Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
ATOMISER NOZZLE
Document Type and Number:
WIPO Patent Application WO/2016/156883
Kind Code:
A1
Abstract:
An atomiser nozzle (10) for restricting and atomising a flow of water from a tap, the atomiser nozzle (10) comprising a housing (12) having an inlet (14), an outlet (16), and an internal chamber (18) in communication with the inlet (14) at one end and the outlet (16) at its other end, wherein the outlet (16) is provided by an aperture through the outlet end of the internal chamber (18); a deflector (22) is disposed within the internal chamber (18) and spaced from the outlet (16) to form a sub-chamber (38) between the deflector (22) and outlet (16), the sub-chamber (38) progressively narrowing from the deflector (22) to the outlet (16); the deflector (22) includes a channel (34) disposed along its length and at least one lateral aperture (35), the channel (34) extending partway through the deflector (22) and intersecting the at least one lateral aperture (35); and an annular space (24) is disposed between the exterior of the deflector (22) and interior wall (18a) of the internal chamber (18), the annular space (24) communicating with the outlet (16); in use, the flow of water swirling through the annular space (24) and towards the outlet (16) as it passes through the sub-chamber (38).

Inventors:
SUGDEN-BROOK WESLEY (GB)
Application Number:
PCT/GB2016/050954
Publication Date:
October 06, 2016
Filing Date:
April 04, 2016
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
DRENCHED LTD (GB)
International Classes:
E03C1/02; B05B1/34; E03C1/08
Domestic Patent References:
WO2012090118A12012-07-05
WO2012094786A12012-07-19
Foreign References:
US20110284661A12011-11-24
US20120261489A12012-10-18
Attorney, Agent or Firm:
GAMES, Robert et al. (County House Bayshill Road,Cheltenham, Gloucestershire GL50 3BA, GB)
Download PDF:
Claims:
CLAIMS

1. An atomiser nozzle for restricting and atomising a flow of water from a tap, the atomiser nozzle comprising a housing having an inlet, an outlet, and an internal chamber in communication with the inlet at one end and the outlet at its other end, wherein

the outlet is provided by an aperture through the outlet end of the internal chamber;

a deflector is disposed within the internal chamber and spaced from the outlet to form a sub-chamber between the deflector and the outlet, the sub- chamber progressively narrowing from the deflector to the outlet;

the deflector includes a channel disposed along its length and at least one lateral aperture, the channel extending partway through the deflector and intersecting the at least one lateral aperture; and

an annular space is disposed between the exterior of the deflector and interior wall of the internal chamber, the annular space communicating with the outlet;

in use, the flow of water swirling through the annular space and towards the outlet as it passes through the sub-chamber.

2. An atomiser nozzle as claimed in claim 1, in which the aperture is through the centre of the outlet end of the internal chamber.

3. An atomiser nozzle as claimed in claim 1 or 2, in which the aperture has a diameter in the range of 0.1 mm to 3 mm.

4. An atomiser nozzle as claimed in any of claims 1 to 3, in which the annular space spans 1 mm or less.

5. An atomiser nozzle as claimed in any of claims 1 to 4, in which the deflector includes a circumferential lip, and the internal chamber includes a circumferential ridge, the lip engaging the ridge when the deflector is disposed within the internal chamber.

6. An atomiser nozzle as claimed in any preceding claim, in which the channel and at least one lateral hole intersect at a substantially perpendicular angle.

7. An atomiser nozzle as claimed in any preceding claim, in which the internal chamber is domed at the outlet end.

8. An atomiser nozzle as claimed in any preceding claim, in which the deflector includes at least one notch, in use the at least one notch inducing swirl in the flow of water within the sub-chamber.

9. An atomiser nozzle as claimed in claim 8, in which the at least one notch is straight or curved.

10. An atomiser nozzle as claimed in claim 8 or 9, in which the at least one notch is disposed at an oblique angle.

11. An atomiser nozzle as claimed in any preceding claim, in which a pair of opposing lateral apertures are provided.

12. An atomiser nozzle as claimed in claim 11, in which a pair of opposing notches are provided.

13. An atomiser nozzle as claimed in claim 12, in which the lateral apertures and the notches are rotationally offset from one another on the deflector about its longitudinal axis.

