathways through their the respective pathway downstream length portions, each obround or oval is intersected by a respective radius which (i) extends from the cylinder axis to the midpoint of the longitudinal axis of the obround or oval connecting the end caps thereof, (ii) is of the same length between those axes as all the other radii and (iii) intersects the obround or oval longitudinal axis at a right angle.

In a particular embodiment of the invention, all the gas transmission further pathways have an obround or oval cross-sectional shape throughout at least a downstream length portion thereof extending in an upstream direction from an outlet orifice thereof through which bypass gas is delivered to the pre-mixing region, the obround or oval cross-sectional shape having the same orientation throughout that downstream length portion. In that embodiment, at, each point of array cross-section, the longitudinal axes of the obrounds or ovals in aggregate form a discontinuous virtual line the interruptions in which are of equal magnitude to one another and represent in each instance the spacing between one gas transmission further pathway and a next adjacent gas transmission further pathway of the plurality thereof at that common point of cross-section, each such gas transmission

SUBSTITUTE SHEET (RULE 26) further pathway being identical in configuration to all the other the gas transmission further pathways.

Preferably, all the gas transmission further pathways forming part of the plurality of the gas transmission further pathways originate in inlet orifices at a gas inlet gallery of the apparatus comprising a gas inlet orifice respective to each of the gas transmission further pathways.

It is also preferred that all gas transmission further pathways forming part of the plurality of the gas transmission further pathways terminate in outlet orifices at a gas outlet gallery of the apparatus comprising a gas outlet orifice respective to each of the gas transmission further pathways.

Accordingly, a preferred embodiment of the invention is an atomisation apparatus in which all the gas transmission further pathways originate in inlet orifices at a gas inlet gallery of the apparatus comprising a gas inlet orifice respective to each of the gas transmission further pathways and terminate in outlet orifices at a gas outlet gallery of the apparatus comprising a gas outlet orifice respective to each of the gas transmission further pathways, the gas inlet gallery inlet orifices and the gas outlet gallery outlet orifices are all preferably arrayed in respective circular arrays.

Conveniently, the gas pathway-defining means defines, as at least part of the driving gas transmission pathway, a gas convergence zone tapering in cross-section from a convergence zone upstream mouth for receiving compressed gas supplied to the apparatus to a minimum cross-section downstream thereof at the mouth of the constriction. The ratio between the convergence zone cross-sectional area at its mouth and its cross-sectional area at the mouth of the constriction is, for example, from 2.75:1 to 2.60:1.

The convergence zone is , for example, defined by one or more device walls enclosing a frusto-conical void which opens at its upstream extremity represented by the base of the frusto-cone in the convergence zone mouth and which opens at its the downstream extremity to the constriction.

SUBSTITUTE SHEET (RULE 26) Referring to the convergence zone, all of plural gas transmission further pathways conveniently originate in a gas inlet gallery comprising an array of gas inlet orifices each one thereof respective to one of the gas transmission further pathways and the array circumscribes the gas convergence zone at a location proximate its upstream mouth.

The convergence zone mouth will commonly form a sole inlet to the convergence zone.

Where there are plural gas transmission further pathways, they may preferably provide a total gas transmission further pathway inlet cross-sectional area which is equal to that of the convergence zone at its narrowest, individual gas transmission further pathway inlet cross-sectional area in the case of each the gas transmission further pathway being measured at the most upstream point at which that gas transmission further pathway has a cross-section plane intersecting all of its sides and intersecting the gas transmission further pathway longitudinal axis orthogonally.

In a further particular embodiment of the invention, an atomisation apparatus for atomising an atomisation liquid as a discontinuous phase and for discharging atomised liquid and gas as a plume comprises:

(a) gas pathway-defining means defining a gas transmission first pathway for transmission in a first gas stream of gas supplied to the apparatus and having a flow constriction disposed in the gas transmission first pathway for receiving the first gas stream therethrough with increased velocity as a convergent driving gas stream (the pathway-defining means forming part of the previously mentioned constricted gas flow assembly);

(b) atomisation liquid supply means for supplying to a pre-mixing region of the apparatus a stream of atomisation liquid supplied to the apparatus;

(c) an atomisation region disposed to receive the convergent driving gas stream from an exit of the constriction;

SUBSTITUTE SHEET (RULE 26) (d) further fluid transmission means for transmission of materials for atomisation to the atomisation region, the further fluid transmission means comprising the first and second further apparatus parts defined below: i. a first apparatus part which comprises plural gas transmission further pathways formed in the apparatus (the form of the gas transmission further pathways being preferably obround or oval as previously described), or at least one such further pathway, for transmission, in respective further gas streams to the second apparatus part of gas supplied to the apparatus, the further gas streams bypassing the flow constriction, and ii. a second apparatus part which comprises the pre-mixing region and is disposed to receive, for mixing together therein to form a pre-mixture, the bypass gas and liquid of the liquid stream received from the atomisation liquid supply means to form a pre-mixture and for transmitting the pre-mixture to the atomisation region for atomisation of the liquid thereof in a continuous gas phase; and

(e) a nozzle for receiving through an inlet orifice thereof admixed gas and atomised liquid from the atomisation region and having an outlet orifice from which to discharge said plume.

Of course, as mentioned previously, atomisation may continue in the most upstream end portion of the nozzle lumen.

The premixture is preferably introduced into the increased velocity convergent driving gas stream, at least tangentially of that gas stream (for example, perpendicularly to the direction of flow of that stream or, preferably, in a direction which opposes the direction of flow of that stream).

SUBSTITUTE SHEET (RULE 26) Referring to the further preferred embodiment just described, it is preferred that a surface of the pathway-defining means and a further apparatus surface together define the fluid passageway or at least part thereof. In that case, the further apparatus surface is preferably a surface of the nozzle.

Preferably, the nozzle and the constricted gas flow assembly (e.g. the body defining the driving gas transmission pathway) , together, define the fluid passageway, for example, by means of a conical surface of each, which surfaces are spaced apart to form at least part of the fluid passageway between e.g. a the conical surfaces.

The nozzle may have a surface, which together with the further apparatus surface referred to, defines a space therebetween which separates them and forms at least part of the fluid passageway, both the surfaces being of frusto-conical form and the further apparatus surface defining a frusto-conical chamber in which the nozzle, or the part of the nozzle which presents its the frusto-conical surface, is received to form the space, the chamberdefining apparatus surface forming part of the constricted flow assembly (e.g. of the gas pathway-defining means), and the frusto-conical chamber increasing in cross-sectional area in a downstream direction from a minimum cross-sectional area at an end open to receive admixed gas and atomized liquid from the atomization chamber to a maximum at a downstream chamber mouth whereby the space can be changed in size by displacement of the constricted flow assembly towards or away from the nozzle surface.

The nozzle surface and the further apparatus surface conveniently remain in parallel opposed relation to one another, preferably defining the atomisation chamber between them, when the constricted flow assembly is displaced.

In any of the embodiments of the atomisation apparatus of the invention described earlier or elsewhere herein, the constricted gas flow assembly will preferably provide a driving gas transmission pathway which is in-line with the nozzle lumen, the gas transmission further pathway being displaceable upon that line.

SUBSTITUTE SHEET (RULE 26) The chamber referred to above preferably is defined by one or more chamber walls which enclose a frusto-conical void which opens at its upstream extremity to receive the admixed gas and atomized liquid from the atomization chamber and which is open at its downstream extremity represented by the base of the frusto-cone to the pre-mixing region.

The plural gas transmission further pathways conveniently all terminate in a gas outlet gallery comprising an array of gas outlet orifices each one thereof respective to one of the gas transmission further pathways and the array circumscribing the chamber at a location proximate its downstream mouth.

At least one gas transmission further pathway preferably has the previously mentioned obround or oval cross-sectional shape throughout at least a downstream length portion comprised in the gas transmission further pathway and extending in an upstream direction from an outlet orifice of the gas transmission further, a linear reduction in cross- sectional area being suffered, in a downstream direction, of at least one gas transmission further pathway, in at least a downstream sub-portion of the gas transmission further pathway downstream length portion, the reduction in cross-section taking the form of a reduction in one or both of width and length of the obround or oval. The width reduction referred to is conveniently the same in magnitude in the case of each of plural such gas transmission further pathways and the length reduction is conveniently the same in magnitude in the case of each of plural such gas transmission further pathways.

The ratio between the cross-sectional area of the outlet orifice, in the case of one or more the gas transmission further pathways, and that of a corresponding gas transmission further pathway inlet orifice is from 1 : 1.5 to 1 : 2.0 and the cross-sectional area reduces linearly between the orifices.

The gas transmission further pathways are preferably each defined in and by a body of the apparatus which body also defines the constriction and is separable from the rest of the apparatus.

SUBSTITUTE SHEET (RULE 26) Atomisation apparatus are preferred in which the gas transmission further pathways are each defined in and by a body of the apparatus which also preferably defines the constriction and which is separable from the rest of the apparatus. However, the gas transmission further pathways, more generally, may be formed in the body of an apparatus element or between two conjoined apparatus elements which come together to define the pathway as a region of materials removal or omission in one or both of said conjoined apparatus elements; for example, the pathway may be a channel, in one element or the other, which is closed by the other element to form a conduit or, alternatively, a conduit may be formed between two elements each of which is formed with part of the cross-section of the conduit so that a conduit in whole can be formed by the marriage of the two elements together in such a manner that the two-part cross sections of the conduit become integrated.

In a particular embodiment, a nozzle assembly comprising the nozzle includes a collar perforated by one or a plurality of liquid transmission pathways connecting a chamber for atomisation liquid disposed in the apparatus on the downstream side of the collar, reading from the flow direction of the driving gas stream, with the fluid passageway disposed on the upstream side of the collar, again reading from the flow direction of the driving gas stream, the connection being optionally via an intermediate zone of the apparatus. In terms of the materials from which the apparatus should be made, at least the gascontacting surfaces of the means defining the gas transmission pathway are preferably made of stainless steel.

In a preferred embodiment of the invention, atomisation apparatus is one in which:

(i) a first module comprises a nozzle;

(ii) a second module comprises a first element defining the driving gas transmission pathway, a Venturi constriction being provided in the gas transmission pathway for receiving the gas stream and outputting it to the atomisation zone, the fluid passageway and optionally a bypass gas stream pathway along which to transmit a bypass gas stream to the fluid passageway, bypassing the Venturi;

SUBSTITUTE SHEET (RULE 26) (iii) the first and second modules together define the fluid passageway as a separation between a surface of one of the first and second modules and an opposed surface of the other,

(iv) the second module includes a second element for connection to a source of rotational drive and for converting it to linear displacement of the second module relative to the first module, and

(v) the second module is so displaceable relative to the first module between a first position of the second module, in which it is spaced apart from the first module by a first separation and the fluid passageway has a first fluid flow volume capacity, and a second position of the second module, in which it is spaced apart from the first module by a second and different separation and the fluid passageway has a second fluid flow capacity different to the first atomisation liquid flow capacity, the second module optionally having a third position in which it is not spaced apart from the first module and in which fluid cannot flow to the atomisation zone.

A gas inlet zone is preferably provided for receiving gas supplied to the apparatus and supplying the received gas to the driving gas transmission pathway and to optional further gas transmission means bypassing the flow constriction. The gas inlet zone is conveniently defined by an open-sided chamber through whose open sides the gas supplied to the gas inlet zone can enter the chamber, and the gas inlet zone is preferably defined at its upstream extremity by a wall member having a concave internally-facing surface.

The atomisation apparatus preferably includes a housing comprising at least first and second separable housing portions, at least the gas pathway-defining means, the atomisation zone and the nozzle being housed in the housing. In particular, a body which defines the constriction is conveniently housed partly in each of the first and second housing portion.

The flow constriction is preferably disposed in the housing at approximately the junction between the first and second housing portions .

SUBSTITUTE SHEET (RULE 26) The nozzle may preferably form part of a nozzle assembly housed in the first of the first and second housing portions, the first housing portion preferably being downstream of the second housing portion, reading from the flow direction of the driving gas stream.

A liquid inlet for atomisation liquid is preferably located in the first of the first and second housing portions, the first housing portion preferably being downstream of the second housing portion.

The gas inlet may be located in the second of the first and second housing portions and the first housing portion located downstream of the second housing portion.

The housing is preferably fixed to the male component of a bayonet assembly for mounting the atomisation apparatus by marrying the male component of the bayonet assembly to a female component thereof. Means are preferably provided in the male component of the bayonet assembly respectively for supplying gas and atomisation liquid to the apparatus.

A female component of a bayonet assembly is preferably mounted to a mounting platform for the apparatus and the male component of the same bayonet assembly is received within the female component and removably fixed in position.

Passageways conveniently are provided in the female component of the bayonet assembly respectively for connecting gas and atomisation liquid supplies to gas and liquid passageways are provided in the male component of the bayonet assembly.

In an embodiment of the invention, a first body has a liquid receiver for receiving the liquid material for supply to the fluid passageway and a gas receiver for receiving the gas which is supplied to the apparatus; a second body is mounted to the first body; and a third body is also provided;

SUBSTITUTE SHEET (RULE 26) the second and third bodies together, or the first, second and third bodies together, defining a liquid passageway for connecting the liquid receiver, and a gas passageway for connecting the gas receiver, at respective liquid and gas inlet orifices of the liquid and gas passageways, respectively, to a source external to the apparatus of the liquid material and a source external to the apparatus of the gaseous material: the second and the third bodies together forming a bayonet-and-socket assembly in which one of them comprises a bayonet sub-assembly and the other of them comprises a socket sub-assembly, the bayonet of the bayonet sub-assembly being alternately receivable in the socket of the socket sub-assembly and withdrawable therefrom, both the bayonet sub-assembly and the socket sub-assembly defining a part of each of the liquid and gas passageways, the bayonet-and-socket assembly having: a first condition of assembly in which the bayonet of the bayonet subassembly is fixed in the socket of the socket sub-assembly to prevent the second and third bodies being separated one from the other and in which first condition the gas and liquid passageways are open for passage of gas and liquid, respectively, from the gas and liquid inlet orifices to the gas and liquid receivers, and a second condition of assembly of the bayonet-and-socket assembly in which the second and third bodies are separable one from the other, and the bayonet-and-socket assembly being: manipulable, whilst the bayonet of the bayonet sub-assembly remains disposed in the socket of the socket sub-assembly, to change the condition of the bayonet-and-socket assembly between the first and second conditions thereof.

The displaceable element (e.g. the constricted gas flow assembly or the pathway-defining means) is preferably mounted for driven displacement by drive means of the apparatus or through coupling means of the apparatus for coupling the pathway-defining means to

SUBSTITUTE SHEET (RULE 26) extrinsic drive means. The drive means in any embodiment described is preferably rotary drive means.

The displaceable element (e.g. the constricted gas flow assembly or the pathway-defining means thereof) is preferably mounted for linear displacement by rotary drive means, rotary-to-linear drive conversion means being provided in the apparatus whereby it (or the constricted gas flow assembly) may be linearly displaced to vary liquid flow in the fluid passageway feeding into the accelerated driving gas stream.

The drive conversion means preferably comprises a rotatable first element mounted to be rotatable by the rotary drive means or forming a rotatable part thereof and a second element drivingly engageable with the first element so as to suffer linear displacement with rotation of the first element. The second element conveniently forms part of the constricted gas flow assembly or is a separate part engaged or engageable therewith so as to transfer the suffered linear displacement to the pathway-defining means.

One of the first and second elements is preferably a drive barrel and the other of the first and second elements is a drive shaft, the drive shaft being threadedly engaged with the drive barrel, one of the drive barrel and the drive shaft being a driven member to be driven by the rotary drive means and the other being a driving member for displacing the constricted gas flow assembly or other displaceable element in linear fashion.

The constricted gas flow assembly is conveniently displaceable in relation to the nozzle by micrometre adjustment.

The constricted gas flow assembly is best disposed so as to be reciprocally displaceable in relation to the nozzle in a direction to increase the flow cross-section of the fluid passageway or to decrease the flow cross-section of the fluid passageway.

INTRODUCTION ASPECT 3

SUBSTITUTE SHEET (RULE 26) The invention in this third aspect relates to atomisation of liquid in a gas stream and is more particularly concerned with an apparatus and method for effecting such atomisation which make use of a Venturi or other gas flow constriction.

The invention in this aspect is in particular concerned with a construction which offers a simplicity in which the interior of an apparatus housing can easily be accessed with low levels of disassembly in order to remove a nozzle assembly forming a key part of the apparatus, for example for replacement or for cleaning and re-insertion. Nozzle replacement is a common requirement, in particular to cater for atomization liquids of different types having different properties and different requirements in terms of ideal application.

SUMMARY OF ASPECT 3

The invention provides in this third aspect an apparatus in which a key part is a gas flow constriction provided as part of a constricted gas flow assembly. This will generally be provided by means of a Venturi constriction but, in its broadest sense, the invention contemplates other forms of gas flow constriction (in which gas is accelerated) which may not be considered to be Venturi constrictions. By the expression "constricted gas flow assembly" the applicant intends to refer to any constricted gas flow device, module, body or assembly without, for example, limitation to whether it was made by a process of assembly or made as a single part.

According to the invention in this one of its aspects, there is provided atomisation apparatus comprising a housing which comprises a downstream first housing part and an upstream second housing part; said first and second housing parts together enclosing a housing chamber and preferably being separable one from the other; a nozzle housed in said housing chamber and positionally retained therein by the first housing part; said nozzle having an outlet thereof opening to ambient through an aperture of said first housing part; a constricted gas flow assembly comprising a body provided with gas transmission means defining a driving gas transmission pathway, and a gas flow

SUBSTITUTE SHEET (RULE 26) constriction disposed in said gas pathway, for receiving a stream of a driving gas supplied to the apparatus, accelerating it through said gas flow constriction and discharging it from a driving gas transmission pathway outlet orifice of the constricted gas flow assembly as an accelerated driving gas stream; the nozzle having an inlet orifice into a lumen thereof, said nozzle being unattached, or substantially unattached, to the constricted gas flow assembly (or at least permitting relative movement between them which allows the spacing apart referred to below to be increased or decreased) and having its nozzle inlet orifice opposed to the driving gas pathway outlet orifice of the constricted gas flow assembly and spaced apart from said driving gas pathway outlet orifice by an atomisation chamber disposed between said nozzle inlet orifice and said driving gas pathway outlet orifice for receiving, into said atomisation chamber for atomisation, said accelerated driving gas stream and, by way of a fluid passageway of the apparatus feeding into that accelerated driving gas stream, preferably at least tangentially into the accelerated driving gas stream (for example, perpendicularly to the direction of flow of that stream or, preferably, in a direction which opposes the direction of flow of that stream), a fluid stream comprising an atomisation liquid (and, optionally air or other gas supplied from a gas stream bypassing said gas flow constriction), said nozzle inlet orifice disposed to receive atomised material from said atomisation chamber and the nozzle having a lumen outlet orifice for discharge of a fluid discharge stream comprising a continuous gas phase having said atomisation liquid atomized therein as a discontinuous phase.

In the preferred embodiment, the two housing parts are fixed together in the assembled apparatus by releasable connection means and are separable one from the other following release of said connection means into a first housing part in which the nozzle is preferably retained by interaction between one or more first housing part surfaces and one or more nozzle surfaces, with the constricted gas flow assembly dissociated from the nozzle and remaining housed by, or at least retained by, the separate second housing part and with the apparatus surfaces defining the atomisation zone or chamber in the assembled apparatus displaced so that the atomisation zone or chamber is no longer extant.

SUBSTITUTE SHEET (RULE 26) It will be appreciated that atomisation is a process may continue in the upstream end portion of the nozzle lumen, where (as explained in detail hereinafter in the section "Liquid Zone 900" in the context of a specific embodiment), supersonic mixing velocity will usually continue to prevail.

