This invention relates generally to pumps and more particularly to priming systems for pumps and trailers for pumping units and other industrial equipment. More specifically, although not exclusively, this invention relates to automated vacuum priming systems for high volume, portable liquid pumps. The invention also relates to a trailer having a detachable base on which pumping units or other industrial equipment is mounted.

When incorporated into a pumping system, a priming unit provides a self-priming function that automatically primes the suction line to the pump for high capacity operation. Pumping systems of this type are often used outdoors, such as for dewatering of flooded zones, quarries, waterways or irrigation, or in factories, power stations, sewerage plants and the like. Such applications present a variety of circumstances that require such pumping systems to operate under varying conditions.

It is known to provide automatic priming units that incorporate a vacuum pump for evacuating air from the suction line to allow fluid to be drawn for the main pump intake. One known issue with conventional vacuum pump priming units is their inability to function when the pumping system is operated both under negative and positive head conditions. Positive head conditions will cause a gas-medium vacuum pump to be flooded with liquid, resulting in damage to the vacuum pump.

US5536147 proposes a self-priming pump system incorporating a pumping unit and a priming unit with a high capacity vacuum pump, which is operated in conjunction with a high-volume centrifugal pump in the pumping unit. The priming liquid level within a well chamber of the priming unit is detected using float switches to control the operation of the vacuum pump. Air drawn through the vacuum pump is then discharged into the atmosphere.

Whilst such known vacuum priming systems function well for their designed purpose, the applicant has observed that they are susceptible to damage if a surge of inlet fluid is experienced and their ability to pump contaminated fluids can be improved. The nature of the components of the system also require periodic maintenance, particularly when they are used for pumping corrosive and/or contaminated liquids and materials. Industrial equipment, such as general purpose pumping units, are often provided in compact, portable configurations. General purpose pumping units, for example, are used outdoors, such as for dewatering of flooded zones, quarries, waterways or irrigation, or in factories, power stations, sewerage plants and the like. Similarly, welding equipment (or indeed several other forms of industrial equipment) are used in various environments. As such, these applications present a variety of circumstances that require such pumping units to be manoeuvrable and versatile.

It is also known to provide trailers within which such industrial equipment is housed, which include wheels and a tongue for attachment to, for example, the trailer hitch of a vehicle. However, wheeled systems can be hazardous in some environments and their storage can present significant issues.

It is therefore a non-exclusive aim of the invention to provide a vacuum priming system, associated pumping system and trailer assembly that overcome, or at least mitigate these and other issues with known systems. It is a further, more general non-exclusive aim of the invention to provide an improved vacuum priming system, associated pumping system and trailer assembly.

Accordingly, a first aspect of the invention provides a vacuum priming system or unit, e.g. for priming a liquid pump, the system or unit comprising a well chamber with an inlet, e.g. for connection with a source of liquid, and an outlet, e.g. for connection with a pump, a vacuum chamber in fluid communication with the well chamber and having an air outlet, a vacuum pump fluidly connected to the air outlet, a sensing means, which may be contactless and/or devoid of exposed moving parts, associated with the vacuum chamber for detecting a liquid level therein and a control means operatively connected to the vacuum pump and to the sensing means, wherein the control means is operable or configured to disable, in use, the vacuum pump when a predetermined liquid level in the vacuum chamber is detected by the sensing means.

The use of a sensing means that is contactless and/or devoid of exposed moving parts for detecting the liquid level reduces the likelihood of damage to the priming means. More particularly, float operated sensing means which are subjected to a sudden surge of liquid into the vacuum chamber could become damaged. In addition, maintenance requirements are reduced by omitting moving parts that would otherwise become contaminated. Furthermore, the applicant has observed that float sensors may provide inadequate response to changing priming liquid levels when the liquid contains debris. This can lead to an inaccurate or delayed response which, in turn, may lead to liquid carryover or inefficient pump system operation.

As used herein, the term "contactless" refers to the ability of the sensing means to detect a liquid level without contacting the liquid. For the avoidance of doubt, the sensing means need not be isolated from the liquid, for example a surface of the sensing means may be exposed to the inside of the vacuum chamber and may therefore be exposed to liquid or other materials contained therein from time to time.