14. An atomiser nozzle as claimed in any preceding claim, in which the deflector has multi-fold rotational symmetry about its longitudinal axis.

15. An atomiser nozzle as claimed in any preceding claim, in which the housing includes an external male threaded portion to screw into a corresponding threaded portion of the tap.

16. An atomiser nozzle as claimed in any preceding claim, in which the inlet includes a filter having a plurality of apertures provided therethrough.

17. An atomiser nozzle as claimed in claim 16, in which each aperture is 2 mm in diameter or less.

18. An atomiser nozzle as claimed in any preceding claim, in which the sub- chamber includes at least one groove for directing the flow of water to the outlet.

19. An atomiser nozzle as claimed in claim 18, in which the at least one groove spirals towards the outlet.

20. An atomiser nozzle as claimed in any preceding claim, in which the deflector has one or more chamfered edges.

21. An atomiser nozzle as claimed in any preceding claim, in which one or more of the following have hydrophobic properties: the deflector, the internal chamber, the sub-chamber, the outlet.

22. An atomiser nozzle as claimed in any preceding claim, when attached to a tap for providing an atomised flow of water.

23. An atomiser nozzle for restricting and atomising a flow of water from a tap, the atomiser nozzle comprising a housing having an inlet, an outlet, and an internal chamber in communication with the inlet at one end and the outlet at its other end, wherein

the internal chamber is substantially cylindrical and domed at the outlet end, the outlet being provided by an aperture through the dome;

a deflector is disposed within the internal chamber, the deflector being substantially cylindrical and including a channel disposed along its length and at least one lateral aperture, the channel extending partway through the deflector and intersecting the at least one lateral aperture; and an annular space is disposed between the exterior of the deflector and interior wall of the internal chamber, which communicates with the dome; in use, the flow of water swirling through the annular space and accelerating towards the outlet as it passes through the dome.

24. An atomiser nozzle substantially as described herein, with reference to and as illustrated in Figures 1 to 4, Figures 5 to 8, Figure 9, and Figure 10 of the drawings.

Description:
ATOMISER NOZZLE

The present invention relates to an atomiser nozzle, and more particularly to an atomiser nozzle for a tap which can generate an atomised flow of water.

BACKGROUND TO THE INVENTION

In developed countries, kitchens, bathrooms and washrooms typically include one or more taps to dispense water. These are typically activated by manual translation or rotation of a handle, controlling the flow rate of water by opening a valve. The water is typically dispensed as a smooth stream (i.e. having laminar flow), with the stream breaking up with increasing distance from the tap. Hands may be washed or food may be rinsed, for example, using water from the tap. Modern public toilets and washrooms may also have arrays of taps to cope with higher throughput of people. These taps may have mechanisms for dispensing water in limited bursts to avoid wastage, as running taps left unattended may not be noticed quickly, i.e. before large amounts of water have been dispensed and wasted. These taps also tend to dispense water in a laminar flow, and use an aerator to minimise waste, although a single aperture nozzle may be utilised.

In both cases, taps in the home and taps in public washrooms dispense large volumes of water per second. In global terms, water shortage (and the energy consumed in its usage) is a growing problem for a variety of reasons. It is therefore imperative to reduce wastage of water and use only that which is necessary. When washing hands, for example, the volume of water required to wet the surface of each hand is minimal when compared with the disproportionately large volume of water typically dispensed from a tap in such an operation. The same is true of rinsing hands of soap once lathered. The only way to minimise water usage through a standard non-specialised tap is to purposefully run the tap slowly, i.e. only turn the handle slightly, releasing the valve to a minimal extent and issuing a slow stream of water. However, the stream is still laminar and still contains excess water for the intended purpose. Furthermore, the majority of people will not do this, or remember to do this, each time they use a tap. Equally, the taps provided in public washrooms may not even provide a way to vary the flow rate of water dispensed, if they do not have a handle that directly controls opening of the valve within the tap. It is an object of the present atomiser nozzle for a tap to substantially reduce or obviate the aforementioned problems.