The fluid stream comprising an atomisation liquid will usually enter the accelerated driving gas stream at a location which is at or downstream of the driving gas pathway outlet orifice of the constricted gas flow assembly (or it might be at the location of that outlet orifice), and preferably in said atomisation zone.

The driving gas stream will conveniently have a direction which is in-line with said lumen of the nozzle.

The nozzle is conveniently positionally retained by the first housing part by engagement of an abutment surface of the first housing part with an abutment surface of the nozzle.

The first housing part is preferably provided with a receiver in said housing chamber for atomisation liquid, the fluid passageway connecting said receiver to the atomisation zone, for example, one or more passageways (e.g. one or more conduits), preferably a plurality of them.

The second housing part is conveniently provided with a receiver in said housing chamber for driving gas, said receiver disposed to supply driving gas to said driving gas pathway.

Conveniently, the first and second housing parts are formed with connection means for use in connecting supplies of atomisation liquid and gas to the apparatus.

The first and second housing parts are preferably fixed one to the other by fixings external to the housing and, however they are fixed, they preferably join at a planar interface when unified.

SUBSTITUTE SHEET (RULE 26) The release of the external fixings just mentioned preferably enables said first and second housing parts to be separated for access to apparatus components which are housed in the housing chamber when said first and second housing parts are unified to define it.

In one form of the apparatus of the invention, the driving gas pathway has a downstream portion terminating in said driving gas pathway outlet orifice and which is disposed to direct said accelerated driving gas stream from said driving gas pathway outlet on an axial path which is coaxial with a longitudinal axis of at least an upstream portion of said lumen of said nozzle which upstream lumen portion opens at said nozzle inlet orifice and extends downstream of said nozzle inlet orifice.

The driving gas transmission pathway and the nozzle lumen may have a common longitudinal axis over at least the extent of an upstream portion of the lumen extending downstream of the lumen input orifice of the nozzle and extending over at least a downstream portion of the driving gas transmission pathway which includes the gas flow constriction.

Preferably, the nozzle lumen and the driving gas transmission pathway are linear and inline. For example, the driving gas transmission pathway and the nozzle lumen may have a common longitudinal axis extending from a gas input orifice for the gas transmission pathway to the lumen outlet orifice of the nozzle.

The driving gas pathway and said nozzle lumen preferably has a common longitudinal axis over at least the extent of an upstream portion of the lumen extending from a gas inlet orifice for said driving gas pathway to said nozzle inlet.

In a preferred embodiment, the apparatus of the invention includes further gas transmission means defining one or more gas transmission further pathways (e.g. conduits), preferably plural such pathways,, each extending between an inlet orifice thereof and an outlet orifice thereof, said one or more further pathways being disposed for transmitting, to a fluid-receiving apparatus zone and in one or more respective further gas streams which bypass said gas flow constriction, further gas supplied to the apparatus,

SUBSTITUTE SHEET (RULE 26) a liquid transmission pathway being provided in the apparatus and disposed to transmit atomisation liquid to said fluid-receiving zone whereby to pre-mix said further gas and said atomisation liquid together therein for transmission to said atomisation zone by way of said fluid passageway.

Preferably, at least one said gas transmission further pathway has an obround or oval cross-sectional shape throughout at least a downstream length portion thereof extending in an upstream direction from the outlet orifice of the gas transmission further pathway opening to said fluid-receiving zone, said obround or oval cross-sectional shape having the same orientation throughout that downstream length portion.

The pathway downstream length portion conveniently extends in an upstream direction from said gas transmission further pathway outlet orifice for a distance of at least 40% of the total length of its gas transmission further pathway, most conveniently for a distance of at least 50% of the total length of its gas transmission further pathway.

For example, the downstream length portion may extend to at least 75% of the total length of its gas transmission further pathway. It is most preferred that the pathway downstream length portion occupies the entire or substantially the entire length of its gas transmission further pathway.

The cross-sectional area of the pathway downstream length portion, whether or not of obround or oval cross-section, preferably diminishes, in the case of one or more of the gas transmission further pathways, linearly in a downstream direction over at least a downstream portion of the gas transmission further pathway. It is preferred that the tapering be applied only to the pathway lengths which have an obround or oval crosssection; in that case, a gas transmission further pathway will conveniently be one having a cross-section which diminishes linearly in a downstream direction over at least a subportion of the pathway downstream length portion extending in an upstream direction from the outlet orifice of the gas transmission further pathway.

Where the cross-sectional area of the pathway downstream length portion diminishes as just described, the pathway downstream length portion or sub-portion extends in an

SUBSTITUTE SHEET (RULE 26) upstream direction from the gas transmission further pathway outlet orifice and has an extent along the length of the pathway equal to, for example, at least 75% of that of the pathway downstream length portion. However, the downstream portion or sub-portion preferably extends in an upstream direction from the outlet orifice with an extent along the length of the pathway downstream length portion equal to all or substantially all of the extent of the pathway downstream length portion.

The downstream length portion of at least one gas transmission further pathway preferably has a cross-sectional area which conveniently diminishes linearly by an amount of from 25% to 50% over the longitudinal extent of the cross-section reduction, for example an amount of from 30% to 40% in a downstream direction extending in an upstream direction from the outlet orifice of the gas transmission further pathway.

Conveniently, the cross-sectional area of the gas transmission further pathway reduces over the longitudinal extent of the obround or oval sub-portion referred to such that one or both, for example both, of the following dimensions of the obround or oval diminish linearly in a downstream direction, e.g. over the length of the downstream sub-portion, namely: (i) the length of a line joining the centres of the end cap arcs and passing at all points midway between the sides of the obround or oval which join those arcs and (ii) the length of a line which dissects the previously mentioned line and extends between the mid-points of the sides of the obround or oval.

Referring to the configuration of the obround or oval shapes mentioned earlier, the length of a straight line joining the centres of the end cap arcs of the obround or oval and passing at all points midway between the sides of the obround or oval which join the arcs is conveniently from 1.05X to 1.25X (preferably, 1.10X to 1.20X) the length of a straight line which dissects the previously mentioned straight line joining the centres of the end cap arcs and extends between the mid-points of the sides of the obround or oval. Most preferably, the length of the straight line joining the centres of the end cap arcs of the obround or oval and passing at all points midway between the sides of the obround or oval which join the arcs is about 1.15X the length of the straight line which dissects the

SUBSTITUTE SHEET (RULE 26) previously mentioned straight line joining the centres of the end cap arcs and extends between the mid-points of the sides of the obround or oval.

It should be understood that the obround cross-sectional shape referred to herein in any of the embodiments described or referred to includes modified obround shapes in which an end cap may be in the form of an arc having a radius up to 10% greater (or smaller) than half the distance between the ends of the straight lines that arc joins or in which both arcs are of such form. In such modified obround shape, the end caps may differ one from the other but preferably are identical.

Conveniently, each gas transmission further pathway may be linear from its inlet orifice to its outlet orifice and the central longitudinal axis of each the gas transmission further pathway is conveniently parallel to the central longitudinal axes of all the other the gas transmission further pathways.

Preferably, the further gas transmission means defines plural gas transmission further pathways for transmitting said non-driving bypass gas in respective further gas streams from respective inlet orifices to respective outlet orifices of respective said gas transmission further pathways.

When this is the case, the plural gas transmission further pathways are preferably comprised in a gas transmission further pathway array of the plural gas transmission further pathways. In particular, the plural gas transmission further pathways are preferably arrayed in the gas transmission further pathway array in equally spaced apart relationship with respect to one another.

In a preferred embodiment, the plural gas transmission further pathways are arranged about, and so that their axes are parallel to, the surface of a virtual parallel-sided cylinder of circular or rectangular base. In this case, the atomization apparatus is conveniently one in which the driving gas pathway is arranged to transmit said driving gas stream on a gas stream flow path to the constriction, which flow path is coaxial with the central axis of said virtual cylinder.

SUBSTITUTE SHEET (RULE 26) A preferred form of the above is an atomisation apparatus in which the virtual cylinder is a right cylinder of circular cross-section and since, at each point of cross-section crosssectioning all of said gas transmission further pathways through their said respective pathway downstream length portions, each obround or oval is intersected by a respective radius which (i) extends from the cylinder axis to the midpoint of the longitudinal axis of the obround or oval connecting the end caps thereof, (ii) is of the same length between those axes as all the other radii and (iii) intersects the obround or oval longitudinal axis at a right angle.

In a particular embodiment of the invention, each of said plural said gas transmission further pathways has an obround or oval cross-sectional shape throughout at least a downstream length portion thereof extending in an upstream direction from an outlet orifice of the gas transmission further pathway through which bypass gas is delivered to said fluid-receiving zone, said obround or oval cross-sectional shape having the same orientation throughout that downstream length portion. In that embodiment, at each said point of array cross-section, the longitudinal axes of the obrounds or ovals in aggregate form a discontinuous virtual line the interruptions in which are of equal magnitude to one another and represent in each instance the spacing between one said gas transmission further pathway and a next adjacent said gas transmission further pathway of the plurality thereof at that common point of cross-section, each said gas transmission further pathway being identical in configuration to all the other said gas transmission further pathways, the latter (i.e. identity of configuration) being a generally preferred feature of the apparatus beyond the embodiment just described).

Preferably, all said gas transmission further pathways forming said plurality of said gas transmission further pathways originate in inlet orifices at a gas inlet gallery of the apparatus comprising a gas inlet orifice respective to each of said gas transmission further pathways.

It is also preferred that all said gas transmission further pathways forming part of said plurality of said gas transmission further pathways terminate in outlet orifices at a gas

SUBSTITUTE SHEET (RULE 26) outlet gallery of the apparatus comprising a gas outlet orifice respective to each of said gas transmission further pathways.

Accordingly, a preferred embodiment of the invention is an atomisation apparatus in which all said gas transmission further pathways originate in inlet orifices at a gas inlet gallery of the apparatus comprising a gas inlet orifice respective to each of said gas transmission further pathways and terminate in outlet orifices at a gas outlet gallery of the apparatus comprising a gas outlet orifice respective to each of said gas transmission further pathways, the gas inlet gallery inlet orifices and the gas outlet gallery outlet orifices all preferably being arrayed in respective circular arrays.

Conveniently, the constricted gas flow assembly defines, as at least part of said driving gas pathway, a gas convergence zone tapering in cross-section from a convergence zone upstream mouth for receiving compressed gas supplied to the apparatus to a minimum cross-section downstream thereof at the mouth of the constriction. The ratio between the convergence zone cross-sectional area at its mouth and its cross-sectional area at the mouth of the constriction is, for example, from 2.75:1 to 2.60:1.

The convergence zone is, for example, defined by one or more apparatus walls enclosing a frusto-conical void which opens at its upstream extremity represented by the base of the frusto-cone in said convergence zone mouth and which opens at its the downstream extremity to said constriction.

Referring to the convergence zone, all of plural gas transmission further pathways originate in a gas inlet gallery comprising an array of gas inlet orifices each one thereof respective to one of said gas transmission further pathways, said array circumscribing the gas convergence zone at a location proximate its upstream mouth.

The convergence zone mouth may form a sole inlet to the convergence zone.

Where there are plural gas transmission further pathways, they may preferably provide a total gas transmission further pathway inlet cross-sectional area which is equal to that of the convergence zone at its narrowest, individual gas transmission further pathway inlet

SUBSTITUTE SHEET (RULE 26) cross-sectional area in the case of each said gas transmission further pathway being measured at the most upstream point at which that gas transmission further pathway has a cross-section plane intersecting all of its sides and intersecting the gas transmission further pathway longitudinal axis orthogonally. The further gas transmission means are preferably provided by said constricted gas flow assembly.

The nozzle is preferably positionally retained by the first housing part and is not fixed to the second housing part.

The said housing parts are conveniently fixed together by fixing means which are external to said housing in the sense that they are there accessible for the purposes of release.

A preferred apparatus for atomising an atomisation liquid as a discontinuous phase and for discharging atomised liquid and gas as a plume, the apparatus comprises: - i. said gas transmission means; ii. atomisation liquid supply means, constituting said fluid passageway of the apparatus, for supplying to a pre-mixing region of the apparatus a stream of atomisation liquid supplied to the apparatus; iii. said atomisation chamber; iv. further fluid transmission means for transmission of materials for atomisation to said atomisation chamber, said further fluid transmission means comprising the first and second further apparatus parts defined below:

(a) a first apparatus part which comprises plural said gas transmission further pathways formed in the apparatus for transmission, in respective further gas streams to said second apparatus part, of gas supplied to the apparatus, said further gas streams bypassing said gas flow constriction, and

(b) a second apparatus part which comprises said pre-mixing region and is disposed to receive, for mixing together therein to form a pre-mixture, said bypass gas and liquid of said liquid stream received from said atomisation liquid supply means and for transmitting said pre-mixture to said atomisation chamber for atomisation of the liquid thereof in a continuous gas phase; and

SUBSTITUTE SHEET (RULE 26) v. a nozzle for receiving through an inlet orifice thereof admixed gas and atomised liquid from the atomisation chamber and having an outlet orifice from which to discharge said plume.

Of course, as mentioned previously, atomisation may continue in the most upstream end portion of the nozzle lumen.

The premixture is preferably introduced into the accelerated gas stream at least tangentially of that gas stream (for example, perpendicularly to the direction of flow of that stream or, preferably, in a direction which opposes the direction of flow of that stream).

Referring to the further preferred embodiment just described, it is preferred that a surface of the pathway-defining means and a further apparatus surface together define the atomisation liquid supply means or at least part thereof. In that case, the further apparatus surface is preferably a surface of the nozzle.

Conveniently a surface of the constricted gas flow assembly and a further apparatus surface together define said fluid passageway or at least part thereof. Most conveniently, the further apparatus surface is a surface of said nozzle. Preferably, the nozzle and the constricted gas flow assembly, together, define the fluid passageway by means of eg a conical surface of each, which surfaces are spaced apart to form at least part of the fluid passageway between the conical surfaces.

The nozzle may have a surface which, together with a further apparatus surface, defines a space therebetween which separates them and forms at least part of said fluid passageway, both said surfaces being of frusto-conical form and the further apparatus surface defining a frusto-conical chamber in which the part of the nozzle which presents its said frusto-conical surface is received to form said space, said chamber-defining apparatus surface forming part of said constricted gas flow assembly, said frusto-conical chamber increasing in cross-sectional area in a downstream direction from a minimum cross-sectional area at an end open to receive admixed gas and atomized liquid from said atomization chamber to a maximum at a frusto-conical downstream chamber mouth.

SUBSTITUTE SHEET (RULE 26) Preferably, the frusto-conical chamber is defined by one or more chamber walls which enclose a frusto-conical void which opens at its upstream extremity to receive said admixed gas and atomized liquid from said atomization chamber and which is open at its downstream extremity represented by the base of the frusto-cone to a pre-mixing region for pre-mixing gas with atomisation liquid and transmitting the resulting pre-mixture to said atomisation chamber.

Preferably, in either of the two embodiments described in the preceding two paragraphs, at least one and preferably plural gas transmission further pathways as previously described bypass said gas flow constriction and, in the case of plural gas transmission further pathways, they all preferably terminate in a gas outlet gallery comprising an array of gas outlet orifices each one thereof respective to a gas transmission further pathways, said array circumscribing said frusto-conical chamber at a location proximate its downstream mouth for pre-mixing gas with atomisation liquid and transmitting the resulting pre-mixture to said atomisation chamber.

At least one gas transmission further pathway is preferably disposed to transmit gas to said atomisation chamber in a stream which bypasses said gas flow constriction and said gas transmission further pathway preferably has said obround or oval cross-sectional shape throughout at least a downstream length portion comprised in the gas transmission further pathway and extending in an upstream direction from an outlet orifice of the gas transmission further pathway and wherein a linear reduction in cross-sectional area is suffered, in a downstream direction, of at least one said gas transmission further pathway, in at least a downstream sub-portion of said gas transmission further pathway downstream length portion, and takes the form of a reduction in one or both of width and length of the obround or oval. The width reduction is conveniently the same in magnitude in the case of each of plural such gas transmission further pathways and said length reduction is conveniently the same in magnitude in the case of each of plural such gas transmission further pathways.

The ratio between the cross-sectional area of the outlet orifice, in the case of one or more said gas transmission further pathways, and that of a corresponding gas transmission

SUBSTITUTE SHEET (RULE 26) further pathway inlet orifice is preferably from 1 : 1.5 to 1 : 2.0 and said cross-sectional area reduces linearly between said orifices.

In an embodiment of the atomisation apparatus according to Aspect 3 of the invention, the apparatus includes further gas transmission means defining one or more gas transmission further pathways, each extending between an inlet orifice thereof and an outlet orifice thereof, said one or more further pathways being disposed for transmitting, to a fluid-receiving apparatus zone and in one or more respective further gas streams which bypass said gas flow constriction, further gas supplied to the apparatus, a liquid transmission pathway being provided in the apparatus and disposed to transmit atomisation liquid to said fluid-receiving zone whereby to pre-mix said further gas and said atomisation liquid together therein for transmission to said atomisation zone by way of said fluid passageway, said gas transmission further pathways each being defined in and by a body of the apparatus, said body also defining the constriction and being preferably separable from the rest of the apparatus.

In another embodiment, the apparatus includes further gas transmission means defining one or more gas transmission further pathways, each extending between an inlet orifice thereof and an outlet orifice thereof, said one or more further pathways being disposed for transmitting, to a fluid-receiving apparatus zone and in one or more respective further gas streams which bypass said gas flow constriction, further gas supplied to the apparatus, a liquid transmission pathway being provided in the apparatus and disposed to transmit atomisation liquid to said fluid-receiving zone whereby to pre-mix said further gas and said atomisation liquid together therein for transmission to said atomisation zone by way of said fluid passageway, each gas transmission further pathway being formed in the body of an apparatus element or between two conjoined apparatus elements which come together to define the pathway as a region of materials removal or omission in one or both of said conjoined apparatus elements.

Atomisation apparatus are thus preferred in which the gas transmission further pathways are each defined in and by a body of the apparatus which also preferably defines the constriction and which is separable from the rest of the apparatus. However, the gas

SUBSTITUTE SHEET (RULE 26) transmission further pathways, more generally, may be formed in the body of an apparatus element or between two conjoined apparatus elements which come together to define the pathway as a region of materials removal or omission in one or both of said conjoined apparatus elements; for example, the pathway may be a channel, in one element or the other, which is closed by the other element to form a conduit or, alternatively, a conduit may be formed between two elements each of which is formed with part of the cross-section of the conduit so that a conduit in whole can be formed by the marriage of the two elements together in such a manner that the two-part cross sections of the conduit become integrated.

In a preferred embodiment of the invention, nozzle assembly is included comprising said nozzle includes a collar perforated by one or a plurality of liquid transmission pathways connecting a chamber for atomisation liquid disposed in the apparatus on the downstream side of the collar, reading from the flow direction of said driving gas stream, with said fluid passageway disposed on the upstream side of the collar, again reading from the flow direction of said driving gas stream, said connection being optionally via an intermediate zone of the apparatus.

At least the gas-contacting surfaces of the means defining said gas transmission pathway are conveniently made of stainless steel.

In a further embodiment, an atomization apparatus in accordance with the invention is one wherein:

(a) a first module comprises a nozzle;

(b) a second module defines said driving gas pathway and a Venturi constriction is provided in said driving gas pathway for receiving said gas stream and outputting it to said atomisation chamber, said fluid passageway and optionally one or more bypass gas streams pathway along which to transmit a bypass gas stream to said fluid passageway, bypassing said Venturi; and

(c) said first and second modules together define said fluid passageway as a separation between a surface of one of said first and second modules and an opposed surface of the other.

SUBSTITUTE SHEET (RULE 26) The housing is preferably fixed to the male component of a bayonet assembly for mounting the atomisation apparatus by marrying the male component of the bayonet assembly to a female component thereof. Means is preferably provided in the male component of the bayonet assembly respectively for supplying gas and atomisation liquid to the apparatus.