The sensing means may comprise one or more sensors, which may be contactless and/or emit and/or receive mechanical or acoustic and/or electromagnetic waves. The sensing means may comprise an echo-based or reflection-based sensing or measurement means, for example an acoustic, e.g. ultrasonic, or electromagnetic, e.g. microwave or radar, sensing or measurement means. The sensing means may comprise a transducer and/or a transceiver or separate transmitter and receiver.

Preferably, the contactless sensing means comprises an acoustic or electromagnetic sensor. More preferably, the contactless sensing means comprise an ultrasonic sensor. The applicant has determined that ultrasonic sensors are particularly suited to applications in which the liquid to be pumped contains contaminants, such as solid waste and the like, e.g. sewerage.

Additionally or alternatively, the contactless sensing means may comprise a microwave sensor. Additionally or alternatively, the sensing means may comprise other contactless sensing means, such as optical sensing means. Additionally or alternatively, the sensing means may be devoid of exposed moving parts and/or comprise a conductive, capacitive and/or pneumatic sensing means, e.g. in which any active or moving component(s) thereof are isolated or at least shielded from the liquid to be pumped.

The well chamber may be adjacent and/or below, in use, the vacuum chamber. The sensing means may be mounted to and/or in the vacuum chamber, for example an upper portion of the vacuum chamber or a portion of the vacuum chamber that is remote from the well chamber. Additionally or alternatively, the sensing means may be configured to emit, in use, a signal, for example downwardly. The sensing means may be configured to emit, in use, a signal toward a vertical fluid passageway connecting the well chamber to the vacuum chamber. The signal emitted may comprise an acoustic or electromagnetic signal.

The system or unit, hereinafter system, may comprise a baffle means, such as one or more baffles, which may be in or between the well chamber and/or vacuum chamber. The baffle means, e.g. at least one of the baffles, may be in or on or adjacent the or a fluid passageway connecting the well chamber to the vacuum chamber. The baffle means, e.g. one or more or at least one of the baffles, may be configured such that a liquid flowing, in use, from the well chamber into the vacuum chamber is forced through a non-linear or tortuous path for stabilising a liquid entering the vacuum chamber from the well chamber.

The baffle means, e.g. one or more baffles, may comprise a plate, e.g. first plate, which may at least partially obstruct the flow passageway. The plate may be substantially perpendicular to the primary flow direction through the flow passageway, e.g. such that liquid flowing, in use, from the well chamber into the vacuum chamber is forced around the periphery of the first plate.

The baffle means, e.g. one or more baffles, may comprise a plate, e.g. a further or second plate, which may have an aperture, e.g. therethrough. The further or second plate may be spaced from the plate or first plate and/or may be substantially aligned therewith, e.g. such that liquid flowing, in use, through the aperture is forced around the periphery of the first plate.

The first and/or second plates may be in, e.g. mounted in, the vacuum chamber or well chamber. The first plate may be positioned between the fluid passageway and the second plate, e.g. such that liquid which flows, in use, between the fluid passageway and the aperture in the second plate is forced around the periphery of the first plate to flow from the well chamber into the vacuum chamber.

The aperture in the second plate may be smaller than the periphery of the first plate, e.g. such that liquid flowing from the well chamber into the vacuum chamber to flow along at least part of the first plate. Additionally or alternatively, the periphery of the first plate may be larger than the fluid passageway, e.g. such that liquid flowing from the well chamber into the vacuum chamber to flow along at least part of the first plate.

The vacuum pump may comprise an air inlet, which may be fluidly connected to the air outlet of the vacuum chamber. The system may comprise a valve means, which may be between the vacuum pump and the vacuum chamber, e.g. for selectively opening and/or closing fluid communication therebetween. The control means may be operable or configured to close, in use, the valve means when, as or after the vacuum pump is disabled or when the or a further predetermined liquid level in the vacuum chamber is detected by the sensing means. The predetermined liquid level at which the control means is operable or configured to disable the vacuum pump may comprise a first predetermined liquid level or threshold. The predetermined liquid level at which the control means is operable or configured to close the valve means may comprise a different, e.g. a second, predetermined liquid level or threshold, preferably one which is higher, in use, than the first predetermined liquid level or threshold.