STATEMENT OF INVENTION According to the present invention, there is provided an atomiser nozzle for restricting and atomising a flow of water from a tap, the atomiser nozzle comprising a housing having an inlet, an outlet, and an internal chamber in communication with the inlet at one end and the outlet at its other end, wherein

the outlet is provided by an aperture through the outlet end of the internal chamber; a deflector is disposed within the internal chamber and spaced from the outlet to form a sub-chamber between the deflector and the outlet, the sub-chamber progressively narrowing from the deflector to the outlet;

the deflector includes a channel disposed along its length and at least one lateral aperture, the channel extending partway through the deflector and intersecting the at least one lateral aperture; and

an annular space is disposed between the exterior of the deflector and interior wall of the internal chamber, the annular space communicating with the outlet;

in use, the flow of water swirling through the annular space and towards the outlet as it passes through the sub-chamber.

This substantially limits the rate at which water is dispensed from a tap in use, minimising the degree to which water is wasted. Water is atomised by the nozzle so that the flow of water emerges as micron-sized droplets rather than a coherent stream, creating a mist or spray with a very high surface area to volume ratio. This allows a user to wet the surface of their hands using just a thin film of water, consuming far less water than a conventional tap without an atomiser nozzle according to the invention. Advantageously, the overall water savings by using the atomiser nozzle on a tap are around 98% by volume, comparing hand washing routines of fixed length with and without use of the nozzle. Secondly, the spray pattern can be carefully controlled at a wide range of water pressures. Traditional atomiser nozzles require high water pressure to create an atomised spray and do not operate effectively under 1.5 bar, and particularly not under 1 bar, but the present atomiser nozzle can operate between from 0.8 bar to 8 bar. This also allows use with both domestic and commercial water supplies around the world. Furthermore, the nozzle spray angle remains relatively constant across the pressure range, which prevents pressure fluctuations causing splashing in use. This in turn minimises the transfer of bacteria via splashes of water from hands to clothing whilst washing hands, for example.

The deflector is spaced from the outlet to provide the sub-chamber within the internal chamber. The sub-chamber may be substantially conical or substantially hemispherical, for example, allowing the sub-chamber to taper towards the outlet. The sub-chamber directs and accelerates the swirl of water into the outlet. It also acts as a reservoir into which water can accumulate and swirl around prior to entering the outlet.

A further benefit is to hygiene, as conventional systems require a mixer valve to reduce the temperature of hot water prior to being dispensed, which can support the growth of micro-organisms such as Pseudomonas and Legionella. By atomising water at its outlet, the atomiser nozzle does not require a mixer valve, reducing the cost of installation. When using hot water, the droplets formed by the nozzle will cool much more quickly in air compared to a coherent stream of hot water (due to their large surface area and low mass), reducing the temperature sufficiently that a user does not scald themselves. Furthermore, using cold water, the minimal volume of water wetting a user's hands will have a much smaller cooling effect compared to a coherent stream of cold water (again due to their large surface area and low mass). Hence, a user will not numb their hands when using cold water, in winter for example. As users become accustomed to 'cold' water being sufficiently warm for hand washing, less heated water will be used, saving energy and reducing resultant C0 2 emissions.

Additional benefits arise for aircraft and ships, for example, which carry or produce fresh water for hand washing, for example. If over 90% less water is used per hand washing operation, less water will need to be carried by an aeroplane, for example, and so less fuel will be expended carrying water unnecessarily. Similar benefits will be derived for processing sea water into fresh water on board a ship, for example.

The aperture may be provided through the centre of the outlet end of the internal chamber. The aperture may have a diameter in the range of 0.1 mm to 3 mm (inclusive) to achieve a wide conical dispersal of water droplets from the swirl of water entering the outlet, covering a large area of a sink. This optimises the range of droplet sizes dispersed from the outlet, with smaller droplet sizes being produced by smaller apertures. The droplets generated by the aperture are small (up to 500 microns in diameter) and thus have low masses, ensuring that (on contacting a sink) there is relatively minimal splashing compared to a tap without the nozzle.