A female component of a bayonet assembly is conveniently mounted to a mounting platform for the apparatus and the male component of the same bayonet assembly is received within the female component and removably fixed in position. Preferably, passageways are provided in the female component of the bayonet assembly respectively for connecting gas and atomisation liquid supplies to gas and liquid passageways which this are provided in the male component of the bayonet assembly.

In a preferred atomisation apparatus according to the invention, a first body has a liquid receiver for receiving said liquid material for supply to said fluid passageway and a gas receiver for receiving said gas which is supplied to the apparatus; a second body is mounted to said first body; and a third body is also provided; said second and third bodies together, or said first, second and third bodies together, defining a liquid passageway for connecting said liquid receiver, and a gas passageway for connecting said gas receiver, at respective liquid and gas inlet orifices of said liquid and gas passageways, respectively, to a source external to the apparatus of said liquid material and a source external to the apparatus of said gaseous material: said second and said third bodies together forming a bayonet-and-socket assembly in which one of them comprises a bayonet sub-assembly and the other of them comprises a socket sub-assembly, the bayonet of the bayonet sub-assembly being alternately receivable in the socket of said socket sub-assembly and withdrawable therefrom, both the bayonet sub-assembly and the socket sub-assembly defining a part of each of said liquid and gas passageways,

SUBSTITUTE SHEET (RULE 26) said bayonet-and-socket assembly having: a first condition of assembly in which the bayonet of said bayonet sub-assembly is fixed in the socket of said socket sub-assembly to prevent the second and third bodies being separated one from the other and in which first condition said gas and liquid passageways are open for passage of gas and liquid, respectively, from said gas and liquid inlet orifices to said gas and liquid receivers, and a second condition of assembly of said bayonet-and-socket assembly in which the second and third bodies are separable one from the other, and said bayonet-and-socket assembly being: manipulable, whilst the bayonet of said bayonet sub-assembly remains disposed in the socket of said socket sub-assembly, to change the condition of said bayonet-and-socket assembly between said first and second conditions thereof.

SUBSTITUTE SHEET (RULE 26) DESCRIPTION OF PREFERRED EMBODIMENTS

A preferred embodiment of the Venturi device and the atomization apparatus of the invention will now be described, by way of example only, reference being made to the accompanying drawings in which:

Figure 1 is a simple schematic outline of the preferred embodiment showing the atomization apparatus broken down into the four main sections 100 - 400 of which it is comprised and with the gas-liquid mixing assembly thereof itself broken down into its component five sections;

Figure 2 is a further schematic outline, in this case directed with greater particularity to the composition of each of the component five sections which make up the gas-liquid mixing assembly, as well as their-relationships, the gas and liquid supplies for the apparatus being indicated schematically in order to provide full context;

Figure 3 is a view from one side of the atomisation apparatus, the Figure showing each of the four main sections of the apparatus as they appear in the apparatus assembled ready for use, each main section being indicated in positional approximation by a reference numeral denoting that section;

Figure 4 is a three quarter view from slightly above of the atomisation apparatus shown in Figure 3 as seen from the downstream end of the atomiser housing assembly 100, with each main section similarly designated;

Figure 5 is a three quarter view from slightly above of the atomisation apparatus shown in Figure 3 as seen from the upstream end of the atomiser housing assembly 100 (ie the motor end);

Figure 6 is a downstream end view of the apparatus shown in Figures 3 to 5 (ie the nozzle outlet end);

Figure 7 is an upstream end view of the apparatus shown in Figures 3 to 6 (i.e. the motor end);

Figure 8 is a plan view of the apparatus shown in Figures 3 to 7;

SUBSTITUTE SHEET (RULE 26) Figure 9 is a detail showing on a larger scale the part of the apparatus shown in Figure 8 indicated by the viewport IX therein;

Figure 10 is a cross-section of the atomisation apparatus shown in Figures 3 to 8 taken on the line X - X of Figure 8;

Figure 11 is an exploded view of the atomiser housing assembly 100 identified in general terms in Figures 3 and 4, the Figure showing each of the component five sections which make up the gas-liquid mixing assembly 500 - 900 interspersed with components of the atomiser housing assembly in which they are housed;

Figure 12 is an exploded view of the overall mounting and supply assembly 200, 300, 400 shown schematically in Figure 1;

Figure 13 is a cross-section through the atomisation apparatus shown in Figures 3 to 7 taken on the line XIII - XIII of Figure 6 and showing details of all the sections of the apparatus shown schematically in Figures 1 and 2:

Figure 14 shows a portion of the apparatus cross-section shown in Figure 13 but on an enlarged scale;

Figure 15 is a cross-section of the atomisation apparatus shown in Figures 3 to 7 taken on the line XV - XV of Figure 13 and showing in particular the atomisation liquid and gas services provided in sections 200, 300 and 400 of the apparatus for supply of those materials to the gas-liquid mixing assembly 500-900;

Figure 16 is a view of the atomisation apparatus shown in Figures 3 to 7, and in Figure 4 in particular, but inverted relative to that Figure as if it is to be fitted at a high level to a vertical surface such as a wall, the Figure showing in particular the under-surface of the platform and manifold assembly 400 shown in Figures 3 to 7;

Figure 17 shows various views of the bayonet assembly 200 referred to schematically in Figure 1 and shown in cross-sectional detail in Figures 13 and 15, as follows:

Figure 17A is a perspective view of the bayonet assembly 200, the Figure to be viewed together with Figures 12 to 15 in particular, intended to contribute an

SUBSTITUTE SHEET (RULE 26) understanding of the liquid and gas circuits for supply of those materials to the gasliquid mixing assembly 500-900;

Figure 17B is a perspective view of the bayonet assembly 200, as shown in Figure 17A but turned clockwise through an angle of about 45°;

Figure 17C is a perspective view of the bayonet assembly 200, as shown in Figure 17A but turned counter-clockwise through an angle of about 45°; and

Figure 17D shows the platform and manifold assembly 400 as an x-ray view exposing the internal ducting systems for the gas and liquid supply shown in less detail in Figures 13 and 15;

Figure 18 is a perspective side view of the gas-liquid mixing assembly 500 - 900 of the atomisation apparatus turned slightly clockwise in order better to show certain details of the assembly seen from a slightly upstream perspective;

Figure 19 is a detail showing on a larger scale the part of the apparatus shown in Figure 18 within the viewport XIX;

Figure 20 is a perspective side view of the gas-liquid mixing assembly 500 - 900 of the atomisation apparatus, this view being similar to that shown in Figure 19 but with the gasliquid mixing assembly turned slightly counter-clockwise in order better to show certain other details of the assembly seen from a slightly downstream perspective;

Figure 21 is a detail shown on a larger scale the part of the apparatus shown in Figure 21 within the viewport XXI;

Figure 22 is an exploded view showing an upstream part of the gas-liquid mixing assembly 500 - 900 shown in Figure 18, and from a similar visual perspective to that Figure; Figure 22 is on a slightly larger scale as compared to Figure 18 and shows several component parts not shown in Figures 18 and 19 (in certain cases, primarily in the interests of reader orientation) whilst, for simplicity and clarity of depiction, the mounting assembly 117 (Figures 11 and 26) for electric motor housing 115 is omitted from Figure 22;

SUBSTITUTE SHEET (RULE 26) Figure 23 shows a downstream section of the gas-liquid mixing assembly 500 - 900 shown in Figure 20 (constituting essentially the Venturi module M referred to in Figure 1) housed within the two-part shell housing 101 shown in Figures 3 to 7 , the housing and part of the internal structure being cut back to present a partial cross-section;

Figure 24 is a partial cross-section of the gas-liquid mixing assembly 500 - 900 shown in Figure 20, the same (internal) parts cut back as in the case of Figure 23;

Figure 25 is a partial cross-section of the major portion of the gas-liquid mixing assembly 500 - 900 as shown in Figure 24, the two Figures differing in that the nozzle assembly shown in Figure 24 has been removed from the downstream end of the gas-liquid mixing assembly to expose the Venturi output cone;

Figure 26 is a cross-section on the line XXVI-XXVI of Figure 17C, the section being on a similar scale to Figure 14, Figure 17C showing substantially the whole of the gas-liquid mixing assembly but only an uppermost portion of the bayonet mounting assembly 200, 300;

Figure 27 is a detail on a larger scale the part of the apparatus shown in Figure 26 within the viewport XXVII showing the intersection of the various fluid passageways in the gasliquid mixing assembly and further showing part of the nozzle assembly 902;

Figure 28 is a perspective view the complete nozzle assembly 902 shown in part in Figure 27;

Figure 29 shows in two separate views details on a larger scale of the part of the apparatus shown in Figure 27 within the viewport XXIX therein, as follows:

Figure 29A shows the above part with the gap 725 near to its maximum; and

Figure 29B shows the above part with the gap 725 at the minimum size normally adopted in practice for common liquid materials (e.g. water);

Figure 30 is a cross-section through the main shell housing 101 taken on the line XXX -XXX of Figure 29B);

SUBSTITUTE SHEET (RULE 26) Figure 31 shows form and dimension in relation to certain components of the Venturi module M identified in Figure 11 and illustrates gas flow and liquid droplet development, as follows:

Figure 31A is a cross-section through the Venturi module M serving to indicate certain dimensional relationships relevant to driving gas flow;

Figure 31B shows the conduit tapering of the conduit 721 shown in the viewport XXXIB of Figure 31A, Figure 31B showing the conduit in the same longitudinal section as, but on a larger scale than in, Figure 31A;

Figure 31C shows fluid flow paths as a simple diagram to be seen in conjunction with Figure 31D below; and

Figure 31D shows the conjunction of the fluid passageways in relation to the apparatus nozzle and illustrates liquid film flow and its transformation in a process of atomization to form, when exposed to sonic output from the Venturi 715, configurationally unstable ligaments which then convert to liquid droplets;

Figure 32 shows conduit cross-sections at the conduit ends as follows:

Figure 32A is a section on the line XXXIIA of Figure 31A-which approximates an end view of the Venturi module M as seen from its upstream end (ie the location of the conduit inlet orifices);

Figure 32B shows on a larger scale the profile of the inlet orifice shown in the viewport XXXI I B shown in Figure 32A;

Figure 32C shows an end view of the Venturi module M from the direction of the arrow XXXI IC in Figure 31A (ie as seen from its downstream end, the location of the conduit outlet orifices); and

Figure 32D shows on a larger scale the profile of the outlet orifice shown in the viewport XXXIID shown in Figure 32C;

SUBSTITUTE SHEET (RULE 26) Figure 33 is a schematic flow diagram showing diagrammatically an integrated atomisation system, including the atomisation apparatus of the invention completely assembled for use;

Figures 34 shows geometry and boundary conditions for a computational fluid dynamics (CFD) model which was used to conduct a CFD investigation in relation to the atomisation apparatus 1 as compared to the same apparatus equipped with conventional (although longitudinally tapered) conduits CC as opposed to conduits 721; in the interests of simplicity, Figure 34 shows the conduits in indicative form only with, fictionally, no configurational of difference shown between conduits CC and conduits 721;

Figures 35 to 45 show diagrammatically the fluid velocity findings of the CFD investigation mentioned above performed on fluid flows in two different regions of the atomisation apparatus 1, namely:

• in the gas conduits (i.e. gas conduits CC of conventional circular cross-section form and longitudinally tapered or gas conduits 721); and

• in the gas-liquid receiving and transit passageway (second pre-mixing region) PM2 fed with gas flow from, respectively, conduits CC or 721 (via the first pre-mixing region PM1):

Figure 35:

Figure 35A shows in colour findings for fluid velocity in a conventional conduit CC;

Figure 35B shows in colour findings forfluid velocity in a conduit 721 (which is referred to in various earlier Figures); and

Figure 35C shows as a detail, in colour and on an enlarged scale, the portion of Figure 35A indicated therein by the arrow XXXVC;

Figure 35D identifies the interrogation plane relevant to Figures 35A and 35B;

Figure 36:

SUBSTITUTE SHEET (RULE 26) Figure 36A shows in colour the findings of Figure 35A on a larger still scale, the chamber 706 (Figure 34) somewhat cut back in order to make economic use of paper; and

Figure 36B shows in colour the findings of Figure 35B, on a larger scale than in the latter Figure, with chamber 706 cut back in similar fashion to Figure 36A;

Figure 37:

Figure 37A shows in colour the CFD findings for the gas flow in annular gasliquid receiving and transit passageway (second pre-mixing region) PM2 fed with gas flow from the conventional conduit shown in Figure 35A, Figure 37A showing an arc of approximately 6°;

Figure 37B shows in colour the CFD findings for the gas flow in annular gasliquid receiving and transit passageway (second pre-mixing region) PM2 fed with gas flow from the conduit 721 shown in Figure 35B, Figure 37B again showing an arc of approximately 6°;

Figure 37B2 shows as an enlarged scale detail the portion shown in Figure 37B in the view port XXXVIIB; and

Figure 37C identifies the interrogation plane relevant to Figures 37A and 37B (it may assist to consider Figures 27 and 28 at the same time);

Figure 38:

Figure 38A shows in colour the CFD findings of Figure 37A on an enlarged scale and limited to the boundary region XXXVIIIA identified in Figure 37A; and

Figure 38B shows in colour the CFD findings of Figure 37B on an enlarged scale and limited to the boundary region XXXVI I IB identified in Figure 37B;

Figure 39

SUBSTITUTE SHEET (RULE 26) Figure 39A is a monochrome version of Figure 35A;

Figure 39B is a monochrome version of Figure 35B;

Figure 39C is a monochrome version of Figure 35C; and

Figure 39D is a monochrome version of Figure 35D;

Figure 40:

Figure 40A is a monochrome version of Figure 36A; and

Figure 40B is a monochrome version of Figure 36B;

Figure 41:

Figure 41A is a monochrome version Figure 37 A; and

Figure 41B is a monochrome version of Figure 37B;

Figure 42:

Figure 42A is a generally monochrome version of Figure 38A, the detail shown at the top right being an extracted portion from Figure 38A; and

Figure 42B is a generally monochrome version of Figure 38B the detail shown to the left of the Figure being an extracted portion from Figure 38A;

Figure 43:

Figure 43A is a further (although simplified) monochrome version of Figure 36A which, however, shows the conventional conduit shown in Figure 36A overlaid with a series of five sections (which are numbered I to V) noted thereon, each of which is slightly overlapping with its adjacent sections, the individual sections being depicted on an enlarged scale in Figure 43D below;

Figure 43B is a further (although simplified) monochrome version of Figure 36B which, however, shows the conduit 721 shown in Figure 36B overlaid

SUBSTITUTE SHEET (RULE 26) with a series of five sections (which are numbered I to V) noted thereon, each of which is slightly overlapping with its adjacent sections, the individual sections being depicted on an enlarged scale in Figure 43E below;

Figure 43C shows, on an enlarged scale, the region indicated in Figure 43A within the circle XXXXIIIC, the better to see the longitudinal velocity profile of the conduit CC gas as it leaves the plenum space (see Figure 34, reference numeral 706; Figure 26, reference numerals 713/706; and Figure 27, reference numeral 706) from which it is supplied;

Figure 43D shows, in a series of separate Figures, each on a scale of about X5, the sections I to V depicted in Figure 43A annotated with U values applied to various velocity domains; and

Figure 43E shows, in a series of separate Figures, each on a scale of about X5, the sections I to V depicted in Figure 43B annotated with U values applied to various velocity domains;

Figure 44 is a graph which plots the gas velocity of the gas film against location on the respective arcs A-A and B-B shown in Figures 38A and 38B, respectively; and

Figure 45 is a graph which plots gas velocity of the film shown in Figures 38A and 38B against normalised distribution.

A. OVERVIEW

As shown in Figure 1, the preferred embodiment of atomisation apparatus according to the invention comprises three principal component assemblies: an atomizer housing assembly 100, together with a bayonet-and-socket assembly 200, 300 comprising a male component in the form of a bayonet assembly 200 and a female component in the form of a socket assembly 300, and a platform and manifold assembly 400.

The bayonet-and-socket assembly 200, 300 together with platform and manifold assembly 400 constitute in combination an overall mounting and supply assembly for a gas-liquid

SUBSTITUTE SHEET (RULE 26) mixing assembly composed of several physically distinct sections 500, 600, 700, 800 and 900 housed within the atomiser housing assembly 100.

In its setting as deployed, the apparatus forms a part of an integrated environmental system 20 (Figure 33) including components for supply of gas and liquid materials together with components having various control functions.

The atomizer housing assembly 100 is a series of housing assembly sections 102, 103, 107 and 108, section 108 having upstream housing portions thereof 114 and 122 as well as the main downstream portion thereof, whose collective purpose, as shown in detail in Figure 11 of the drawings, is principally to house the sections 500, 600, 700, 800 and 900 of the gas-liquid mixing assembly mentioned above.

Bayonet assembly 200, the male component of a bayonet-and-socket assembly shown in Figures 3 and 4 also comprises a socket assembly 300 (referred to below). By means of the overall bayonet-and-socket assembly 200, 300, the atomiser housing assembly is mounted for use. As shown in Figures 13 and 15, the bayonet assembly 200 is provided with internal passageways for separately delivering atomisation gas and liquid to be atomised to the appropriate region of the gas-liquid mixing assembly.

Socket assembly 300 is, as shown in Figures 3 and 4, the female component of the bayonet- and-socket assembly 200, 300. This is also provided with internal passageways (Figures 13 and 15) for separately delivering, via the bayonet assembly 200, atomisation gas and liquid to be atomised to the appropriate region of the bayonet assembly 200.

Platform and manifold assembly 400 (Figures 3 and 4) is a mounting and supply platform for mounting the male and female bayonet assemblies 200 and 300. As shown in Figures 13 and 15, when so mounted, the previously mentioned internal passageways of the bayonet assembly 200 are then in communication with the gas/liquid supply lines of the platform and manifold assembly 400 in order to supply the gas-liquid mixing assembly 500 - 900 with atomisation gas and liquid to be atomised.

Platform and manifold assembly 400 will itself in practice be mounted to a further substrate; for example, platform and manifold assembly 400 may be mounted to a fixed

SUBSTITUTE SHEET (RULE 26) surface such as a wall of a building or to a vehicle such as a trolley. More generally, the atomisation apparatus according to the invention may be in a form for use as a fixed installation in a building or fixed at another site which might, for example, be an external open-air site, in an underground structure or in a ship. Fixed installations will, of course, in many cases make use of an existing infrastructure of e.g. pipework and electrical power with the atomisation apparatus of the invention installed in retro-fit fashion; however, in capital expenditure terms, it is expected that de novo installations would in many cases the less expensive. Alternatively, of course, the atomisation apparatus of the invention may be configured as a mobile unit which would generally be mounted to a vehicle, for example a trolley, truck or trailer. Mobile systems will generally be entirely self-contained and completely portable to enable treatment at application sites where, as is quite common, access is limited; pressurised gas would be provided in containerised form, adequate supplies being carried along with the atomisation apparatus upon vehicles used for transportation of the latter. When fixed to a vehicle such as a trolley, platform and manifold assembly 400 may be fluid ically coupled to a hand-held frame via an extendable hose, the frame being provided with a trigger operable to toggle the gas and liquid flow of the apparatus between ON and OFF conditions.

Referring to the gas-liquid mixing assembly 500-900, the sections which make up its overall structure define amoungst them various functional zones within atomizer housing assembly 100, each zone differentiated by the particular process step of the overall atomization and plume delivery processes which take place in that zone. As noted earlier, the zonal arrangement in the gas-liquid mixing assembly 500 - 900 is set out in Figure 2, each zone being referenced in that Figure to the gas-liquid assembly section and the section of the atomiser housing assembly 100 which supports the function for which the zone is responsible.