The control means may be configured to enable or initiate or start, in use, the vacuum pump, e.g. when the sensing means detects a liquid level in the vacuum chamber that is below the predetermined liquid level, e.g. the first threshold. The vacuum pump may comprise a clutch means, e.g. for connection with an engine. The clutch means may comprise an electronic clutch. The control means may be operable or configured to disable the vacuum pump via the clutch means, e.g. by disengaging the clutch. The control means may be operable or configured to enable or initiate or start the vacuum pump via the clutch means, e.g. by engaging the clutch or by causing the clutch to engage or couple the vacuum pump or a prime mover or shaft thereof to the engine or a prime mover or shaft thereof.

The valve means may comprise one or more valves, for example one or more valves, such as solenoid or servo valves. The vacuum pump may comprise a dry running rotary vane vacuum pump. Advantageously, the vacuum pump may comprise a dry scroll vacuum pump. Dry scroll vacuum pumps are preferable because dry running rotary vane pumps can occasionally emit graphite dust.

The vacuum pump may comprise an air outlet, which may be connected or connectable to the air intake of an engine, e.g. an internal combustion engine. Another aspect of the invention provides a vacuum priming system or unit, e.g. for priming a liquid pump, the system or unit comprising a well chamber with an inlet, e.g. for connection with a source of liquid, and an outlet, e.g. for connection with a pump, a vacuum chamber in fluid communication with the well chamber and a vacuum pump with an air outlet and an air inlet fluidly connected to an air outlet of the vacuum chamber, wherein the air outlet of the vacuum pump is connectable, e.g. directly or indirectly, to the air intake of an internal combustion engine.

The vacuum pump may comprise an outlet connection means or coupling means, for example an outlet connection, connector or coupling. The system or unit, hereinafter system, may comprise a pipe in fluid communication with or providing the outlet of the vacuum pump. The pipe may comprise the connection or coupling means.

The priming system may comprise and/or be fluidly connected to an engine, e.g. an internal combustion engine. The air outlet of the vacuum pump may be in fluid communication with an air intake of the engine. The engine may be operatively connected, for example via the or a clutch means, to the vacuum pump, e.g. for driving the vacuum pump. The engine may comprise an internal combustion engine, for example a diesel internal combustion engine.

By connecting the outlet of the vacuum pump to the air intake of the engine, the contaminants present in the air expelled from the vacuum pump are burned within the engine, killing any bacteria and the like.

The system may comprise an air baffle means, e.g. one or more baffles, which may be between the air outlet of the vacuum pump and the air intake of the engine. The system may comprise a baffle chamber within which the air baffle means is received, mounted or housed. The baffle chamber may comprise an inlet, which may be fluidly connected to the outlet of the vacuum pump. The baffle chamber may comprise an outlet, which may be fluidly connected to the air intake of the engine. The baffle means may cause or force air flowing, in use, from the vacuum pump to the air intake of the engine to flow along a nonlinear or tortuous path. The baffle means may comprise one or more baffle plates, for example a cascade of baffle plates. At least some of the baffle plates may be, or have portions that are, substantially parallel to one another. At least some of the baffle plates may be offset relative to one another, e.g. to create a non-linear or tortuous flow path therebetween and/or between the inlet and outlet of the baffle chamber. Another aspect of the invention provides a pumping system or unit comprising a priming system as described above. The pumping system or unit, hereinafter system, may comprise a pump, e.g. a liquid pump. The priming system may comprise or be operatively connected to an engine, e.g. an internal combustion engine, which may be operatively connected to the pump and/or to the vacuum priming system, e.g. for driving the pump and/or priming system.

The pump may, but need not, comprise a centrifugal pump. The pump may have an inlet and/or an outlet. The inlet of the pump may be fluidly connected to the outlet of the well chamber. The pumping system, pump or pump outlet may comprise a non-return valve, which may enable liquid to flow, in use, out of the pump outlet and/or inhibit or prevent liquid from flowing into the outlet. The non-return valve may comprise a flap, which may be flexible and/or may be formed of a plastics or composite material. The pumping system may comprise an engine operatively connected to the liquid pump, for example directly or via a gearbox and/or clutch means, which may comprise an electronic clutch.