The selected range is advantageous because an aperture of less than 0.1 mm generates too fine a spray or mist, which tends not to wet hands in a way that permits effective hand washing, for example. Equally, an aperture of greater than 3 mm generates too many excessively large droplets, i.e. minimal atomisation, wasting water. In other words, the narrow diameter of the outlet reduces the rate at which water can be dispensed, minimising waste. The annular space may span 1 mm or less. Preferably, the annular space spans substantially 0.2 mm or less.

The flow of water increases in velocity as it transitions out of the deflector into the narrow annular space (or annular gap), accelerating as it swirls spirally around the interior wall of the internal chamber. The increased flow velocity is accompanied by a drop in fluid pressure, which increases the propensity for water to form a fine (i.e. atomised) spray of micron-sized droplets when exiting through the aperture.

The deflector may include a circumferential lip, and the internal chamber may include a circumferential ridge. The lip may engage the ridge when the deflector is disposed within the internal chamber. The lip is wider than the ridge. This allows the deflector to be seated within the internal chamber such that its lower portion is surrounded by the annular space, which supports atomisation of the flow of water in use. The deflector includes a channel disposed along its length, and at least one lateral hole. The channel extends partway through the deflector and intersects the at least one lateral hole. In other words, the channel has an open end and a closed end, and intersects the at least one lateral hole at its closed end. Preferably, the channel and at least one lateral hole intersect at a substantially perpendicular angle. More preferably, the at least one lateral hole intersects the channel at a distance inset from the closed end.

The channel and lateral hole(s) permit the passage of water from the inlet to the outlet indirectly, changing the flow path of the water (i.e. deflecting it) by having the channel closed at one end. By having at least one lateral hole intersect the channel at a perpendicular angle, the flow of water is directed onto the interior wall of the internal chamber to form a swirl of water.

The channel may have a cross-sectional area less than the sum of the cross-sectional areas of the or each lateral hole. The at least one lateral hole may taper outwardly. In other words, the at least one lateral hole may have a smaller diameter at the exterior of the deflector than at the point of intersection with the channel. Tapering the or each hole focusses the flow of water released into the annular space, establishing a coherent swirl of water more readily. The internal chamber may be domed at the outlet end.

The deflector may include at least one notch. In use, the at least one notch may induce swirl to the flow of water within the sub-chamber. Preferably, the at least one notch is straight along its length. Alternatively, the at least one notch may be curved. The at least one notch may be disposed at an oblique angle.

The notch or notches help to generate swirl within the chamber, supporting the outward spray of water droplets from the outlet. The angle and shape of the or each notch vary the properties of the swirl, particularly its direction and speed. A pair of opposing lateral holes may be provided. A pair of opposing notches may be provided. In one embodiment, the opposing lateral holes may be offset from one another on the deflector about its longitudinal axis. In other words, the holes may not be in-line with one another. Preferably, the pair of lateral holes is rotationally offset from the pair of notches. More preferably, the notches are disposed closer to the outlet than the lateral holes. The deflector may have rotational symmetry about its longitudinal axis. Preferably, the rotational symmetry is two-fold rotational symmetry. The swirl of water can therefore be set up on both sides of the deflector at once. The two components of the swirl, i.e. those from each lateral hole, travel in the same direction as the notches are rotationally symmetric. The two components of the swirl meet and interfere constructively to reinforce the overall swirl within the chamber. The housing may include means to connect to the tap at its water-dispensing end. Preferably, the housing includes an external male threaded portion to screw into a correspondingly threaded portion of the tap. More preferably, the nozzle is designed to fit inside a tap with a minimal proportion of the housing protruding from the tap. The proportion to which the housing protrudes may be 30 mm or less. The nozzle may be miniaturised sufficiently to fit to the tap so that the housing does not protrude.