Apparatus as shown in the accompanying drawings can (and, indeed, the apparatus of the invention in general), of course, be constructed on a variety of scales according to the desired performance of the atomizer. In the preferred embodiment of atomisation apparatus according to the invention, as shown in the accompanying drawings, the design performance is as follows:

SUBSTITUTE SHEET (RULE 26) Maximum gas pressure (air): 4.5 bar (450kPa)

Maximum liquid pressure: 4.5 bar (450kPa)

Gas throughput volume ¹ 833 litres per minute Liquid throughput volume ² 0.05 litre per minute liquid viscosity range tested 1 - 150 mPa-s

1. Max at stated max gas pressure

2. Max at stated max liquid pressure

In view of the intricately detailed structures involved, referencing of individual components in the drawings is not necessarily complete upon each and every Figure, whilst nevertheless being complete across the drawings as a set.

Apparatus of the kind the subject of the invention involves complex considerations of fluid dynamics. In order to give insight into the performance of the apparatus 1 shown in the accompanying drawings, with particular reference to the fluid dynamics of the system of passageways used to transfer fluids from one apparatus location to another, the applicant has had carried out a computational fluid dynamics (CFD) investigation addressing aerodynamics in conduits 721 (see Figures 23 to 27, 31 and 32 in particular for the participation of this component in operation of apparatus 1) and in the second pre-mixing zone PM2 (see Figures 23 and 29 in particular). The CFD investigation compared the conduits 721 with a conventional conduit CC (see Figure 34) having a circular cross-section throughout, which was also tapered longitudinally in the downstream direction.

The CFD investigation was conducted according to the following protocols: -

1. The CFD models were run as steady-state compressible three-dimensional RANS flow solutions.

2. A Sutherland viscosity model was applied.

3. Ideal gas flow was applied.

4. A k-u) SST Turbulence model was applied.

5. The CFD models were run as single phase air models (no liquid atomisation was included in running the models).

6. Pseudo steady-state analysis was assumed.

SUBSTITUTE SHEET (RULE 26) CFD models were run to the following parameters and conditions:

1. Three-conduit sector model.

2. Internal gas-contacting surfaces were assumed to be non-slip.

3. Mass transfer through three conduits was 9.387e~ ⁴ (3x3.129e~ ⁴ per conduit) kilograms per second (based on a full model circular cross-section conduit flow rate).

4. Pressure at the outlet of the second pre-mixing zone PM2 was P=393.45kPa [3.88 bar] (based on full model throat pressure).

5. Cyclic symmetry assumed (see Figure 34)

6. Interrogation planes through the second pre-mixing zone PM2 were upstream of liquid introduction through orifices 807 (see Figure 28 in particular for these orifices).

7. Ambient temperature = 293K.

B. ATOMIZER HOUSING AND MOUNTING AND SUPPLY ASSEMBLY

ATOMIZER HOUSING ASSEMBLY 100

The overall atomiser housing assembly is comprised of housing components 102, 103, 107 and 108, as noted above. These will be described as such, with the gas-liquid mixing assembly 500 - 900 described after component assemblies 100, 200, 300 and 400 in order that that further description can be provided in full context.

Referring first to the atomiser housing assembly 100, this assembly is shown in Figures 3 to 7 (external views) as well as Figures 11 (exploded view), 13 and 26 (cross-sectional views).

Atomiser housing assembly 100 comprises a main shell casing or housing 101 which houses the gas and liquid zones of the gas-liquid mixing assembly (which will be described hereinafter). The atomiser assembly 100 comprises an anterior (or downstream) half-shell 102 and a posterior (or upstream) half-shell 103. In the assembled apparatus assembly 100, half-shells 102, 103 correspond, respectively, to the liquid zone and the gas zone previously referred to; as will be described hereinafter, these two key zones of the

SUBSTITUTE SHEET (RULE 26) atomisation apparatus according to the invention are referred to in the context of Figure 11, respectively, as Zone 500 and Zone 600. As shown in Figures 3 to 5, the half-shells 102, 103 are unified, by three bolts 104 (Figure 5) each passing through a boss 105 in halfshells 103 and received in a boss 106 of half-shell 102.

Half-shell 103 has an upstream section 107 of smaller and reducing cross-section which it will be seen from Figures 3 to 7 as well as Figures 11, 23 and 26 is mounted to a further housing section 107, the two being unified in a manner similar to the unification of halfshells 101, 102, namely by means of bolts 109 (Figures 5 and 7) together with boss 110 and boss 111. The wall of housing section 107 is perforated to receive therethrough a cable 124 which is provided to supply electrical power for the electrical motor 501 described hereinafter and for a controller 612 provided within the housing section 108 to control the gas-liquid mixing assembly, the controller 612 being shown schematically in Figure 33.

Upstream from its union with housing section 107, the previously mentioned section 122 of housing section 108 of reducing cross-section is integral with the housing portion 114 of housing section 108 (Figure 11). Bosses 112 are provided at this location which, together with bosses 113 of electrical motor housing 115 serve to receive fastening bolts 116 (Figures 5, 7 and 11) to fix the electrical motor housing 115 to the housing portion 114 of housing section 108.

Downstream of housing portion 114 in the assembled condition of the atomiser housing assembly 100, mounting assembly 117 of the electrical motor housing 115 is of crosssection larger than, although reducing in the direction of, the main body of the electrical motor housing 115. Mounting assembly 117 defines a shallow internal chamber, as will be seen from Figure 26 and can also be appreciated from Figure 11, in order that it also serves the function of a housing.

Main shell housing 101 is provided on its underside (referring to the orientation shown in Figure 6 of the drawings) with a foot portion 121 (Figures 14, 15, 26 and 30) provided with ports 119 and 120 by means of which atomisation gas and liquid to be atomised are, respectively, supplied to the previously mentioned gas and liquid zones, Zones 600 and 500 (Figure 11), of an atomiser device housed within atomiser housing assembly 100.

SUBSTITUTE SHEET (RULE 26) For the purpose of fixture of main shell housing 101 to the bayonet assembly 200 described below, each of half shells 102 and 103 is provided with a boss 118 at each of its opposed sides for receiving bolts 215, as described in more detail in the next section below, the four bosses 118 being arranged about and externally of the foot portion 121, as best seen from Figure 30.

All of housing components 102, 103, 107 and 108 are made of 316L stainless steel formed by casting or liquid metal injection moulding, with internal configuration produced by CNC machining.

Internally, the housing components referred to above will have a particular configuration determined by the housed components, and this will be explained in more detail hereinafter when describing the gas-liquid mixing assembly.

BAYONET ASSEMBLY 200

The bayonet assembly, or male assembly, 200 of the bayonet-and-socket assembly 200, 300 (Figures 12 to 15) is mounted to the underside of shell housing 101 by means of connection plate 208 which is integrally cast with the remainder of the bayonet assembly 200, namely upper cylindrical part 206 and lower cylindrical part 207 of smaller crosssection. Fixture between the bayonet assembly 200 and the underside of shell housing 101 is by bolts 215 (Figures 4, 7 and 30) passing through bosses 216 (Figures 4, 12 and 17) of the connection plate 208 and bosses 118 (Figures 2 and 23) formed on the underside of the half-shells 102, 103 of main shell housing 101. Connection plate 208 is formed with a well 203 as shown in Figure 12 where it will be seen that bosses 216 are arranged about and externally of the well.

When bayonet assembly 200 is mounted to the main shell housing 101 in the above manner, previously mentioned ports 119, 120 of the main shell housing 101 connect for fluidically secure connection, respectively, with air feed port 202 and liquid feed port 201 of bayonet assembly 200. The air feed port 202 and liquid feed port 201 can best be seen in Figures 12 to 15 in Figure 26, and it will be seen from Figure 12 that they are positioned in well 203 of bayonet assembly 200. It will be noted by reference to Figures 14 and 26 that the previously mentioned foot portion 121 of main housing 101 is seated within the

SUBSTITUTE SHEET (RULE 26) well 203 in the assembled condition of the atomisation apparatus. The foot 121 and its seat in well 203 serve to enable location of the atomiser assembly 100 to the male bayonet mounting 200, for example, when the atomiser assembly 100 has been separated from the bayonet assembly 200 for servicing of one or the other and needs to be replaced. Ports 201 and 202 serve air feed conduit 205 and liquid feed conduit 204, respectively (Figures 14, 15 and 26).

As shown in Figures 13, 15 and 17, both cylindrical parts 206, 207 are, respectively, formed with four circumferential gas supply ports 209 (upper port) and 210 (lower port), which are bored through the cylindrical wall in each case at circumferentially equally-spaced locations. Ports 209, 210 are respectively provided at the base of shallow circumferential air communication grooves 212,213 (Figures 15 and 17C) respectively formed in the outer cylindrical surface of the upper cylindrical part 206 and lower cylindrical part 207 of bayonet assembly 200. Upper groove 212 and lower groove 213 are so-designated in Figures 15, 14 and 16 but shown most clearly in Figure 17. Gas supply to port 209 is fluidical ly isolated at the interface of the male and female bayonet assemblies 200 and 300 shown in Figurel3 by annular rubber seals 209A and 209B; in similar fashion, liquid supply to ports 210 is fluid ically isolated by annular rubber seals 210A and 210B.

Complementary gas and liquid supply services in the socket assembly 300 are described hereinafter with reference to Figures 7 and 9.

A pair of spigots 211 (Figures 12 and 17) are provided one at each of diametrically opposed locations in the cylindrical wall of upper cylindrical part 206 of bayonet assembly 200. When the male and female bayonet assemblies 200 and 300 are assembled together, each of the spigots 211 engages in a key 301 of the socket assembly 300. A spring loading mechanism 214 (not shown as such but merely by its location) provides the axial tension required for firm engagement of the bayonet assembly 200 within the socket assembly 300 and also for ease of withdrawal of the former from the latter.

Except where stated otherwise, all components of bayonet assembly 200 are made of 316L stainless steel and formed by casting or liquid metal injection moulding, with all sealing surfaces finished by CNC machining. All seals are polymer seals.

SUBSTITUTE SHEET (RULE 26) SOCKET ASSEMBLY 300

Turning to the socket assembly, or female assembly, 300 of the bayonet-and-socket assembly 200, 300, it will be seen from Figures 4 and 5 in particular that this comprises a cylindrical base member 302 which is mounted to and integral with the mounting plate 303. The mounting plate 303 is in turn mounted to a corresponding mounting plate 401 fixed to the platform 400 as will be described hereinafter. Integral with cylindrical base member 302 is an upper cylindrical member 306 which is provided with a circular aperture 317 (Figure 12) at its top for receiving the bayonet assembly 200.

As shown in Figure 13, extending adjacent the periphery of cylindrical base member 302, is a pair of gas conduits 309, 310 which extend longitudinally through the body of the cylindrical base member 302 parallel to its axis from the base of socket assembly 300, and into the upper cylindrical member 306 to a point just short of the transition between cylindrical base member 302 and upper cylindrical member 306 . Each of gas conduits 309 and 310 has a cross-section which is uniform through its length and, for efficiency of gas flow, the cross-section is kidney-shaped. At the same diametrically opposed locations, the cylindrical base member 302 is provided with a pair of cross-bores which are in communication with conduits 309, 310 respectively. Cross-bores 311 feed air radially inwardly to the previously-mentioned circumferential groove 212 in the upper cylindrical part 206 of bayonet assembly 200. Referring in particular to Figures 3 to 7 and Figure 12, flanges 307 (Figures 3 to 5) upstanding from cylindrical base member 302 are provided at diametrically opposed locations thereof and receive removable fluid plugs 308Ain its air ports 308.

As shown in Figure 15, the cylindrical base member 302 is further provided at diametrically opposed locations with respect to one another with a pair of liquid conduits 312, 313 which each extend longitudinally from the bottom of the cylindrical base member 302 parallel to its axis to a point adjacent one of a pair of diametrically opposed bosses 305 which will be further mentioned hereinafter. For efficiency of gas flow, conduits 312 and 313 have kidney-shaped cross-sections, as in the case of conduits 309, 310. As in the case of conduits 309 and 310, each of conduits 312 and 313 has a cross-section which is uniform through its length.

SUBSTITUTE SHEET (RULE 26) Seen in plan, it will be appreciated that gas/liquid conduits 309, 310, 312 and 313 are spaced apart at 90° intervals on a virtual circle concentric with the cylinder body of the socket assembly component 300.

At each of the same diametrically opposed locations as the liquid conduits 312, 313, a cross-bore 314 is provided. Each cross-bore 314 is in communication with one of the liquid conduits 312, 313 and is arranged to feed liquid radially inwardly to the previously- mentioned circumferential groove 213 in the lower cylindrical part 207 of the bayonet assembly 200. Previously mentioned bosses 305 upstanding from the mounting plate 303 at the locus of those same diametrically opposed locations each define a port 304 which communicates with the liquid-carrying cross-bore 314 just mentioned; a plug 304A is received in each port for liquid containment purposes.

As shown, for example, in Figures 4 and 12, the upper cylindrical member 306 is instrumental in executing the bayonet fixing and release functions between the bayonet assembly 200 and the socket assembly 300. To this end, the cylindrical wall of the cylindrical upper member 306 is formed with a key slot 315 at diametrically opposed locations each for receiving one of the spigots 211 referred to earlier. As shown, for example, in Figure 4, each key slot 315 is associated with an arcuate pathway 316. Each arcuate pathway 316 perforates the cylindrical wall of the upper cylindrical member 306 and has its mouth in the upwardly facing annular surface 318 of that component surrounding the opening 317.

When it is desired to marry the bayonet and socket assemblies 200 and 300, the bayonet assembly 200 is manually offered up to the opening 317 at the top of the upper cylindrical member 306 of the socket assembly 300 (Figure 12). The diametrically opposed spigots 211 are then manually located in the mouths of the respective arcuate pathways 316. The bayonet assembly 200 is next rotated manually in a clockwise direction whereby the spigots 211 follow the arcuate pathway 316 until each engages in its respective key slot 315 and the bayonet assembly 200 has at the same time been displaced further into the socket assembly 300. At this point, the base of the bayonet assembly 200 will have been brought into engagement with the spring loading mechanism 214 (Figures 13 and 15). The latter exerts upon the bayonet assembly 200 an axially upward force. Accordingly, once

SUBSTITUTE SHEET (RULE 26) manual control of the bayonet assembly 200 is released, the spigots 211 rise in the respective key slots 315, lodge in the upper section thereof and remain engaged there until released by once again applying downward axial pressure on the bayonet assembly 300 until the spigots 211 can be re-entered into the arcuate pathway 316 and the bayonet components thereby separated.

Except where stated otherwise, all components of socket assembly 300 are made of 316L stainless steel and formed by casting or liquid metal injection moulding with all sealing surfaces finished by CNC machining. All seals are polymer seals.

PLATFORM AND MANIFOLD ASSEMBLY 400

Referring to the platform and manifold assembly 400 and to Figures 3 to 7, 12 and 16, a 316L stainless steel base mounting plate 401 is integral with planar upper surface 402 of base manifold 406 also made of 316L stainless steel, which is upwardly-facing in the orientation depicted in Figures 3 to 7 but downwardly facing in the orientation shown in Figure 16 (which latter will be referred to hereinafter). As noted previously, the lower cylindrical member 302 of socket assembly 300 is mounted to the base mounting plate 401 by the mounting plate 303 of lower cylindrical member 302. Bolts 403 secure the two mounting plates together, passing through bosses 319 of mounting plate 303 (Figure 4) and being received threadedly in bosses 416 of base mounting plate 401.

The base manifold 406 is mounted to the support tray indicated generally by reference numeral 417 in Figures 4 and 12 and made of 316L stainless steel. The base manifold 406 is supported on the internal floor surface 421 of support tray 417 where it is partially enclosed by end wall 418 and side walls 419 and 420, the latter of which is shown in Figures 5 and 12.

As shown in Figure 12, the internal floor surface 421 of support tray 417 is provided with openings 422 by means of which tray 417 can be secured from its underside to the base manifold 406.

Solenoid valves 404 (gas) and 405 (liquid) are mounted to the upwardly-facing surface 402 of base manifold 406 (Figure 4). It will be noted from Figures 12 and 16 that the internal

SUBSTITUTE SHEET (RULE 26) floor surface 421 of support tray 417 is not coextensive with the length of sides 419, 420, the floor panel being provided with an aperture 423 which it will be appreciated facilitates the direct mounting of solenoid valves 404, 405 to the base manifold 406 surface.

Diaphragm-type solenoid valves 404 and 405 are connected to downstream supply services respectively for atomising gas and atomisation liquid supplied thereto for respective distribution to the corresponding services provided in the bayonet assembly 200, 300 as described below. Respective systems of ducting are formed for this purpose by drilling or spark erosion in the body of manifold 406. The foregoing services are conveniently seen in Figures 13 and 15, with the ducting formed in the body of base manifold 406 being shown in detail in Figure 17D. It will be appreciated that drilling or spark erosion to provide conduits in the body of base manifold 406 leads to perforations in the external surface thereof which are redundant and which are required to be blanked off by plugs. Accordingly, blanking-off plugs are provided blanking off otherwise open perforations, two such plugs 404C and 405C for perforations in the end face of the base manifold 406 which faces wall 418 of the support tray 417 being shown in Figure 7 (where they are in place) and in Figure 12 (where they are separated from their destinations in the context of the exploded view there shown.

The gas and liquid ducting in the base manifold 406 is shown in greatest detail in Figure 17D of the drawings, which can be coordinated with Figures 7, 13 and 15.

Referring first to the matter of gas supply to the atomizer, Figures 13 and 17D show an atomisation gas supply to the atomiser device gas zone, section 600, provided via gas conduits 407 and 408 in the body of the manifold base 406. Conduits 407 and 408 communicate at their upper ends, respectively, with conduits 309 and 310 formed in the body of socket assembly 300 and at their lower ends with conduit 409A in the body of base manifold 406. It will be noted from Figure 17D that conduit 409A connects to a separate and shorter conduit section 409B, via cross conduit 410.

Seals 407A and 408A are provided at the interface between base manifold 406 and the socket assembly 300 in order fluidically to secure the gas connection between, respectively, gas conduit 407 and gas conduit 309 of the socket assembly 300, on the one

SUBSTITUTE SHEET (RULE 26) hand, and gas conduit 408 and gas conduit 310 of the socket assembly 300, on the other hand.

Gas is supplied from gas hose 404A (Figures 4 to 7, 12, 13 and 17D) to the solenoid valve 404 via gas hose connection 404A/404B and upright gas input passageway 424. Referring to Figures 5, 12 and 17D, solenoid valve 404 is seated upon planar upwardly-facing surface 402 of base manifold 406 (Figures 5 and 12) and connected across the ports 424A and 425A (Figure 17D), respectively for gas valve input and gas valve output passageways 424 and 425 (Figure 17D, from which the solenoid valve 404 itself has been omitted in the interests of simplicity). By this means, gas supplied via gas hose 404A enters the gas conduit 409B and thence cross-conduit 410. Cross-conduit 410 in turn passes the input gas from gas conduit 409B to gas conduit 409A and thence to conduits 408 and 407 as shown in Figure 17D. It should be noted that gas hose 404A and gas hose connection 404B are identified in Figure 17D in terms of general position but are not shown as such in that Figure, and that they are not shown in Figure 13.

For the reasons given above in describing in general terms the provision of liquid and gas supply services in the body of base manifold 406, the longer section of gas conduit 409A is blanked off at 409C where it perforates the front end wall of the base manifold 406 indicated in Figures 4, 6, 12, 13, 15 and 17D (although the plug used for this purpose is shown only in the context of the exploded view of Figure 12). Similarly, gas cross conduit 410 is blanked off at its point of intersection at 410A with the side wall of platform base 406 (Figures 5 and 17D, in which, however, the plug itself has been omitted in the interests of simplicity) and the gas conduit 409B is blanked off by plug 404C (Figures 7, 12, 13 and 17D, from which the plug itself has been omitted in the interests of simplicity, except in the case of Figure 12 where it is shown in exploded view) at its point of intersection with the rear end wall of platform 406 proximate the solenoid valves 404, 405.

Each of the gas conduits provided in the base manifold 406 is individually of uniform circular cross-section throughout its length.