The pumping system may comprise a housing within which the pumping system or one or more, e.g. all, of the priming system, pump and/or engine is or are housed. The housing may comprise a base, for example on which the pumping system, priming system, pump and/or engine may be placed, mounted and/or secured.

The base may comprise a skid or pallet and/or may include one or more, e.g. a pair, of slots. The slots may extend through a lower portion of the base, for example below or beneath, in use, the pumping system, priming system, pump and/or engine.

Additionally or alternatively, the base may comprise one or more wheels, e.g. one or more pairs of wheels, and/or a connection or coupling means, for example a connector or coupling. The base may comprise a trailer or trailer assembly, which may be connectable or couplable, e.g. via the connection or coupling means, to a vehicle for towing.

Another aspect of the invention provides a method of priming a liquid pump comprising drawing air from the well chamber of a pumping system through a vacuum chamber using a vacuum pump until a predetermined liquid level in the vacuum chamber is detected by a sensing means, which sensing means may be contactless and/or devoid of exposed moving parts.

Another aspect of the invention provides a method of sterilising air emitted from the vacuum priming system of a pumping system, the method comprising drawing air from the well chamber of the pumping system and introducing it into the air intake of an internal combustion engine.

Another aspect of the invention provides a trailer or trailer assembly comprising a priming or pumping system as described above.

The trailer or trailer assembly may comprise a housing, for example within which is received, mounted and/or secured a priming system or pumping system as described above.

Another aspect of the invention provides a trailer assembly comprising a subframe and a platform, crate or container detachably mounted to the subframe.

The provision of a detachable platform, crate or container enables industrial equipment mounted thereon or therein to be removed and placed on a substrate at a site of use or stored when the equipment is not in use.

The platform, crate or container may comprise wheels and/or a tongue, e.g. for coupling the trailer to a vehicle. The assembly may comprise one or more catch mechanisms, e.g. for releasably securing the platform relative to the subframe. The or each catch mechanism may be retractable, for example to permit the platform, crate or container to be slid, in use, relative to the subframe, e.g. thereby to disengage a slidable connection therebetween.

Another, more specific aspect of the invention provides a trailer assembly comprising a subframe with wheels and a tongue for coupling the trailer to a vehicle, a platform detachably mounted to the subframe and a catch mechanism for releasably securing the platform relative to the subframe, wherein the catch mechanism is retractable to permit the platform to be slid, in use, relative to the subframe thereby to disengage a slidable connection therebetween. The slidable connection may be at or adjacent one end of the platform, crate or container. The or each catch mechanism may secure a portion of the platform, crate or container between the slidable connection and the opposite end of the platform, crate or container. The assembly may comprise a pair of wheels, which may rotate about a common or substantially coaligned axis. The or each catch mechanism may secure a portion of the platform that is adjacent the common axis or the substantially coaligned axes of the wheels. The at least one catch mechanism may comprise a pair of catch mechanisms, one of which may secure a respective side portion of the platform, e.g. adjacent the common axis or the substantially coaligned axes of the wheels.

Additionally or alternatively, the slidable connection may comprise a tab or tongue, which may engages a ledge, recess or slot. The subframe may comprise the tab, which may be adjacent the tongue. The platform, crate or container may include a cross member, e.g. along its front. The cross member may comprise a recess, for example on its lower surface, which may be for receiving part of the tongue. The cross member may comprise a ledge, e.g. for engaging the tab.

The catch may be retractable, for example to permit the platform, crate or container to be pivoted relative to the subframe. The platform, crate or container may be pivotable, for example from a first orientation to a second orientation. The slidable movement between the platform, crate or container and the subframe may be prevented, for example in the first orientation. The slidable movement between the platform, crate or container and the subframe may be permitted, for example in the second orientation.

The sliding movement between the platform, crate or container and the subframe may be prevented by stop means, e.g. when the platform, crate or container is in the first orientation. Additionally or alternatively, the stop means may comprise a projection, e.g. on one of the platform, crate or container and subframe. The stop means may additionally or alternatively comprise a recess or slot, e.g. in the other of the platform, crate or container and subframe. The projection may be receivable within the recess or slot.