At least one groove may be provided in the sub-chamber for directing water to the outlet. The or each groove may spiral towards the outlet. Preferably, two grooves are provided. More preferably, the two grooves begin on opposing sides of the sub-chamber and spiral towards the outlet. The two grooves may be substantially rotationally symmetric.

The groove(s) in the sub-chamber impart swirl to the water flowing towards the outlet. This allows the spray pattern to be controlled at both very high and very low water pressure. It is also beneficial from a manufacturing perspective when moulding the nozzle.

The inlet may include a filter having a plurality of apertures provided therethrough. Preferably, each aperture is 2 mm in diameter or less. The filter prevents water-borne debris from entering the deflector, which might adversely affect its operation. The filter is a simple component to remove and clean when needed. Scale deposition from hard water will also be more prevalent on the large surface area of the filter apertures, i.e. prior to the outlet, which prolongs the typical lifetime of the nozzle by minimising the rate at which the outlet becomes scaled. The apertures are small enough to prevent macroscopic detritus from passing, but not so small that water flow is substantially impeded. The deflector may have one or more chamfered edges. Preferably, the entrance to the channel is chamfered to improve the flow of water through the channel in use. More preferably, the base of the deflector is chamfered around its periphery to improve the flow of water within the sub-chamber in use. By chamfering the edge at the entrance of the channel, water is guided into the channel in use. By chamfering the edge of the base of the deflector, the base does not significantly disrupt (or introduce turbulence into) the swirl of water within the sub- chamber. One or more of the deflector, the internal chamber, the sub-chamber, and/or the outlet may have hydrophobic properties to assist atomisation of the flow of water in use.

According to a second aspect of the present invention, there is provided an atomiser nozzle for restricting and atomising a flow of water from a tap, the atomiser nozzle comprising a housing having an inlet, an outlet, and an internal chamber in communication with the inlet at one end and the outlet at its other end, wherein

the internal chamber is substantially cylindrical and domed at the outlet end, the outlet being provided by an aperture through the dome;

a deflector is disposed within the internal chamber, the deflector being substantially cylindrical and including a channel disposed along its length and at least one lateral aperture, the channel extending partway through the deflector and intersecting the at least one lateral aperture; and

an annular space is disposed between the exterior of the deflector and interior wall of the internal chamber, which communicates with the dome; in use, the flow of water swirling through the annular space and accelerating towards the outlet as it passes through the dome.

The atomiser nozzle of the second aspect of the invention may include any feature or combination of features of the atomiser nozzle of the first aspect of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which:

Figure 1 shows a perspective view of an atomiser nozzle according to the invention; Figure 2 shows a cross-sectional side view of the atomiser nozzle of Figure 1;

Figure 3 shows an exploded perspective view of the atomiser nozzle of Figure 1;

Figure 3 A shows an enlarged perspective view of a deflector in isolation from the atomiser nozzle of Figure 1 ;

Figure 4 shows a cross-sectional perspective view of the atomiser nozzle of Figure 1;

Figure 5 shows an exploded perspective view of a second embodiment of an atomiser nozzle according to the invention, showing a housing, a deflector, a washer and a filter;

Figure 6A shows a cross-sectional side view of the atomiser nozzle of Figure 5;

Figure 6B shows a cross-sectional perspective view of the atomiser nozzle of Figure 5, without the deflector;

Figure 7A shows bottom perspective view of the deflector from the atomiser nozzle of Figure 5; Figure 7B shows a cross-sectional side view of the deflector of Figure 7 A; Figure 8 shows a plan view of the atomiser nozzle of Figure 5, without the deflector or filter; Figure 9 shows a side cross-sectional view of a third embodiment of an atomiser nozzle according to the invention; and

Figure 10 shows a side cross-sectional view of a fourth embodiment of an atomiser nozzle according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to Figures 1 to 4, an atomiser nozzle for a tap is indicated generally at 10. The nozzle 10 includes a housing 12, an inlet indicated generally at 14, and an outlet (or outlet aperture) 16. The inlet 14 is fluidly connected to the outlet 16 by an internal chamber 18. The internal chamber 18 is substantially cylindrical. The housing 12 also includes a dome (or domed section) 20. The outlet 16 passes through the centre of the dome 20. The outlet 16 is a narrow passage of around 0.3 mm diameter. It will be appreciated that other diameters may be used in alternate embodiments of nozzle.