Turning to the supply of liquid for atomisation, reference is made to Figures 15 and 17D. As shown in Figure 15, liquid for atomisation is provided via upright liquid conduits 412

SUBSTITUTE SHEET (RULE 26) and 413 formed in the body of base manifold 406, as in the case of the gas conduits referred to earlier, by drilling or by spark erosion. Liquid conduits 412, 413 communicate at their upper ends, respectively, with liquid conduits 312 and 313 formed in the body of socket assembly 300. At the lower end of liquid conduit 413, connection is made to conduit 415B, as shown in Figures 15 and 17D, the latter also provided in the body of base manifold 406. It will be noted from Figure 17D that liquid conduit 415B is a lateral liquid conduit (namely, one which crosses the width of the manifold base 406) which is located beneath the overall bayonet assembly 200, 300. Running at a lesser depth in the base manifold 406 is a longitudinal liquid conduit (namely, one extending longitudinally of the manifold base 406), namely conduit 415A (the lesser depth can be appreciated from the relative depths at which conduits 415A and 415B respectively perforate the rear end wall and the side wall of the base manifold 406). The lower end portion of upright liquid conduit 412 connects, just short of its termination, with conduit 415A, the latter connecting at a slightly lower level to conduit 415B thus sharing liquid supply to the base manifold 406 (Figures 15 and 17D).

Seals 412A and 413A are provided at the interface between base manifold 406 and the socket assembly 300 (Figure 15) in order fluidically to secure the liquid connection between, respectively, liquid conduit 412 of the platform base 406 and liquid conduit 312 of the socket assembly 300, on the one hand, and, on the other hand, liquid conduit 413 of the platform base 406 and liquid conduit 313 of the socket assembly 300.

Liquid is supplied from liquid hose 405A (Figures 4 to 7, 12, 13 and 17D) to the solenoid valve 405 via liquid hose connection 404A/405B and upright liquid input passageway 426. As will be understood from earlier description, solenoid valve 405 is seated upon planar upwardly-facing surface 402 of base manifold 406 (Figures 5 and 12) and connected across the ports 426A and 427A (Figures 12 and 17D), provided respectively for liquid input and output passageways 426 and 427 (Figure 17D, from which the solenoid valve 405 itself has been omitted in the interests of simplicity). By this means, liquid supplied by liquid supply hose 405A is fed by the solenoid valve 405 to valve liquid output passageway 427 and received in conduit 415A, passing thence to liquid conduit 412 and, via conduit 415B, to liquid conduit 413 of the bayonet assembly 300. It should be noted that, whilst liquid hose

SUBSTITUTE SHEET (RULE 26) 405A and liquid hose connection 405B are shown in Figure 13, they are identified in Figure 17D in terms of general position but are not shown as such in that Figure.

For the reasons given above in describing the gas conduits in the body of base manifold 406, liquid conduit 415B shown in Figure 15 and 17D is blanked-off where indicated in those Figures by reference numeral 415C. Liquid conduit 415A is similarly blanked off at 405C where indicated by that reference numeral (Figures 5, 7, 12 and 17D, from which the plug itself has been omitted in the interests of simplicity, except in the case of Figure 12 where it is shown in exploded view) at its point of intersection with the rear end wall of platform 406 proximate the solenoid valves 404, 405.

Each of the liquid conduits in the base manifold 406 is individually of uniform circular crosssection.

C. GAS-LIQUID MIXING ASSEMBLY

INTRODUCTION

As will be appreciated, the foregoing description is principally directed to the externally visible housing components of the atomiser apparatus, as shown in Figures 3 to 7 in particular, and to the internal structures and features (and purposes) of the other components of the mounting and supply assembly, namely bayonet assembly 200, socket assembly 300 and platform and manifold assembly 400. The preferred embodiment will now be described more comprehensively in terms of the internal components which are responsible for the various facets of the atomisation process, namely those making up the gas-liquid mixing assembly 500 - 900.

This gas-liquid mixing assembly is depicted in Figures 18 to 21 and in the sections shown in Figures 13, 14 and 23 to 26; Figure 11 shows that same internal assembly in exploded view form in the context of the externally visible components already described (the latter also shown in exploded view in that Figure). Figure 2 is a schematic showing the relationship between the gas zone 700 (Venturi module M), liquid zone 800, gas-liquid zone 900 and the linear drive module 500, 600 in the gas-liquid mixing assembly; it should be noted that the schematic block analysis of the gas-liquid mixing assembly in that Figure

SUBSTITUTE SHEET (RULE 26) coordinates with the zone designations which in Figure 11 are designated by respective same reference numerals 500, 600, 700, 800 and 900.

MOTOR AND INITIAL TRANSMISSION SECTION 500

At the extreme upstream end of the atomizer housing 100, as noted earlier and as shown in Figure 11, a portion 114 of housing section 108 is provided and has a reduced crosssection and a pair of bosses 112 which are disposed at diametrically opposed locations (Figure 7). Electrical motor housing 115 is provided with the previously mentioned mounting assembly 117 which includes a pair of bosses 113 disposed at diametrically opposed locations which align with bosses 112 of housing section 108 when the electrical motor housing 115 is offered up for mounting and correctly oriented. Bosses 112 and 113 serve to receive fastening bolts 116 to fix the mounting assembly 117 of electrical motor housing 115 to the housing portion 114, as shown in the assembled condition of the atomiser housing assembly 100 depicted in particular in Figure 3. Cylindrical boss 511 shown in Figures 11, 18 and 22 is mounted to the upstream face of plate 504. The cylindrical boss 512 shown in Figure 18 only is also so mounted. Bosses 511 and 512 serves the function of guiding the orientation of plate 504 in relation to the mounting assembly 117 when they are offered up to one another and the components of the manual drive gear assembly 510 (Figure 18) inserted into the chamber of mounting assembly 117.

In the aforementioned assembled condition of atomiser housing assembly 100, it will be appreciated from Figures 3 and 26 that the mounting assembly 117 of the electrical motor housing 115 and housing portion 114 sandwich between them, leaving its rim exposed, the plate 504 which will be described below; at the same time, the other components shown in Figure 11 between mounting assembly 117 and housing portion 114 are housed within housing section 108. The previously mentioned electrical motor 501 housed within housing 115 is a Pittman DC022C1 Brush Commutated DC Electric Motor (a 22mm diameter unit which offers continuous output torques of 0.0056 to 0.0141 Nm) available from AMETEK, Inc. Electric motor 501 is controlled by means of a rotary potentiometer (not shown).

SUBSTITUTE SHEET (RULE 26) A tubular drive spindle 502 extends from electric motor 501 (Figure 26) and mounts a terminal gear 502A (Figure 22). As will be seen from Figure 26, drive spindle 502, and accordingly gear 502A thereof in particular, passes through the central region of mounting plate 504. In so doing, gear 502A protrudes on the centre line of motor 501 into the interior of the epicyclic gearbox indicated generally by reference numeral 602 and receives at the downstream terminal end of gear 502A (Figure 22 ) a spigot 503 of driven plate 601 (Figure 26); the epicyclic gearbox 602 and driven plate 601 will be described below in the description relating to section 600. The downstream end of the terminal gear 502A is not shown in the Figures, being concealed by the planet gears 603A,603B and 603C shown in Figure 22. Its function is described hereinafter. Mounting plate 504 has mounted thereto a shaft 505 upon which is rotationally mounted a toothed wheel 506, the latter being contained within housing portion 117.

Externally of housing portion 114 and housed within the chamber of mounting assembly 117 is a manual drive gear assembly indicated generally by reference numeral 510 (Figures 18 and 22). This assembly includes an external idler gear 507 and its shaft 509. Shaft 509 is mounted for rotation relative to mounting plate 504 and is provided at its axial face remote from mounting plate 504 with a hexagonal recess (Figure 22). As shown in various of the Figures including in particular Figures 3 to 7, 11, 13, 16 and 22, a cranked lever arm 508 has a mechanical hex key at the end of the shorter crank arm thereof, which key can be engaged in the hexagonal recess just mentioned, being shown so engaged in Figure 22 and various others of the Figures. For reader orientation purposes, it should be noted that the mounting position of lever 508, at the location of the mounting assembly 117 of electric motor housing 115, is shown in Figure 26 by arrow 508, although the lever 508 itself is not shown. As will be noted from Figure 28, the idler gear 507 is in engagement with gear 506, the latter in turn being engaged with the gear 502A of drive spindle 502. The detailed function of the lever 508 is described in more detail later herein.

EPICYCLIC GEARBOX AND LINEAR DRIVE CONVERTER SECTION 600

As just mentioned, drive spindle 502 passes through the central region of mounting plate 504. Mounting plate 504 effectively defines the boundary between sections 500 and 600 of the gas-liquid mixing assembly.

SUBSTITUTE SHEET (RULE 26) Driven plate 601 is located downstream of mounting plate 504 approximately at the junction of housing portions 114 and 122 of housing section 108 and defines with mounting plate 504 of the gas-liquid mixing assembly a cylindrical space housing the epicyclic gearbox 602. Epicyclic gearbox 602 comprises a set 603 of three planetary gears 603A, 603B and 603C (Figures 22 and 26, of which only gears 603A and 603B are shown in Figure 26). Planetary gears 603A, 603B and 603C are rotatably mounted to respective spigot shafts (not shown) provided on driven plate 601. The previously mentioned terminal gear 502A provided by shaft 502 serves as a sun wheel of the epicyclic gearbox 602.

In the assembled condition of the gas-liquid mixing assembly, main drive gear (ring gear) 604 forming the main drive gear of the gas-liquid atomisation apparatus is press-fitted between driven plate 601 and mounting plate 504, thereby enclosing the space between the two plates to form, as shown in Figures 18 and 20 as well as Figure 26, an outer housing shell forthe epicyclic gearbox 602 within housing portion 114 of housing section 108. Main drive gear 604 is fixed and therefore stationary in operation of the epicyclic gearbox 602. Of course, in the exploded views presented in Figures 11 and 22, main drive gear 604 is shown artificially separated and indeed in a position remote from its position in the assembled apparatus.

The epicyclic gear assembly comprising the planetary gears 603A, 603B and 603C and the main drive gear 604 of epicyclic gearbox 602 is of a type widely available in the marketplace, that employed in the preferred embodiment shown in the accompanying drawings being a Pittman G22A/107:l planetary gearbox available from AMETEK, Inc (after discarding its outer casing).

It will be appreciated that drive from electrical motor 501 is transmitted to epicyclic gearbox 602 by means of engagement between the previously mentioned terminal gear/sun gear 502A of drive spindle 502 with planetary gears 603A, 603B and 603C (planetary gears 603A and 603C are shown in Figure 26 as well as in Figure 22, planetary gear 603B being indicated in Figure 22 only). As main drive gear 604 is fixed so as to be stationary, drive from electrical motor 501 is applied through planetary gears 603A, 603B and 603C to driven plate 601. Driven plate 601 is integral with drive flange 606 (Figure 26)

SUBSTITUTE SHEET (RULE 26) provided at the upstream end of micrometre barrel 608 and integral therewith, drive flange 606 being rotatably mounted within drive shaft main bearing 610. Accordingly, drive applied to driven plate 601 is applied to micrometre barrel 608.

Micrometre barrel 608 is internally threaded over most of its axial length and has micrometre shaft 609 threadedly received therein. Through engagement between the two threads referred to, rotation of micrometre barrel 608 serves to displace micrometre shaft 609 within micrometre barrel 608 linearly along its axis in a direction determined by the direction of rotation of micrometre barrel 608. Between the upstream extremity of micrometre shaft 609 and driven plate 601, a cylindrical upstream clearance pocket 615 is provided to take up axial displacement of the micrometre shaft 609 in an upstream direction (see also the annular downstream clearance pocket 726 provided at the downstream end of micrometre barrel 608, as described hereinafter).

Whilst the stepdown ratio of broadly suitable epicyclic gear boxes for use as epicyclic gearbox 602 may vary, the stepdown ratio in the preferred embodiment shown in the drawings is 100:1. It will be appreciated by those skilled in the art that drive from motor 501 applied through the epicyclic gearbox 602 and drive flange 606 to micrometre barrel 608 is experienced by micrometre shaft 609 as a highly controlled incremental linear displacement on the axis A shown in Figure 26. The function of such displacement will be described hereinafter in connection with section 7 of the apparatus.

Disposed within housing section 108, as shown in Figures 11, 18, 20, 22 and 26, are encoder disc 612 and PCB assembly (controller) 614. Encoder disc 612 is mounted to circumferential sleeve 613 (Figures 11 and 26) disposed about micrometre barrel 608. PCB assembly 614 is mounted to micrometre barrel 608 (Figures 18 and 26), has an embedded microchip and serves as a controller. The encoder disc 612 is a Hall effect trigger provided to enable precision control of rotation of the micrometre barrel 608. To this end, encoder disc 612 registers each complete rotation of micrometre barrel 608, supplying this information to PCB assembly 614 as a series of pulses, one pulse for each complete rotation of micrometre barrel 608. The pulse signals delivered by encoder disc 612 are translated by the controller of PCB assembly 614 into the linear location of the micrometre shaft 609, and thus the size of the gap 725 referred to hereinbelow, and compared to any

SUBSTITUTE SHEET (RULE 26) pre-programmed gap setting of the controller 614. Typically, one micrometre barrel rotation represents a linear displacement of micrometer shaft 609 of 1 micron.

Readings of this information are displayed on a battery-powered Ul display screen 614A (Figures 8 and 9) of the controller 614. Controller 614 controls electrical motor 501 through control of the previously mentioned rotary potentiometer, the potentiometer being actuated in accordance with pre-programming of controller 614 or by manual intervention at the controller, as desired. Such pre-programming may be configured to signal the rotary potentiometer to widen or narrow gap 725 in response to signals directed to the controller 614 from various sensors placed to sense such parameters as temperature and pressure at various points in the atomisation apparatus or the wider system is illustrated schematically in Figure 33.

The micrometre barrel 608 and micrometre shaft 609, as well as components 613 and 612 are made of cast 316L stainless steel CNC machined post-casting.

VENTURI MODULE SECTION (GAS ZONE) 700

General construction and operation

Housed in half-shell 103 of main housing 101 at the downstream end of micrometre shaft 609 and integral therewith is an unthreaded cylindrical body 701 partly of slightly larger cross-section than micrometre shaft 609 (Figures 13 and 26). Cylindrical body 701 is in turn integral with arcuate-faced driven member 702 also housed in half-shell 103 of main housing 101.

In the assembled condition of the apparatus, driven member 702 is received through the upstream end opening of the posterior cylindrical wall section 703 (Figures 23 to 26) of the Venturi module M and is housed wholly therewithin as a discrete component separable from the Venturi module M. A stop or abutment condition with respect to its insertion within the posterior cylindrical wall section 703 is reached when the connection flange 710 described below abuts the upstream end of the posterior cylindrical wall section 703 (Figures 11 and 26) which then encircles driven member 702. When so housed, driven member 702 is sealed by annular seal 704 of the driven member 702, which seal is

SUBSTITUTE SHEET (RULE 26) then disposed between the driven member 702 and the inside surface of posterior cylindrical wall section 703 (Figure 26).

At its downstream end, driven member 702 is formed with a part-spherical surface 705 which in turn forms, when driven member 702 is received as just described, the upstream limit of the gas-receiving chamber 706 (Figures 19, 24 and 25). The concave form of the part-spherical surface 705 assists the handling of pressurized gas within the gas-receiving chamber 706 when the atomization apparatus is in operation.

As best seen in Figures 23, 24 and 25 but also shown in, for example, Figure 11, chamber 706 is formed with four equally spaced integral frame members 707 which together define four windows 708. Each of windows 708 opens radially outwardly from the interior of chamber 706 but is enclosed by an interior wall surface portion 711 (see Figure 26) of halfshell 103. This gives containment integrity to the chamber 706, which constitutes an input region of Venturi module M. The lowermost window 708 is, however, aligned with air feed port 202 of the bayonet assembly 200, as best appreciated from Figure 14, thus providing a gas pathway into chamber 706.

Chamber 706 of the Venturi module M opens at its downstream end to the upstream end of anterior circularly cylindrical section 814/714 of the Venturi module M. The latter component (814/714) is composed of a gas zone portion 714 and a liquid zone portion 814 which together bridge the transition between gas zone 700 and liquid zone 800 (Figures 24 to 26). The (upstream) gas zone portion 714 of the anterior circularly cylindrical section 814/714 is unified with the previously mentioned posterior cylindrical wall section 703, which forms a third principle portion of the Venturi module M. Unification is achieved across the chamber 706 by the previously mentioned frame members 707. The members of the component ensemble 814/714, 703, 707 are integral with one another.

At its upstream end, driven member 702 is provided with the connection flange 710 referred to above. Driven member 702 and Venturi module M are fixed together means of bolts (shown only, but clearly, in the exploded view of Figure 11 but not there designated) passing through connection flange 710 and received in integral bosses 729 of Venturi module M (Figures 10 ,11, 18, 20, 24, 25 and 32C).

SUBSTITUTE SHEET (RULE 26) It will be appreciated that longitudinal displacement of micrometre shaft 609 in an upstream or a downstream direction relative to micrometre barrel 608 directly and correspondingly displaces the overall the Venturi module M. This relative axial displacement determines the size of the gap 725. The latter constructional feature and its operational significance will be explained in detail hereinafter. However, the mechanism of axial displacement of micrometer shaft 609 will first be described.

Accordingly, in terms of downstream axial displacement, displacement of micrometre shaft 609 axially displaces driven member 702, connection flange 710 thereof transferring that displacement to posterior cylindrical wall section 703, which in turn transfers axial displacement to frame members 707 (and the chamber 706, which they define) and anterior circularly cylindrical section 814/714, together with Venturi 715 and gas inlet gallery 722 referred to below. In terms of upstream axial displacement of micrometre shaft 609, it will be appreciated that the bolted connection of flange 710 to posterior cylindrical wall section 703 at bosses 729 ensures that driven member 702 draws the separate Venturi module M (which, as noted above, is an integral ensemble) along with it (see Figures 11 and 26).

Annular downstream clearance pocket 726 provided about cylindrical body 701 receives the downstream extremity of micrometre barrel 608 as cylindrical body 701 is displaced in an upstream direction. In this way, upstream axial displacement of micrometre shaft 609 relative to the downstream end of micrometre barrel 608 is accommodated (see also the cylindrical upstream clearance pocket 615 provided at the upstream end of micrometre barrel 608, as described hereinabove).

Referring in particular to Figure 23, it will be noted that Venturi module M is received for longitudinal displacement, without rotation and without loss of fluid containment, within the internal chamber formed by half-shells 102 and 103 when the latter are unified. The previously mentioned posterior cylindrical wall section 703 (Figures 23 and 26) and the above-mentioned anterior circularly cylindrical section 814/714 are closely housed within the above internal chamber. As so-housed, the cylindrical surfaces of both closely sweep those of the half-shells 102 and 103 during longitudinal displacement of Venturi module M. As shown in Figures 23 and 26, seal 712 together with seal 814A respectively provide a

SUBSTITUTE SHEET (RULE 26) full seal in order to ensure fluid containment. It will be noted that seal 814A is shown on a larger scale in Figures 19 and 21 and also shown in Figures 18 and 20 (the location of seal 712 being indicated in the latter two Figures by its reference numeral but the seal itself not being shown). However, in order to prevent rotation of Venturi module M relative to the shell housing 101, the external face of posterior cylindrical wall section 703 is formed with a set of three diametrically located equally spaced guide bosses 729 (Figures 10, 18, 20, 24, 25 and 32C) which are received in corresponding guide scollops 730 (shown in Figure 10 only) formed in the local interior face of the half-shell 103. The guide bosses 729 and guide scallops 730 serve as a longitudinal displacement guide as the micrometre barrel 608 rotates and drives longitudinal displacement of micrometre shaft 609, whilst restraining rotational displacement. Each of the guide scallops 730 has a sufficient length in the axial direction of the Venturi module M to accommodate the longitudinal travel of the bosses 729 therein.

Figure 29 shows the gap 725 in various conditions of displacement of Venturi module M. Thus, Figure 29A shows the gap 725 at its maximum size is achieved through maximum axial displacement of micrometre barrel 609 in an upstream direction brought about by rotation of micrometre barrel 608 by electrical motor 501 in a first direction. In this displacement condition of Venturi module M, the gap 725 in the preferred embodiment illustrated in the accompanying drawings has a dimension of 2mm (the measurement being taken between the opposed surfaces of larger collar 906 and anterior circularly cylindrical section 814/714). Figure 29B shows a narrower gap 725 achieved, when starting from the condition shown in Figure 29A, by reversing the direction of rotation of electrical motor 501, and thus the direction of rotation of micrometre barrel 608. For most operational purposes, gap 725 will be from 0.1mm 20.6mm in width. In practice, it would be unusual for an operator to wish to close gap 725 completely (ie zero width) although the atomisation apparatus shown in the drawings, with minor re-design, could enable this to be done; this condition of the apparatus (namely with a zero gap 725) is not, however, shown in the accompanying drawings. It will be seen from the three Figures of Figure 29 that changing the width of gap 725 also changes the spacing between gas-contacting frusto-conical surface 801 and surface 908 (both referred to hereinafter) from one another (in other words, the size of gas-liquid receiving and transit passageway (second pre-mixing

SUBSTITUTE SHEET (RULE 26) region) PM2 (which is described later herein). It is this dimension which is operationally important in determining the volume of atomisation liquid supplied to mix with the compressed air supplied to the apparatus. The size of gap 725 is therefore an expression of the size of the passageway PM2; for every micron increase (decrease) in the distance across gap 725 between larger collar 906 and the opposing surface of cylindrical section 814/714, the size of the passageway PM2 increases (decreases) by the same amount although measured as the length of a line drawn across passageway PM2 in Figure 29A parallel to the longitudinal axis of the conduit 721.

Frusto-conical chamber 713 is defined within anterior circularly cylindrical section 814/714 and essentially forms a continuity of the chamber 706 (Figures 19 and 25). As such, a portion of the compressed air supplied to chamber 706 via air feed port 202 of bayonet assembly 200 is forced as a flow of driving gas into frusto-conical chamber 713 and onward to Venturi 715, gas pressure increasing as the flow of gas is funnelled by the conical wall of frusto-conical chamber 713 to converge in the direction of the Venturi 715. Part- spherical surface 705 functions by virtue of its shape as a "lens" directing compressed gas supplied to chamber 706 towards frusto-conical chamber 713 and thence to the Venturi 715.

The frusto-conical chamber 713 terminates at Venturi 715. The ratio between its diameter at its mouth (as measured between the lines 716 and 717 shown in Figure 31) and its diameter at the Venturi 715 (as measured between the lines 718 and 719 shown in Figure 31) is approximately 2.67:1.

The gas-contacting internal face of the frusto-conical chamber 713 has a polished finish produced by chemical electro-polishing techniques which will be familiar to those skilled in the art. Such a polished finish serves the interests of smooth gas transmission to the Venturi 715. The Venturi gas-contacting surfaces are polished, using the same techniques, for the same reason.

It will be seen from Figures 2, 26 and 27 in particular that the gas zone 700 outputs on two separate outputs. One output is of driving gas transmitted directly to the gas outlet subzone (or premixing zone) PM2/905/PM1 of the liquid-gas zone 800 through Venturi 715,

SUBSTITUTE SHEET (RULE 26) as depicted in both Figures. The other output is of non-driving initial mixing gas transmitted via the liquid transit sub-zone 806/807/809 of the liquid zone 800 and then, as a gas-liquid mixture, to the gas outlet sub-zone PM2/905/PM1 in the liquid-gas zone 900. These outputs will both be described in the following paragraphs; further handling of the output gas and, in particular, its admixture with liquid will be described separately hereinafter in the context of liquid zone 800.

As best seen from Figures 31 and 32, Venturi module M is provided proximate to the junction of the chamber 706 with the frusto-conical chamber 713 with an array of gas inlet orifices 720 (Figures 19, 23, 24, 25 and 27) each of which is respective to a gas conduit 721 (Figures 14, 23, 24 and 27), thus forming an inlet gallery 722 (Figure 19, 23 and 25) for the transmission of compressed gas from chamber 706 to the liquid transit sub-zone of liquid zone 800 described hereinafter. Each gas conduit 721 outputs at a respective output orifice 723 (Figure 25), the output orifices 723 as a whole forming an output gallery 724 (Figures 11 and 23 to 25). Each gas conduit 721 is identical to each of the others and their longitudinal axes are parallel to one another.

Gas conduit arrangement

As will be appreciated from the Figures referred to above, each of the conduits 721 (which will be described here for convenience, although each conduit 721 extends from the gas zone 700 to the liquid zone 800) is disposed with its long axis alongside and parallel to that of the next adjacent conduit 721. The conduits 721 are each arranged lengthwise on the surface of a virtual cylinder which is coaxial with the axes of the Venturi 715 and the anterior circularly cylindrical section 814/714, the axes of each adjacent conduit 721 being parallel to those two axes as well as to each other.

Except at the inlet orifices 720, where the conduits 721 originate in the internal conical surface 727 (Figure 31A) of frusto-conical chamber 713, the conduits 721 are, as shown in Figures 31 and 32, obround in diametric cross-section (by term "diametric cross-section" of a conduit is meant a section on a plane which intersects all sides of the conduit and which is intersected orthogonally by the conduit axis). It will be appreciated that where the conduits 721 originate in conical surface 727, the orifices so formed (the gas inlet

SUBSTITUTE SHEET (RULE 26) orifices 720) are indeed obround in configuration but that the opposed parallel sides of the obround are further apart than the separation of the corresponding sides immediately downstream of the orifices 720.

The diametric cross-section in the case of each conduit 721 is identical in size and configuration to the size and configuration of the diametric cross-section of each of the others cut at the same point along the axial length of the conduit 721. Whilst the diametric cross-section of every conduit 721 is identical in configuration at all points, it will be seen from both Figures 31 and 32 that each of the conduits 721 tapers in cross-section in uniform fashion along its entire axial length from a size immediately downstream of the inlet orifice 720 to a smaller size at the outlet orifice 723.

The combination of cross-section configuration and tapering described above is designed to ensure that the aggregate gas output from the gas output orifices 723 is equal to the gas output from the Venturi.

Seen as a cross-sectional configuration, each obround conduit 721, has long sides as shown in Figure 32, which are straight and parallel to one another. Both are tangential to a circle whose centre is on the axis of the Venturi 715. The circle is designated by reference numeral 728 in Figure 32B and Figure 32D (which circle has in each case its centre upon the axis 732 of the Venturi 715, shown contextually in Figures 32A and 32C and also indicated in Figures 32B and 32D) and passes through each orifice (respectively, inlet orifice 720 and outlet orifice 723) at a point centrally along its length.

With respect to the tapering of each of the conduits 721 referred to above:

(i) as shown in Figure 32, the width of the obround of each gas conduit 721 at a point immediately downstream of its inlet orifice 720 (the measurement between the parallel straight sides of the obround taken at the point of cut of section line XXXIIA-XXXIIA shown in Figure 31A) is approximately 1.46recX the same dimension of the gas outlet orifice 723 located downstream at the other end of the same gas conduit 721;

SUBSTITUTE SHEET (RULE 26) (ii) the length of the obround of each inlet orifice 720 (the length of its long axis on a centreline between the half round ends of the obround) is approximately 1.17X the same dimension of the outlet orifice 723.

The ratio between the cross-sectional area of any one gas conduit at each of the two points of measurement mentioned in Paragraphs (i) above (i.e. the ratio orifice 720 : orifice 723) is accordingly 1.73 : 1.00.

The taper profile for any one gas conduit between the two points of measurement mentioned in Paragraphs (i) and (ii) above is linear.

Conduits 721 are formed by spark erosion to provide for smooth transmission of gas along them.

Conduits gas transportation characteristics including CFD studies

The combination of cross-section configuration and tapering described above (combined with the above-mentioned method of forming the conduits 721) has been found to result in a smoothly increasing gas velocity profile along the length of each conduit 721, in particular along the downstream portion equal to the most downstream 25% to 40% of the conduit length. This characteristic is in contrast to the longitudinal gas velocity profile experienced when using a conduit having a circular cross-section. In addition to this feature of the longitudinal velocity profile, the lateral velocity profile is more uniform at most points along the conduit length and, importantly, is highly uniform in the above- mentioned downstream portion representing the final 25% to 40% of the conduit length.

Referring to Figures 35A and 36A, it will be seen that the gas velocity rapidly increases soon after the gas stream enters the inlet orifice of the conduit (namely, inlet orifice 720 in the case of conduits 721) from the plenum space (713 in, for example, Figures 18, 19 and 25), with maximum velocity achieved very quickly but at the expense of producing a very ragged lateral velocity profile. Thereafter, further downstream, before the half-way -point along the conduit, the gas stream proceeds with a continuing uneven lateral velocity profile for the remainder of the conduit length, at the end of which length the gas stream enters first pre-mixing zone PM1 as a somewhat stratified stream via conduit outlet

SUBSTITUTE SHEET (RULE 26) orifices (namely orifices 723 in the case of conduits 721). In contrast, Figures 35B and 36B show a more gradual velocity escalation, leading to a generally uniform lateral velocity profile. The representations in Figures 36A and 36B are repeated in monochrome in Figures 43A and 43B, with an enlargement of a detail of Figure 43B shown in Figure 43C.

In each of Figures 36A, 36B, 40A, 40B and 43C, the square bracketed [numerals] applied to each U-value domain indicate the median value of U taken from the region of the calibration bar having the colour/shade corresponding to that U-value domain; thus, in Figure 36A, for example, the indicator "[95]" appears several times and indicates in each case a U value of 95 m/s, this having been taken from the far right graduation section of the calibration bar which is designated numerically as "90 95 100". These U-value indications are provided to assist an understanding of the foregoing comments as well as for orientation purposes.

In the above connection, due to space limitations, it will be appreciated that in parts of, for example, Figure 36A (and particularly in the case of later monochrome Figures), the space available to depict the smaller of the various U-value domains introduces complexity in terms of designating a particular [U-value number] indicator to the relevant domain; it should be noted that this leads in some cases to positional approximation. To assist clarity in the monochrome contexts of Figures 40A, 40B and 43C, lead lines used to link particular U-value domains with a U-value indicator [number], a contrasting dot has been placed in the domain itself in each case where this appeared to be helpful.

As noted earlier, Figures 43A and 43B are simplified monochrome versions of Figures 40A and 40B, respectively, the former Figures, however, overlaid with depictions of divisions along the length of the represented conduit 721/CC. Figures 43D and 43E are divisional representations separately showing each of the above-mentioned divisions. Figures 43D and 43E accordingly divide the representations shown in Figures 36A and 36B into enlarged component parts enabling an examination the better to understand the conclusions drawn from Figures 36A and 36B. A flow velocity indicator [number] respective to each U-value domain in each such division is represented in the divisional representations shown in Figures 43D and 43E, in some cases by [numeric] indicators in

SUBSTITUTE SHEET (RULE 26) each Figure placed within the particular U-value domain or, in others, by lead lines connecting each respective [numeric] indicator to the domain.

The above-referenced smoothly increasing gas velocity profile along the length of each conduit 721 leads to unimpeded flow of gas along each conduit 721 between input orifices 720 and respective output orifices 723 as compared with conduits having a conventional circular cross-section (one which is constantly circular between inlet and outlet orifices) and a mean cross-sectional flow area of the same magnitude; it is considered that this difference in flow performance may be emphasised where the comparison is made with a conventional conduit of circular cross-section formed by conventional methods such as drilling, but that this factor is a relatively minor one. The improved aerodynamic performance referred to above is accordingly highly significant in its own right. However, as will be described in detail hereinafter, and is in any event inferred from the CFD findings shown in Figures 35B and 36B, it also leads to enhanced interaction between gas and liquid downstream. Specifically, gas supplied by conduits 721 and process liquid supplied by conduits 806 experience improved interaction from the point the gas and liquid streams meet in annular gas + liquid-receiving region (first pre-mixing region) PMl, and are subsequently transmitted with further mixing in the second pre-mixing zone PM2. From a computational fluid dynamics (CFD) standpoint, it is considered that the above- mentioned enhanced interaction between gas supplied by conduits 721 and process liquid infers consequent substantial performance gains in terms of liquid droplet size and size distribution in actual use of the apparatus of the invention in the field.

As noted earlier herein, drive from motor 501 is applied through the epicyclic gearbox 602 and drive flange 606 to micrometre barrel 608 and this is experienced by micrometre shaft 609 as a highly controlled incremental linear displacement on the axis A shown at the righthand side of Figure 26. The same displacement is experienced by the Venturi module M, enabling the latter component of the apparatus to be controllably displaced by small increments relative to more downstream components. These small incremental displacements serve the function of changing the size of the separation gap 725 between the Venturi module M and the upstream terminal of the nozzle 902 (Figure 29. This produces an increase in the width of annular gas-liquid receiving and transit passageway PM2 and an increase in the axial dimension of cylindrical gas-liquid receiving area 905

SUBSTITUTE SHEET (RULE 26) (both of which are referred to hereinafter). Alteration of the quantum of this separation accordingly constitutes a significant modification of the relationship geometry between those members. This changes the flow capacity of the gas-liquid mixing assembly where they meet. This imparts to the gas-liquid atomisation assembly the important ability to cater for different liquid materials, in particular materials of different viscosities. To understand this important feature, it is necessary first to understand the structure of the apparatus in this region and this will be described below in connection with the liquid and liquid-gas zones 800 and 900 of the apparatus.

LIQUID ZONE 800

Liquid receptacle (810)

As will become apparent from the description hereinafter, the nozzle assembly 901 is an important component in the sense that it serves the additional purpose (among others - see below) of contributing to the structural completeness of the liquid zone 800, as well as the fluid divergence processes which take place in the nozzle lumen, leading eventually to plume projection.

Thus, as best seen from Figure 23 as well as in Figures 13, 14 and 26, liquid receptacle 810 is formed in the half-shell 102 of main shell housing 101 and, with the nozzle assembly 901 removed, takes the form of an annular trough. In the assembled apparatus, the nozzle assembly 901 is received through the central region of the annulus of the trough, the larger collar 906 thereof forming by its downstream face 907 (Figures 13, 23, 24 and 28) an upstream liquid barrier of liquid receptacle 810, with the partly bevelled face 918 of nozzle 902 (Figure 28) forming a downstream liquid barrier.

Liquid supply to liquid receptacle 810 is directed from bayonet assembly 200, whose liquid conduit 204 communicates by its liquid feed port 201 and liquid orifice 120 of half-shell 102 of main shell housing 101 with liquid holding area 123 (Figures 15 and, in part, Figure 30) formed in half-shell 102 between liquid orifice 120 and liquid receptacle 810.

SUBSTITUTE SHEET (RULE 26) Liquid Transit & Pre-mix Sub-zone

Outlet of supplied liquid from liquid receptacle 810 takes place along conduits 806 (Figures 21, 23, 26, 28 and 30) whose inlet orifices 809 open into liquid receptacle 810 at liquid inlet gallery 808. The conduits 806 are formed between exterior surfaces of the thinner nozzle wall section 903 of nozzle assembly 901 and the internally-facing surfaces of the nozzle larger collar 906. Liquid inlet gallery 808 is fed with liquid under a pressure equal to that of the gas supplied to chamber 706.

Conduits 806 terminate in outlet orifices 807 provided in an outlet gallery which is indicated in part only in Figure 28 and is designated by reference numeral 805. In use of the atomisation apparatus 1, supplied liquid is output from conduit outlet orifices 807 and enters annular gas + liquid receiving region PMl.

LIQUID-GAS ZONE 900

The liquid-gas zone 900 is made up of nozzle assembly 902 and number of associated fluid pathways. The fluid pathways are in some cases defined by and within the nozzle assembly 902 whilst, in other cases, the nozzle assembly 902 cooperates with, for example, surfaces of the Venturi module M to define a fluid passageway between them as will be described below in detail.

In terms of its make-up, nozzle assembly 902 comprises a nozzle 901 and previously mentioned larger collar 906. The latter collar and smaller collar 920 are integral with the rest of nozzle assembly 902. Nozzle 901 is comprised of a wall 903, 904 which defines a tapering cylindrical nozzle lumen, cylindrical wall section 903 being relatively thin and cylindrical wall section 904 being thicker. As previously mentioned, liquid conduits 806 are formed in nozzle 901 in the region where the thinner nozzle wall section 903 is enclosed by larger collar 906. Smaller collar 920 surrounds the nozzle final expansion zone 916 referred to later. Smaller collar 920 also provides an abutment face 921 (Figures 24 and 28) which interfaces with a radially inwardly extending lip 919 of half-shell 102 for nozzle retention purposes in the assembled apparatus. This is best seen from Figure 23.

SUBSTITUTE SHEET (RULE 26) Cylindrical thicker wall section 904 has a longitudinally extending front lip portion 913 which defines the nozzle outlet 914. Lip portion 913 is received within the annulus of lip 919 of half-shell 102. Immediately upstream of lip portion 913, nozzle 901 is configured with a recessed annular seal 902A (Figures 26 and 28, the latter showing the seal recess only) to accommodate a rubber seal which, as shown in Figure 23, sealingly engages with an interior surface of half-shell 102 when the gas-liquid assembly 100 is housed within shell housing 101.

Larger collar 906 is also formed with an annular recess having an annular rubber seal 906A seated therein (Figures 24 and Figures 26 and 28). This, again, sealingly engages with an interior surface of half-shell 102 when the gas-liquid assembly 100 is housed within shell housing 101 (Figure 23, 24 and 26 to 29).

The nozzle assembly 902 is retained in the assembled gas-liquid mixing assembly within shell housing 101 primarily by engagement between the downstream end of the smaller collar 20 and lip 919 disposed about the nozzle-receiving aperture of the half-shell 102 provided at the extreme downstream end of the shell housing 101. In addition, of course, there is frictional engagement between seals 902A and 906A and the internal surfaces of half-shells 102 with which they are in sealing contact, and there is an overall secure press- fit (interference fit) between the larger collar 906 and half-shell 102 at the circumferential face thereof which engages with the internal face of half-shell 102. In this manner, nozzle assembly 902 is fixed in the atomisation apparatus, and remains stationary throughout its operation. Nozzle assembly 902 is, however, easily released from the body of the atomisation apparatus. Nozzle removal is achieved first by simply retracting bolts 104 (see, for example, Figures 5 and 7) used to secure half shells 102, 103 together. Retraction of bolts 104 enables half-shell 102 to be released from its connection with half-shell 103, with nozzle assembly 902 remaining housed in half-shells 102 (it is retained in position by previously mentioned seals 902A and 906A). Following separation of the two half-shells 102, 103 from one another, the nozzle assembly 902 can then itself be separated manually from half-shell 102 and set to one side for cleaning, more thorough servicing or for storage. A replacement nozzle can then be disposed in the atomiser and may be an identical replacement or else a different nozzle assembly more suited to an upcoming different deployment need.

SUBSTITUTE SHEET (RULE 26) As best seen from Figures 23, 24, 26 and 27, the Venturi 715 opens in general terms to a low pressure divergent sub-zone immediately downstream of its outlet. However, the transition to divergence is somewhat more complex as this divergence is fundamental to the introduction to the system of atomisation liquid, as will be described in detail hereinbelow.