The nozzle 10 includes an external threaded portion 12a on the housing 12 to securely connect to a tap. An outer washer 26 is seated on an outer portion of the housing 12 below the threaded portion 12a (as viewed) to distribute force from the housing 12 onto the tap when screwed together, creating a watertight seal in use. The nozzle 10 further includes a filter 28 across the inlet 14. The filter 28 has a plurality of holes 28a through its central portion. The holes 28a are all around 1 mm in diameter, although it will be appreciated that other diameters of hole may be used in alternate embodiments. The filter 28 is disposed against an inner washer 30. Screwing the nozzle 10 onto a tap compresses the filter against the inner washer 30 to prevent water leaking around the filter 28 in use.

The nozzle 10 further includes a deflector 22. The deflector 22 is disposed within the internal chamber 18. The deflector 22 is substantially cylindrical to fit within the substantially cylindrical chamber 18. The deflector is rotationally symmetric about its longitudinal axis, having two-fold rotational symmetry in this embodiment. As seen in Figure 3 A, the deflector 22 includes a circumferential lip 32. The internal chamber 18 has a corresponding, but slightly narrower, circumferential ridge 32a (as seen in Figure 4). The lip 32 sits against the ridge 32a when the deflector 22 is located within the internal chamber 18.

An annular space or gap 24 is provided between a lower portion of the deflector 22 and the internal chamber 18. More specifically, a side wall 23 of the deflector 22 lies substantially out of contact with the internal chamber 18. The internal chamber 18 has an interior wall 18a in close proximity to the side wall 23 of the deflector 22. The distance between the interior wall 18a and side wall 23 is substantially around 0.19 mm. In other words, the annular space 24 spans 0.19 mm. It will be appreciated that other sizes of gap between the deflector and internal chamber may be used in alternate embodiments of nozzle.

The deflector 22 includes a channel 34, and two lateral apertures 35. The lateral apertures 35 lie opposite one another to maintain the rotational symmetry of the deflector 22. The entrance to the channel has a chamfered edge 34a. The channel 34 extends downwardly partway through deflector 22, from an open end nearest the inlet 14 to a closed end nearest the outlet 16. The channel 34 then branches perpendicularly into the two lateral apertures 35 disposed in the side wall 23. Each lateral aperture 35 narrows from where it intersects the channel 34 to the side wall 23, such that each aperture 35 is tapered. The diameter of the channel 34 is greater than the individual diameter of either lateral aperture 35. However, the cross-sectional area of the channel 34 is less than the sum of the cross-sectional areas of each lateral aperture 35. In this embodiment, each lateral aperture 35 has a diameter of 2 mm at the side wall 23, but other embodiments may have alternate sizes of aperture 35.

In the present embodiment, the lateral apertures 35 are provided through the side wall 23 directly opposite each other, each having an axis that intersects the longitudinal axis of the deflector 22 perpendicularly. In other embodiments, each aperture 35 may be provided at an angle through the side wall 23, to impart greater swirl to a flow of water passing therethrough. In other words, the apertures 35 may each be provided along an axis that does not intersect the longitudinal axis of the deflector 22 perpendicularly, or indeed intersect it at all if offset to either side of the deflector 22.

The deflector 22 also includes a base 22a with a chamfered peripheral edge 22b. The base 22a of the deflector 22 faces the outlet 16. The base 22a is spaced from the outlet 16 to provide a sub-chamber 38 within the internal chamber 18. The sub-chamber 38 is substantially hemispherical in this embodiment. The interior surfaces of the hemispherical sub-chamber 38 are the internal surface of the dome 20 and the base of the deflector. The annular space 24 leads into the hemispherical sub-chamber 38 without obstruction, ensuring water flow transitions smoothly between the space 24 and sub-chamber 38 in use.