It will be noted that the previously mentioned liquid zone portion 814 of anterior circularly cylindrical section 814/714 of Venturi module M defines the previously mentioned gascontacting frusto-conical surface 801 downstream of, and divergent from, the locus of Venturi 715. With the nozzle assembly 902 (Figures 27 and 28) removed from the gasliquid mixing assembly (as shown in Figure 31A), the frusto-conical surface 801 defines a chamber 731 of corresponding frusto-conical form which is similar in form but of different dimensions to the chamber 713 referred to earlier. However, when the nozzle module 901 is in place as shown, for example, in Figure 26 and Figure 27, the conical surface 908 of the nozzle 902 cooperates with the frusto-conical surface 801 to define a conically annular gas-liquid receiving and transit passageway PM2 between the two conical surfaces (Figures 23 and 27). Whereas, as explained earlier, the geometry of the chamber 713 is designed around the need to funnel driving gas towards the Venturi 715, with the ratio between the chamber mouth cross-sectional area and that of the entrance to the Venturi chosen in that light, the conical divergence of frusto-conical surface 801 in a downstream direction is dictated instead by the need to accommodate the downstream section of the nozzle assembly 901 to form the gas-liquid receiving and transit passageway PIVI2 with desired geometry.

As noted above, and characteristic of Venturis, Venturi 715 opens to a low pressure subzone. This comprises a generally cylindrical gas-liquid receiving area 905 disposed between the Venturi 715 and the upstream end of a short parallel-sided circular cylindrical tube portion 911 which forms the extreme upstream part of the nozzle assembly 902 shown in Figure 28.

Gas-liquid-receiving and transit passageway PM2 is in open communication at one end with the low pressure gas-liquid receiving area 905 mentioned above. Gas-liquid-receiving and transit passageway PM2 is in addition in open communication at its other end with

SUBSTITUTE SHEET (RULE 26) annular gas + liquid-receiving region PM1 (Figures 23, 27 and 29); in short, gas-liquid receiving and transit passageway PM2 connects gas-liquid receiving area 905 with gas + liquid-receiving region PMl.

The gas outlet orifices 723 of gas conduits 721 form a gas outlet gallery 724 (Figures 23 to 25 and Figure 30), as mentioned previously. This provides for the transmission of compressed non-driving gas from chamber 706 to the annular gas + liquid-receiving region PM1. It will be appreciated that the low pressure subsisting in gas-liquid-receiving area 905 (as a result of the gas transmission through Venturi constriction 715) is applied to annular gas + liquid-receiving region PMl via the gas-liquid-receiving and transit passageway PM2. Cooperatively with the elevated pressure of the compressed gas in conduits 721 and the equivalent pressure of the liquid supply to passageways 806 at inlet gallery 808 (as explained hereinafter), this low pressure operates both to:

(i) draw liquid in an upstream direction (looking at the apparatus as a whole) from passageways 806 and through liquid outlet orifices 807 of liquid outlet gallery 805 (Figure 28) into the inner part of annular gas + liquid-receiving region PMl (Figure 27) for initial mixing with gas received from the gallery 724 in which orifices 723 of conduits 721 are comprised, and

(j) withdraw gas-liquid mixture from annular gas + liquid-receiving region PMl into the annular gas-liquid receiving and transit passageway PM2 and thence to gas-liquid- receiving area 905.

As noted earlier, CFD investigation shows that the gas flow in conduits 721 is improved in velocity profile (both in longitudinal and lateral profile) leading up to its introduction into the first pre-mixing zone PMl. Interaction in gas-liquid receiving and transit passageway PM2 is the more significant of the two pre-mixings in the sense that it is this which directly demonstrates performance, that achieved in gas + liquid-receiving region PMl having the importance of being enabling. Figures 37 and 38 report results in support of this, the same results being repeated in monochrome in Figures 41 and 42, in both cases comparing conduit 721 with a conventional conduit designated CC.

SUBSTITUTE SHEET (RULE 26) To assist in understanding the significance of the results shown in Figures 37 and 38, however, reference is first made to Figures 31C and 31D (which, for orientation purposes are best viewed together). Accordingly, Figure 31C shows in diagrammatic form the fluid passageway arrangement wherein the gas conduit 721 (CC) intersects with first pre-mixing zone PM1. Atomisation liquid passes via conduits 806 (not shown in Figure 31C) into first pre-mixing zone PM1 for premixture therein with gas from gas conduits 721 (CC). Leading off from the first pre-mixing zone PMl, the premixture passes into second pre-mixing zone PM2, the latter intersecting low pressure receiving area 905 serving as an atomization zone in which mixed fluid output from the second pre-mixing zone PM2 is exposed to sonic airflow from the Venturi 715, is entrained in the latter and passed into the lumen of the nozzle 902. Referring now to Figure 31D, it will be seen that the atomisation liquid forms a liquid film 816 on a pre-film wall 817 (the lower surface of pre-mixing zone PM2) and is transported by sub-sonic air flow to low pressure receiving area 905. The gas flow stream has a sheer interface with the liquid film as the liquid is relatively viscous, and this is the predominant driving force transporting the liquid film.

The aerodynamic effect of the liquid film on the gas flow upstream of the pre-film region is minimal and thus has no material bearing on the CFD investigation (which was conducted in the absence of liquid, as noted previously) whose results are reported in Figures 37A and 37B.

In low pressure receiving area 905, the leading edge of the liquid film experiences at atomising edge 820 the sonic flow from the Venturi 715. This acts upon the advancing liquid film, breaking up the film into ligaments 818. Ligaments 818 are configurationally unstable and gradually reconfigure, as a result of their liquid surface tension, into spherical droplets 819. These spherical droplets are driven by the sonic air flow from the Venturi 715 along the lumen of the nozzle 902. The atomization process shown thus has a ligament mode and a droplet mode, and may continue in the upstream end of the circular cylindrical tube portion 911 of nozzle 901.

Returning to Figures 37A and 37B, in both cases (ie the second pre-mixing zone PM2 supplied ultimately from either conduits CC or conduits 721), a very thin boundary gas film is shown designated 821. Upon that boundary film (which is differentiated from the rest of the gas flow in terms only of its velocity), gas film 822A (in the case of Figure 37A) or

SUBSTITUTE SHEET (RULE 26) 822B (in the case of Figure 37B) is disposed in transit towards low pressure receiving area 905. Figures 38A and 38B show the boundary regions, respectively designated in Figures 37A and 37B as XXXVIIA and XXXVIIB, on an enlarged scale. It is immediately evident from the above Figures that the velocity of the gas film 822B in Figure 37B is significantly greater than the velocity of the gas film 822A in Figure 37A, that the thicknesses of the gas film 822B in Figure 37B is substantially greater and more uniform than the thicknesses of the gas film 822A in Figure 37A, and that the gas film velocity is more uniform, in the case of the gas film 822B in Figures 37B and 38B, as compared with the gas film 822A in Figures 37A and 38A, across the partial arc of second pre-mixing zone PM2 shown. As shown by comparing Figures 37A and 37 with one another it is clear, without reference to Figure 38, that the gas film 822B is also generally higher velocity; note the generally higher labelled U values noted in Figures 37B and 38B as compared to Figures 37A and 38A (see also Figure 37B2). As noted earlier, Figures 37A, 37B, 38A and 38B have corresponding monochrome equivalents in Figures 41A, 41B, 42A and 42B. In all of the Figures mentioned in this paragraph, depiction of all U values designated for particular velocity domains follows the approach previously exemplified with reference to Figure 36A.

Figure 44 shows the velocity across the gas film for each of conduits 721 and CC compared. The following table summarises the mean, range and standard deviation. The comparison is shown graphically as normalised distributions in Figure 45:

The following headline remarks can be concluded: -

SUBSTITUTE SHEET (RULE 26) 1. Compared to conduits CC, conduits 721 produce a more consistent and high velocity gas film proximate [1] the lower surface of the second pre-mixing zone PM2, upstream of liquid introduction from orifices 807. [1 Technically, the velocity on the wall is zero and the gas film is outside of the wall boundary layer].

2. Mean velocity of gas film in the second pre-mixing zone PM2 was increased by about 27% where conduits 721, as compared with conduits CC, were employed to deliver air to 2 ^nd premixing zone PM2 via first pre-mixing zone PM1.

3. Standard deviation of gas film velocity in the second pre-mixing zone PM2 is reduced by about 42% in the case where conduits 721, as compared with conduits CC, were employed to deliver air to the second pre-mixing zone PM2 via first premixing zone PM1.

4. The improved gas film velocity distribution in second pre-mixing zone PM2 should produce a more coherent and uniformly thick liquid pre-film when using conduits 721 as compared to conduits CC. Liquid film thickness has a significant bearing on the ligament formation (and thus on droplet form and size); accordingly, consistent film thickness and film coherence is a significant objective.

5. Based on predictions from the CFD model, guiding that more uniform liquid prefilm through second pre-mixing zone PM2 to the receiving area 905 should result in less variation in droplet sizes produced during atomisation at the atomisation edge 20 shown in Figure 31C.

Returning to a constructional theme, the annulus of annular gas + liquid-receiving region PM1 is partly defined by the circumference of the thinner nozzle wall section 903 (best seen in Figures 23, 27 and 28) but in the main by the liquid zone portion 814 of anterior circularly cylindrical section_814/714 (at the upstream end of half-shell 102) together with cylindrical nozzle larger collar 906 (Figures 23, 24 and 26 to 28) and by the bevel 910 (Figure 28).

Annular gas + liquid-receiving PM1 accordingly connects the liquid outlet orifice gallery 724 (conduits 721) to the liquid conduits 806 at the outlet orifices 807 of the latter (Figures 28 and 30). Conduits 806 extend back from outlet orifices 807 to the liquid inlet orifices of inlet gallery 808 shown in Figures 21, 23, 24, 26 and 27 and indicated generally in Figure

SUBSTITUTE SHEET (RULE 26) 30. Outlet orifices 807 (Figures 28 and 30) represent the terminal downstream end of the liquid transit sub-zone of liquid zone 800 (seen in terms of the liquid flow direction).

As explained in the earlier description of Section 7 of the atomization apparatus, the Venturi module M experiences the same incremental linear displacement as suffered by micrometre barrel 608 when drive is applied from motor 501. By this means, the separation of Venturi module M from the upstream terminal of nozzle 902 can be altered, with concomitant changes in the width of gap 725. Referring to Figure 29 of the drawings, it will be appreciated that axial movement of the Venturi module M to change the size of the separation gap 725 alters the dimensions of the gas-liquid-receiving and transit passageway PM2, the annular gas + liquid-receiving region PMland the low pressure gasliquid receiving area 905. This increases or decreases the volumetric flow capacity of these voids, respectively, with increased or decreased separation between Venturi module M and the above-mentioned upstream terminal of nozzle 902. These are adjustments which facilitate use of the atomisation apparatus of the invention with different liquid materials of differing viscosities.

The frusto-conical surface 801 and the conical surface 908 of nozzle 902 are both polished by chemical electro-polishing techniques which will be familiar to those skilled in the art. Such a polished finish serves the interests of smooth gas-liquid transmission along the gasliquid-receiving and transit passageway PM2.

Front circularly cylindrical section 814/714 is provided with a seal 814A (Figures 11, 18 to 21 and 23 to 27) by means of which the cylindrical member portion 814 is sealed to the interior surface of half-shell 102.

As described earlier, and as best seen in Figure 27 , the Venturi 715 opens immediately downstream to a low pressure sub-zone comprising a generally cylindrical gas-liquid receiving area 905 serving as an atomization chamber

Gas-liquid mixture-receiving area 905 transitions then into the nozzle assembly 902, in which various zones each characterised by the fluid processes which take place therein can be identified. It will be appreciated that the fluid processes which take place in the nozzle, as well as the locations of each zone, vary with the overall atomisation conditions

SUBSTITUTE SHEET (RULE 26) including the nature of the liquid to be atomised, the fluid pressures and temperatures at which the atomisation apparatus is operated and ambient conditions generally.

As mentioned previously, fluid flow speed is at a maximum, and at the supersonic level, as the gas flow leaves the Venturi 715 and joins with liquid-gas premixture input to the gasliquid mixture receiving area 905 as the premixture is fed thereto via gas-receiving and transit passageway PM2. Supersonic mixing velocity is maintained within the slightly downstream circular cylindrical tube portion 911 of nozzle 901, whereafter the gas-liquid mixture enters a zone in which divergence begins and speed gradually reduces.

Referring to Figures 1 and 28 in particular, the supersonic zone extends slightly beyond cylindrical tube portion 911 but is represented principally by receiving area 905 and tubular portion 911. It is thus of necessity indicated in positionally approximate terms only in Figures 27 and 28 (in part only in the former case) by the reference numeral 912. The supersonic zone 912 is characterised by supersonic collisions between entrained liquid droplets and gas molecules in the entraining gas and between liquid droplets themselves, brought about by high levels of sheer in the liquid-gas stream - all of which it furthers the atomisation process.

As the gas-liquid mixture proceeds along the lumen of the nozzle 901, it enters a driving and expansion zone which is designated in positionally approximate terms in Figures 27 and 28 by reference numeral 915. In driving and expansion zone 915, there is increasing divergence as the cross-section of the nozzle lumen gradually increases. The concomitant expansion of the gas-liquid mixture coupled with continuing supersonic flow gives rise to further mixing of liquid particles and gas as the mixture continues to be driven along the lumen of the nozzle 901.

Driving and expansion zone 915 merges into a final expansion zone towards the end of the nozzle lumen as indicated in Figure 26 by reference numeral 916. In the final expansion zone, atomised particles of atomisation liquid expand to form the precursor of the plume 917 leaving the nozzle exit orifices 914, as shown in Figures 13 and 26.

The components of the nozzle assembly 901 (with the exception of the seals) are all CNC machined parts, with conduits made by spark erosion followed by chemical polishing.

SUBSTITUTE SHEET (RULE 26) D. ATOMIZATION APPARATUS AS PART OF AN INTEGRATED SYSTEM

For operational purposes, the atomisation apparatus described in the foregoing description will form part of an integrated environmental system. The latter includes components for supply of gas and liquid materials together with apparatus components having various control functions, including an overall controller whose programming determines the behaviour of the atomisation apparatus. The atomisation apparatus may be linked through that system to an environment alarm installation which monitors for events, such as a contamination event, in the environment to which event the system is programmed to respond. The integrated system is illustrated in Figure 33 of the drawings.

As shown in Figure 33, a gas supply source 25 is connected to a gas supply line 26 which in turn is connected downstream to gas supply hose 404A. As shown, for example, in Figures 4 to 7, gas supply hose 404A is connected to the gas supply circuit formed internally within the base manifold 406 of the platform and manifold assembly 400 . Without intending to indicate precise positioning, gas supply hose 404A is indicated in Figure 33.

The gas supply source 25 may be a compressor or alternatively may be a pressurised gas container (commonly referred to in the United Kingdom as a “gas bottle"). The context in which the atomisation apparatus is to be used will, of course, determine which one of these alternatives is selected by operators. For example, the finite quantity of gas which can be supplied by one or more pressurised gas containers may make containerised gas suitable for settings where quantities of atomised liquid are predictable (in the sense that gas quantities likely to be required can reliably be estimated). Of course, it is clearly the case that containerised gas is the most practical choice in an emergency situation requiring transportation of equipment to a particular site (as will be illustrated hereinafter). In the case of permanent and semi-permanent installations of the atomisation apparatus, however, a compressor would usually be the most practical choice provided that a source of power is also available to drive the compressor. In this connection, a source of electricity will generally be most convenient but it is entirely practical to drive the compressor by means of a donkey engine. Of course, higher volumes of atomised liquid are anticipated to be necessary in any event.

SUBSTITUTE SHEET (RULE 26) Where entrainment of microorganisms into the air supply is inappropriate, the airstream is filtered to laboratory standards, to avoid contamination, at a point upstream of the base manifold 406.

Gas supply source 25 can be isolated from the bulk of the downstream extent of gas supply line 26 by means of isolating valve 27 which would ordinarily be placed only slightly downstream of gas supply source 25. A flow direction indicator 28A is provided slightly downstream of isolating valve 27, and somewhat further downstream a regulating valve 29 is provided for regulating the gas flow rate in gas supply line 26 and thus the gas pressure in the Venturi module M.

It will be appreciated that fluid flow direction indicators are a practical necessity throughout the system. It will be noted that these are all represented by a solid arrowhead but in the interests of clarity some only of the direction indicators present are designated by means of a reference numeral.

Regulating valve 30 is provided in gas branch supply line 31. Gas branch supply line 31 leads to fluid reservoir 38, which is referred to below in more detail in describing to the liquid materials supply to the apparatus. Similarly, a further gas branch supply line 46 is connected to reservoir 44, which is also referred to below in describing to the possible separate supply to the apparatus of special purpose additive. A regulator valve 33 is provided in line 46 between its connection to liquid reservoir 44 and its connection to gas supply line 26.Turning now to the matter of atomisation liquid supply, the discontinuous liquid phase of the plume of atomised liquid produced by the atomisation apparatus 1 could be any of a very wide variety of different liquid materials. The atomisation liquid will in by far the majority of cases be aqueous and, whilst water itself will be a common atomisation liquid, aqueous solutions and suspensions of various substances will commonly be employed to suit the purpose of a particular treatment (examples of such substances just referred to appear hereinafter) and also take account of the conditions applying to a particular treatment context. However, there are many other examples including normally solid materials which have undergone phase change, by application of heat, to convert them into liquid form.

SUBSTITUTE SHEET (RULE 26) Accordingly, the ultimate liquid source 34 will generally be either (i) a mains supply from the main water grid, the latter being connected directly to liquid supply line 35 or indirectly through a header tank or (ii) in the case of a mobile atomiser unit, a dedicated water bowser. Where the ultimate liquid source 34 is a mains supply from the main water grid, connection indirectly through a header tank will be typical, connection directly to the liquid supply line 35 being limited to contexts where the liquid is water as such, as distinct from an aqueous solution/suspension of a solute/particulate. It will be understood by those skilled in the art that such header tanks are commonly provided in buildings generally and other types of eg public structures such as those which make up underground stations or other installations in an underground train transportation system. Isolating valve 36 isolates the overall integrated system from the ultimate liquid source 34, such isolation being required in most instances by regulation where a water source is the main water grid.

Experience shows that water pressure from a header tank may be inadequate to deliver the required liquid volumes at the required rate. This is less likely to be the case when the ultimate liquid source 34 is the mains water grid. However, in both instances, the available water pressure may need to be supplemented and for this purpose pump 37 is provided in liquid supply line 35.

Liquid supply line 35 feeds into the previously mentioned liquid reservoir 38, via flow direction indicator 28B, in order to provide a standing supply of liquid. Typically, liquid reservoir 38 will have a minimum capacity of 1200 litres when serving 10 atomisers each having a liquid consumption of 1 litre/minute and an operational service period of two hours for the particular treatment in question. Depending on the circumstances of a particular treatment context, a risk buffer may be added to the capacity of liquid reservoir 38 to cater for contingencies and this might be as high as a 100% volume risk buffer when the application is a fire suppression application.

Reservoir 38 is normally sited at an elevated location in order to provide a head pressure to supplement applied gas pressure in providing liquid transfer to the ducting system in the base manifold 406. However, because of limitations in some treatment contexts (essentially a lack of space at the right location, a not uncommon experience in buildings),

SUBSTITUTE SHEET (RULE 26) right-sizing of liquid reservoir 38 is not practical; where this is the case, liquid reservoir 38 will be downsized and a header feed tank (not shown in Figure 33) of appropriate capacity provided intermediate the liquid reservoir 38 and a connection to the main water grid to compensate for volume deficiency in the liquid reservoir 38.

Reservoir 38 is provided with a level sensor 39, typically a ball float valve assembly, which in operation of the system controls water supply to reservoir 38. I

Controller 612 is a programmable electronics module which, as shown in Figure 33, is provided with plural communication lines to various sensor locations within the overall system. Sensors may be used to sense a variety of conditions applying in the treatment context but would primarily be used for sensing ambient temperature, ambient humidity and wind speed and sensing variations in pressure of driving gas supplied to the apparatus 1. Sensor locations will obviously be determined by the conditions for the sensing of which the sensor is provided. When the liquid in the liquid reservoir 38 returns to the required level, sensor or 39 signals controller 612 to close valve 36 and to de-actuate pump 37 until further liquid replenishment to the reservoir 38 is again required.

Expansion tank 41 is provided to manage thermal expansion of liquid in reservoir 38 and to deal with instantaneous surges which may occur when, for example, pump 37 is initially activated, or, if the ultimate liquid source 34 is a high-pressure mains water grid, when isolating valve 36 is toggled back to an open position to reconnect liquid supply line 35 to mains water grid.

The atomisation apparatus 1 of the invention in the preferred embodiment described above a may have a liquid consumption rate as low as 1 litre per minute and typically between 1 and 3 litres per minute when operated at a liquid pressure of 4 bar applied at the liquid receptacle 810 (Figures 23 and 26). Liquid consumption is, of course, a function of both flow rate and droplet size.

In general terms, the low liquid consumption of apparatus 1 is one of its most significant advantages. In this connection, it is self-evident that the greater the amount of atomisation liquid that is used the greater the wetting of surfaces in the treatment environment and also the larger would be the burden operationally in terms of the

SUBSTITUTE SHEET (RULE 26) provision of liquid at the treatment site. However, and importantly, in a fire suppression context the apparatus of the invention is very distinct from customary practice in which large volumes of water are applied to an area of combustion; a typical fire suppression sprinkler system currently available on the UK market consumes water at a rate of 160 - 200 litres per minute. Water mist systems in which water is pressurised by a mechanical pump and ejected as a mist from an outlet are also available; these systems provide a very fine mist of water which evaporates at the fire site whereby air is displaced to starve the fire of oxygen supply with the result that the fire is extinguished. Water mist systems consume approximately 90% less water than conventional sprinkler systems but still suffer from the disadvantage that treatment area surfaces are unnecessarily wetted by the volumes of water used. Atomisation nozzles produce even finer liquid droplets than water mist systems, and are suitable for many fire suppression requirements. However, because their designs do not generally make them capable of adjustments in flow rate and droplet size, they are unsuitable for certain categories of environment where (in the UK, at least) there are regulatory requirements addressing risk of property damage by excess water use. The atomisation apparatus one of the invention enables both liquid flow rate and droplet size to be adjusted, with the result that it can be applied to fire suppression over the spectrum of environment categories (i.e. categories where a low amount of liquid is essential and categories where relatively large amounts of liquid are permitted and generally used, as well as categories in between).

However, although atomisation apparatus 1 of the invention according to the preferred embodiment described above consumes liquid at a modest rate, it may well be deployed for a sufficient length of time that the absolute volume of the liquid consumption is high enough, depending upon the capacity of reservoir 38, for the level sensor 39 to open isolating valve 36 and two actuate pump 37.

Take-out line 42 is shown immersed in liquid reservoir 38 to provide for output of water from the reservoir. As previously mentioned, gas branch supply line 31 branches off from gas supply line 26 and connects to liquid reservoir 38. This connection applies to the tank contents the gas pressure of gas supply line 26, urging liquid in the tank to enter take-out line 42. This liquid then passes via line 43 to liquid supply hose 405A which, as shown, for example, in Figures 4 to 7 is connected to the liquid supply circuit formed internally within

SUBSTITUTE SHEET (RULE 26) the base manifold 406 of the platform and manifold assembly 400 . Without intending to infer precise positioning, liquid supply hose 405A is indicated in Figure 33. As liquids are incompressible, the gas pressure applied to the liquid in tank 38 is experienced in liquid supply hose 405A and elsewhere in the base manifold 406 of the platform and manifold assembly 400 . Indeed, the arrangements described above for the supply of liquid and gas to base manifold 406 ensure that the pressure of liquid in liquid holding area 123 (Figures 14 and 15 and, in part, Figure 30) of the atomiser and in liquid receptacle 810 (Figures 14, 23 and 26) thereof are equal to the pressure experienced in chamber 706 of the Venturi module M.

Secondary liquid reservoir 44 is provided for containing a supply of special purpose additive, typically a special purpose additive for neutralising particular toxic substances which might be released into an environment. As will be seen in Figure 33, secondary liquid reservoir 44 is connected via isolating valve 45 to liquid supply line 43. It will be recognised that a special purpose additive can be delivered from liquid reservoir 44 to the liquid stream in liquid supply line 43 by applying gas pressure through gas branch supply line 46 and regulator valve 33, so causing special purpose additive to pass from liquid reservoir 44 via line 47 to liquid supply line 43 and from there into liquid supply hose 405A. Controller 612 provides quantitative control on the amount of special purpose additive introduced into liquid supply line 43 through its control of regulator valve 33 and isolating valve 45. A special purpose additive for the purposes of secondary liquid reservoir 44 will usually be an agent to be used in an emergency to deal with a threat in the form of a hazardous materials release where the identity or probable identity of the hazardous material is known and where consequently so is the agent needed to neutralise it. The close proximity of the secondary liquid reservoir 44 to atomisation apparatus 1 enables rapid deployment of the selected special purposes additive. This rapid deployment can be made even more rapid by disposing the secondary liquid reservoir 44 adjacent the nozzle outlet 914 of atomisation apparatus 1. The atomisation apparatus 1 of the invention in the preferred embodiment described above is deployable in many different settings for many different purposes. Examples are as follows: -

1. Disinfection (e.g. disinfection of surfaces of the kind coming into frequent human contact; disinfection of surfaces in healthcare environments, in particular

SUBSTITUTE SHEET (RULE 26) operating theatres in hospitals; disinfection of spaces, such as the internal ducting, of air-conditioning systems, especially those in public buildings such as hotels and those in workplaces such as offices);

2. Decontamination of environments (e.g. to neutralise harmful substances by means of neutralising chemicals);

3. Particle encapsulation (e.g. encapsulation, and thus immobilisation, of asbestos particles in legacy constructions using asbestos as a sheet material or insulation; encapsulation of dust produced in industrial processes such as timber working; encapsulation of microorganisms, for example in exhaled droplets);

4. Humidification of environments to provide optimum levels of moisture;

5. Fire and smoke suppression;

6. Crowd management (achieved through fog generation).

In some cases, for example in a setting where atomised liquid is to be applied to immobilise airborne particles produced in an explosion, there may be no viable electricity supply which can be used to drive electric motor 501 with the result that powered operation of the linear drive module 500, 600 (Figure 2) is disabled. This could preclude the adjustment of the separation gap 725 to facilitate the use of the atomisation apparatus with the optimum liquid for the context and in so doing undermine the objectives of deploying the atomisation apparatus (whilst, of course, the apparatus remains otherwise functional as transmission of drive gas and atomisation liquid through the apparatus can still be effected without electrical power). As shown in various of the Figures, including in particular Figures 3 to 7, 11, 13, 22 and 26, this problem is circumvented by the provision of the previously mentioned manual drive gear assembly 510 (Figure 18) and cranked lever 508 to enable manual intervention when no viable electricity supply is available. Actual use of this facility of the apparatus of the invention is described below in describing operation of apparatus 1 in general.

E. OPERATION OF THE APPARATUS OF THE INVENTION

GENERAL OPERATIONAL DESCRIPTION

SUBSTITUTE SHEET (RULE 26) In terms of operation, it should first be noted that the atomisation apparatus 1 is modular in the sense that the atomiser housing assembly 100 and bayonet assembly 200 together form a single unit which is separable from the balance of the apparatus 1 by means of a simple rotational action applied manually to the unit 100, 200, whereby the bayonet assembly 200 is released from its fixed position within socket assembly 300 (Figure 12) and can be withdrawn manually in an axial direction of the bayonet assembly 200 from within socket assembly 300. This modularity assists portability of the apparatus 1, which may more easily be conveyed to a place of installation (in the case that apparatus 1 is to be mounted to a substrate in a building structure) and more easily and safely transported to a place where the apparatus is to be operated.

In either case, the atomiser housing assembly 100, if it is separate, is mounted by means of bayonet assembly 200 within the socket assembly 300 by an entirely manual mounting. This comprises first manually offering up the bayonet assembly 200 to the socket of the socket assembly 300 so that the spigots 211 (Figures 17a, 17B and 17C) of the bayonet assembly 200 are aligned with the arcuate pathway 316 (Figure 12) of the socket assembly 300. The operator then manually applies a rotational action to the unit 100, 200 in the direction counter to that mentioned above whereby the spigots 211 become seated on the bottom of the arcuate pathway 316 and the spring loading mechanism 214 (not shown as such but merely by its location in Figures 13 and 15) is placed in detention. Despite the ease with which mounting and de-mounting process can be effected, the bayonet assembly 200 is, by the above noted operation, securely received within the socket assembly 300 and ready for operation once services have been connected to the apparatus 1.

With the apparatus 1 mounted, liquid and gas hoses 404A 404B then respectively connected to liquid and gas sources, in the case of a fixed apparatus 1 mounted to the substrate of a building structure, the liquid source will most commonly be a water source forming part of the building infrastructure and, depending on circumstances such as scale, the gas source may be a compressor in the case of a mobile apparatus 1 mounted to a trolley or other kind of vehicle, the liquid source will most commonly be part of the local infrastructure or all may be provided by a bowser co-transported with the apparatus 1 and

SUBSTITUTE SHEET (RULE 26) the gas source will commonly be containerised pressurised air or could be supplied by an on-site compressor or a compressor co-transported to site with the apparatus 1.

If, for any reason, the nozzle assembly 902 is to be replaced, the shell housing 101 can be separated into half-shells 102 and 103 by releasing bolts 104 whereby the nozzle assembly 902 (Figure 28) can be accessed, removed and the replacement nozzle assembly 902 inserted. Such replacement nozzle assembly is will, of course, be a nozzle assembly having the same external configuration as the nozzle configuration which has been removed; however, the internal configuration may be different if it is judged that a nozzle having such different characteristics is required for the operation in question. A nozzle might need permanent replacement by a new nozzle due to damage or wear but removal for cleaning/servicing or replacement for the purposes of the field requirements of a particular application context are more likely reasons.

As previously noted, apparatus 1 is equipped with a linear drive module 500, 600 (Figures 11 and 18 to 22 in the gas-liquid mixing assembly 500 - 900 which serves to vary the size of gap 725. This is driven by electric motor 501 (Figure 22). Power will be supplied by the operator connecting supply lead 124 of the apparatus 1 either to a local supplier forming part of the infrastructure of the treatment site or, in the case of a mobile apparatus 1, supplied either by a mobile generator or battery source co-transported to the treatment site with apparatus 1.

Having set up the apparatus physically in the above manner, and also positioned the assembly, in the case of a mobile apparatus 1, in the correct position within the treatment site, the operator will next set operation parameters at the user interface of controller 614. Parameters include the size of gap 725 (Figure 29A), a parameter varied to suit different liquid materials the duration of the treatment and whether a special purpose additive is to be introduced from secondary liquid reservoir for into the liquid stream supplied via hose 404A to the platform and manifold base 400. Of course, whereas portable versions of apparatus 1 experience a variety of different requirements by their very nature, there is likely to be less requirement for different settings in the case of a fixed apparatus 1, although nevertheless such a fixed apparatus 1, controller 614 will normally be equipped to provide such options.

SUBSTITUTE SHEET (RULE 26) Referring to the previously mentioned cranked lever 508, this component is provided to deal with the contingency of an electrical power failure at a treatment site where the apparatus 1 has been placed for operation. In the case of a mobile apparatus 1, it would normally be best practice for a reserve means of power supply (e.g. a battery or a generator) to be co-transported to the treatment site with apparatus 1. Where this is not the case, and in cases where apparatus 1 is fixed to a substrate forming part of the treatment site, cranked lever 508 provides a means of adjusting gap 725 even when there is no electrical power. Cranked lever 508 is provided with a mechanical hex key at the end of its shorter crank arm which, in the apparatus condition shown in Figure 22, has been inserted into the hexagonal recess at the upstream axial end of shaft 509. Idler gear 507 mounted to shaft 509 can accordingly be rotated by manual turning of lever 508 in order to apply manual drive rotation to gear 506. Gear 506 is itself engaged with terminal gear 502A of drive spindle 502. Manual drive rotation is therefore applied through the gearbox 602 to micrometre barrel 608, this rotational movement ultimately being converted to linear displacement of Venturi module M. Cranked lever 508 is accordingly an ancillary tool enabling manual adjustment of gap 725 for adaptation of the atomisation apparatus to suit different liquid materials. The mechanical hex key of cranked lever 508 is disengaged from the hexagonal recess at the upstream axial end of shaft 509 once the required manual adjustment of gap 725 has taken place. It will be appreciated that when the motor 501 is powered, the gears of manual drive gear assembly 510 are rotated but apply no significant load to the electrical motor 501.

The atomisation apparatus 1 of the invention in the preferred embodiment described with reference to the accompanying drawings has the capacity to deliver a substantial plume from the nozzle outlet 914 at the front of the downstream section of the apparatus (shown as 700, 800, 900 in Figure 33). The plume will be conical in form (divergent from the nozzle outlet) and, on the basis of operation at the levels of the design performance set out in Section A hereinbefore, will normally measure 4 metres in diameter at the cone base and 5 meters in overall length (measurements +/- 0.5 M). Accordingly, the apparatus has the capacity to apply atomised liquid droplets over a large area.

LIQUID MATERIALS

SUBSTITUTE SHEET (RULE 26) As mentioned previously, any one of a very wide variety of different liquid materials may be atomised using the atomiser of the invention; examples of materials used in solution or suspension form include those listed below (the parenthetical percentage figures refer to the concentration of the agent concerned in aqueous solution):-

• Peracetic acid ( 0.1-5%)

• Peroxygen compounds, such as the peroxy acid ester (1-5%)

• Hydrogen peroxide ( 0.1-30%)

• Hypochlorous acid ( 0.1-1%)

• Sodium hypochlorite (0.1-20%)

• Potassium peroxymonosulphate (marketed under the trade mark "Oxone") ( 0.1- 1%)

• Chlorine dioxide ( 0.1 - 1% ppm)

• Quaternary ammonium compound (1- 5%)

• An adhesive such as a polyvinyl acrylate adhesive

• Radiological decontaminants such as RDS-2000, a two-part formulation designed for the removal of radioactive contamination of surfaces

As will be well known to those skilled in the art, certain materials may need in practice to be pre-mixed e.g. with a liquid medium prior to incorporation into the liquid supply.

In cases where the liquid material is not water (for example, if it is an aqueous solution of a sanitisation agent such as sodium hypochlorite), it is to be noted that the liquid source should not be connected to a main water grid (even if isolated by and isolating valve) but should be connected via an intermediate header tank.

In order to provide for provision of different liquids to the base manifold 406, the overall integrated system is provided with isolating valves 48, 49 which are respectively connected to alternative liquid sources which are not shown in Figure 33 but which will in practice supply those alternative liquid materials in the same manner as described above for the provision of liquid taken out of primary reservoir 38 via take-outline 42. As an alternative, the necessary agent (for example, one of the agents exemplified above) could be introduced secondary liquid reservoir 44).

SUBSTITUTE SHEET (RULE 26) ILLUSTRATIONS OF PARTICULAR APPLICATIONS

The following Illustrations are intended to illustrate practical situations in deploying the apparatus of the invention at an application site and are provided by way of example only and without limitation:

Illustration 1 - Portable and fixed Systems Compared

Portable atomisation apparatus according to the invention range from single atomisation apparatus, trolley-mounted together with a pressurised gas cylinder (suitable for environments where access is restricted, examples of such application sites being hospital departments, veterinary practices and dental surgeries) to truck- or trailer-mounted whispered units (“whispered" is a term used in the field to refer to suppression of sound produced from such machinery as electricity generators and air compressors) which can be deployed at application sites with ready vehicular access, in particular application sites accommodating live indoor or outdoor events, such as sports events, where disinfection and/or humidification treatment is to be provided. Of course, application sites with restricted access tend to be modestly-sized application sites where it can be expected that, for example, a decontamination implementation can be achieved relatively quickly, often in less than an hour, with required levels of containerised gas being entirely manageable.

Illustration 2 - Portable Systems used for Site Decontamination

Portable systems in which an atomisation apparatus according to the invention is combined with a containerised supply of pressurised gas can be constructed as extremely light-weight and very manoeuvrable equipment which is completely self-contained and which can be programmed manually and operated without connection to any in-house service at the application site. This avoids the need for trailing hoses and power connection which are hazardous, difficult to clean and have a tendency to risk damage to property when connections are required through building apertures such as doors and windows.

In practice, an operator will load a vehicle with a number of gas cylinders together with a number of spare pre-filled cartridges each containing an agent to be dissolved or dispersed

SUBSTITUTE SHEET (RULE 26) in water (or other solvent or dispersion medium) sufficient to carry out treatment operations likely to amount to one full day of work and involving, probably, as many as 20 application sites. It should be noted that such pre-filled cartridges as mentioned above would ordinarily be bar-coded, the coding being read by the system as programmed for the particular treatment application in question and rejected by the system if not the correct code for the programmed treatment. The vehicle would also carry an on-board compressor in order to refill gas cylinders. Spare nozzles can, in view of their modest size be carried by the vehicle in order to deal with the contingency of damage being incurred during transit and also to accommodate changes in workplan.

Once the application site is secured and ready for use (this would involve a series of standard checks for health and safety and, commonly, a number of other formal matters arising from local regulatory and context circumstances), the operator would enter the treatment zone via an air-lock access void in order to check and set the atomisation apparatus for the correct operation. The operator would then exit the treatment zone, always locking the access to prevent intrusion, and actuate the atomiser through a remote control module.

The overall treatment program might typically have a duration of approximately one hour in order to complete, for example, decontamination of a contaminated application site. The treatment leaves very little, if any, residue to be cleared up. However, the operator would enter the treatment zone, remove the system, wipe down hard surfaces and then leave the treatment zone after conducting a standard set of site departure procedures constructed according to protocols well-known to those skilled in the art and familiar with applicable local regulatory requirements.

Illustration 3 - Portable Systems used for Spectator well-being and audience Management

The large audiences commonly found at events such as sport events give rise to substantial audience management responsibilities to event organisers. First, particularly in the case of outdoor events during hot weather, individuals within audiences can suffer from heat and this may range from minor discomfort to trauma where spectators have been

SUBSTITUTE SHEET (RULE 26) overcome by heat exposure. Secondly, audience inflows, respectively, just prior to the start of an event and just after the event has terminated are very intense and imperatively must follow defined a route within e.g. a stadium both in the interests of movement efficiency and safety; in addition, individual audience elements can catalyse behaviours ranging from the undesirable to the unsafe in significantly large segments of a large audience. As will be described below, an atomised plume of water droplets can be used to assist audience management in both these contexts.

An atomised plume of water droplets can be used for the purposes of humidification and concomitant cooling in order to alleviate heat-mediated discomfort experienced by persons in an audience during hot weather, exacerbated by the relatively high density of individuals in any audience. Such a plume is harmless to persons. However, whilst being harmless, the plume can be used to deter audience movement in an undesired direction. This can be achieved without actually directing the plume to the persons concerned. Nevertheless, by directing a plume towards misbehaving elements in an audience, specific discomfort can be used in relatively extreme circumstances without causing harm to persons. It will be appreciated that so-called “water cannons" have commonly been used in crowd control. Use of a plume of water droplets can be used to similar effect but, as a relatively passive approach to audience management, constitutes a considerably less provocative measure as compared to “water cannons".

Relatively large portable atomisation apparatus units according to the invention will be required in the above applications which would be specially designed for purpose and transported by a heavy goods vehicle equipped with a crane enabling units to be unloaded to suitable positions for commissioning and subsequent use. In order to provide for sustained use over significant periods, a diesel-powered source of compressed air is required. Ancillary equipment such as barriers and personal protection equipment would, of course, normally be provided.

SUBSTITUTE SHEET (RULE 26) F. REFERENCE NUMERALS LIST

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