The deflector 22 further includes two notches (or slots) 36. The notches 36 are each cut obliquely into the base 22a of the deflector, best seen in Figure 3A. Each notch 36 is straight along its length, although it will be appreciated that the or each notch may be curved in alternate embodiments. In this embodiment, each notch is around 0.45 mm in width and around 2.4 mm in length. The notches 36 are cut at an angle such that the two-fold rotational symmetry of the deflector 22 is maintained. The pair of notches 36 are rotationally offset from the pair of lateral apertures 35 by substantially around 90 degrees. It will be appreciated that the notches 36 may be offset by another angle in an alternate embodiment of the nozzle.

In use, the nozzle 10 is screwed, via its male thread 12a, into a tap with a corresponding female thread. This establishes a watertight seal so that, when water is dispensed from the tap, the flow path of the water must take it from the inlet 14 to the outlet 16 through the deflector 22. When the tap is turned on, water enters the inlet 14 and is filtered through the filter 28 to remove any water-borne particulate matter and disrupt the coherent stream of water into multiple flows. Water then enters the internal chamber 18, and flows over the chamfered edge 34a into the channel 34 of the deflector 22. At the closed end of the channel 34, the water is redirected perpendicularly to either side through the lateral apertures 35. The flow then engages the interior wall of the chamber 18, flowing around the annular space 24. The flow of water is substantially disrupted when it first impacts the closed end and then impacts against the interior wall, and swirls downwardly around the annular space 24 under pressure. The notches 36 in the base of the deflector influence the fluid dynamics within the internal chamber 18, i.e. the annular space 24 and sub-chamber 38, to set up and maintain a swirl of water when the nozzle is in use.

Water exits the annular space 24 and swirls around the hemispherical chamber 38. The smooth transition between the space 24 and chamber 38 ensures that flow does not detach substantially from the internal surface of the dome 20, and also helps accelerate the flow towards the outlet 16. Water then swirls around and into the outlet aperture 16 at the centre of the dome 20. The swirl of water disperses outwardly from the outlet 16 at the centre of the dome 20 in a mist or spray, expanding in an approximately conical manner. The cone of droplets is a hollow spray cone. The range of conical angles may be between 20° and 60°. The very narrow outlet 16 thus causes the swirl of water to split into a multitude of small droplets at its edge on exit, atomising the flow, and also substantially restricts the rate at which water can exit the tap at a given pressure, saving water. The sub-chamber 38 also acts as a reservoir into which water can accumulate.

The large number of droplets have a high combined surface area relative to their volume, and a minimal individual splash distance as a result of their low mass. A user washing their hands, for example, would place their hands beneath the nozzle in use and receive a thin film of water across their hands, rather than a large stream only a portion of which ever contacts their skin. This film of water is sufficient for then lathering soap on the user's hands without wasting large volumes of water, and subsequently using a similarly small volume of water to rinse the soap away.

Referring now to Figures 5 to 8, a second embodiment of an atomiser nozzle is indicated generally at 110. The nozzle 110 has similar features to the first embodiment of nozzle, and the following description focuses mainly on the different features. The nozzle 110 includes a housing 112, an inlet indicated generally at 114, and an outlet (or outlet aperture) 116. The inlet 114 is fluidly connected to the outlet 116 by an internal chamber 118. A deflector 120 is disposed within the internal chamber 118. The side of the deflector 120 is slightly spaced from a wall 118b of the internal chamber 118, forming an annular gap 119. The bottom of the deflector 120 and the outlet end of the internal chamber 118 define a sub-chamber 118a. A filter 122 is provided at the inlet end of the internal chamber 118. The filter 122 is a push-fit component, having an undercut 122a which fits overs and engages a correspondingly shaped portion of the housing 112. A washer 124 fits onto the housing 112 for fitting the nozzle securely to a tap.

The sub-chamber 118a narrows (or tapers) gradually from the base of the deflector 120 to the outlet end of the internal chamber 118. The sub-chamber 118a includes two grooves 126a, 126b, best seen in Figure 8. The grooves 126a, 126b spiral inwardly from the edge of the sub-chamber 118a towards the outlet 114. Each groove 126a, 126b is rotationally offset from the other by around 180 degrees. The grooves 126a, 126b are rotationally symmetric. The grooves 126a, 126b begin adjacent to the annular gap 1 19 for swirling water as it enters the sub-chamber 118a. The deflector 120 is a push-fit component that fits into the internal chamber 118. The deflector 120 includes a circumferential lip 120a that engages a corresponding ridge 118c in the internal chamber 118. Pushing the deflector 120 down into the internal chamber 118 allows the lip 120a and ridge 118c to engage one other, fixing the deflector 120 securely inside the chamber 118.

The deflector 120 includes chamfered bottom edge 120b. The chamfered edge 120b lies against the slanting wall of the sub-chamber 118a. The chamfered edge 120b overlies portions of the grooves 126a. 126b. The deflector 120 includes a central channel 128 which ends partway along the length of the deflector 120. The closed end of the channel 128 narrows similarly to the sub-chamber 118a. Two lateral apertures 130 are arranged orthogonally to the channel 128, inset from its closed end.

The portion shown of the nozzle 110 comprises three main separate components. These are the housing 112, the deflector 120 and the filter 122. This simplifies the manufacturing process and enables fast automated assembly of the nozzle 110. There are also fewer parts which can fail, unlike nozzles with many different component parts, and fewer portions of the nozzle 110 which can act as bacteria traps. In use, the nozzle 110 is fitted to a tap and water can flow through the filter 122 and inlet 114 to the deflector 120 via the internal chamber 118. Water flow is then redirected through the channel 128 and lateral apertures 130, and enters the annular gap 119, swirling around it. The flow of water is then swirled into the sub-chamber 118a via the grooves 126a, 126b. The flow through each groove reinforces the overall swirl of water in the sub-chamber 118a. The water spirals around the sub-chamber 118a and accelerates towards the outlet 116. The flow of water is then atomised through the outlet 116 in a hollow spray cone. The spray cone angle is relatively independent of the mains system water pressure, so that it remains substantially constant in use, irrespective of water pressure fluctuations. The water saving aspects of the nozzle are the same as the first embodiment.

Figures 9 and 10 illustrate third and fourth embodiments of atomiser nozzles 210, 310 respectively, both being similar to the second embodiment. The shapes of the nozzle housings in these embodiments are customised to fit to different shapes of tap. The deflectors in these embodiments are viewed from an alternate orientation to the first and second embodiments, seen along a common axis of the lateral apertures of the deflector. Note that the sub-chamber in each of the third and fourth embodiments is similar to that of the second embodiment, narrowing to the outlet. However, the sub-chamber in the Figure 10 embodiment is recessed into the body of the nozzle, rather than protruding from it. In Figure 9, part of the housing extends outwardly and encircles the sub- chamber and outlet portion of the nozzle. The modes of operation of the third and fourth embodiments are substantially similar to the second embodiment.

Other embodiments are also envisaged within the scope of the claims. Outlet apertures of alternative diameters are considered for producing smaller or larger droplets of water as needed, with smaller apertures for smaller average droplet sizes (and vice versa). Any combination of lateral holes and notches may be considered for use in the deflector, which may or may not have rotational symmetry. The nozzle may be suitable for use in a shower head, for example, which dispenses water much like a tap. Other forms of filter may be considered, such as a mesh, or a raised filter. The dimensions, shape and orientation of the notches may also vary between embodiments to control the swirl of water through the outlet. The nozzle may not include an outer threaded portion, and may instead be connected directly into a separate adapter already provided on a tap.

The embodiments described above are provided by way of example only, and various changes or modifications will be apparent to persons skilled in the art without departing from the scope of the present invention as defined by the appended claims.




 
Previous Patent: DETECTOR AND METHOD OF OPERATION

Next Patent: ATOMISER NOZZLE