Additionally or alternatively, the stop means may be provided by a cross-member of the subframe, which may extend between the wheels. The platform, crate or container may comprise a recess, e.g. on or in a lower surface thereof, e.g. within which the cross-member of the subframe may be receivable. The platform, crate or container may comprise one or more lifting elements, for example lifting members, frames or frame sections. The lifting elements may be mounted or secured to one or more peripheral portions of the platform, crate or container or, in the case of a crate or container, to a side wall or top wall thereof. The platform, crate or container may comprise a longitudinal dimension or axis and/or a lateral dimension or axis and/or a vertical (in use) dimension or axis. The or at least one of the lifting elements may be spaced from the centre of the platform, crate or container, for example the longitudinal or lateral or vertical centre thereof. The or at least one of the lifting elements is preferably above the vertical centre of the platform, crate or container.

The or at least one of the lifting elements may be spaced from the longitudinal or lateral centre of the platform, crate or container, e.g. such that a lifting force applied, in use, to the lifting element(s) causes the platform, crate or container to pivot from the first orientation to the second orientation.

The slidable connection may be at or adjacent a first longitudinal end of the platform, crate or container. The catch mechanism may secure a portion of the platform, crate or container between the slidable connection and a second longitudinal end of the platform, crate or container. Preferably the catch mechanism secures a portion of the platform, crate or container that is substantially central or near the centre of the platform.

The catch mechanism may comprise a sprung projection, which may be comprised in or of or mounted on one of the subframe and the platform, crate or container. The sprung projection may engage an abutment or ledge, e.g. comprised in or of the other of the subframe and the platform, crate or container. Preferably, the sprung projection is comprised in or of or mounted to the subframe and the abutment or ledge is comprised in or of or mounted to the platform, crate or container.

The projection may comprise a tapered surface, which may be configured such that the projection is urged, in use, toward a retracted position, e.g. when a force is applied perpendicularly with respect to the sprung movement of the projection. The projection may be urged, in use, toward the retracted position when the platform, crate or container is lowered onto the subframe and may snap to a deployed and/or engaged position when the abutment or ledge is aligned therewith. The catch mechanism may comprise an actuator handle, which may be operatively connected to the sprung projection, e.g. to enable the catch to be rectracted. Additionally or alternatively, the catch mechanism may comprise another actuation means, for example a cable and/or lever mechanism. The actuation means may be manual or automatic, for example it may be actuated by a manual application of force or by a motorised means.

The platform, crate or container may comprise a pair of slots, which may extend therethrough, e.g. for receiving forks of a forklift truck. The slots may extend laterally through the platform or through a base of the crate or container and/or may be in or through a lower portion of the platform or a lower portion of the base of the crate or container. The platform or the base of the crate or container may comprise a skid or pallet. Preferably, the platform or the base of the crate or container comprises a metallic, e.g. steel such as stainless steel, or rigid plastics material.

The platform may comprise a housing or enclosure thereon, e.g. mounted and/or secured thereon. It will be appreciated that such a platform may comprise or be described as a crate or container. Alternatively, the assembly may comprise a crate or container that includes the platform.

The assembly may comprise a pumping system or unit, for example in the housing, enclosure, crate or container. Additionally or alternatively, the assembly may comprise other industrial equipment, such as welding equipment.

Another aspect of the invention provides a pumping system comprising a trailer assembly as described above.

Another aspect of the invention provides a method of detaching the platform, crate or container of a trailer assembly from a subframe thereof, the method comprising retracting a catch mechanism securing the platform, crate or container to the subframe to permit sliding movement therebetween and sliding the platform, crate or container relative to the subframe to disengage a slidable connection therebetween.

For the avoidance of doubt, any of the features described herein apply equally to any aspect of the invention. For example, the pumping system may comprise any one or more features of the priming system relevant thereto or vice versa and the trailer assembly may comprise any one or more features of the pumping system and vice versa. Additionally, the method may comprise any one or more features or steps relevant to one or more features of the priming system, pumping system or trailer assembly or vice versa.

For purposes of this disclosure, and notwithstanding the above, it is to be understood that the control means described herein may comprise one or more controller(s), control unit(s) and/or control module(s) each of which may comprise a control unit or computational device having one or more electronic processors. The controller may comprise a single control unit or electronic controller or alternatively different functions of the control of the system or apparatus may be embodied in, or hosted in, different control units or controllers or control modules. As used herein, the terms "control unit" and "controller" will be understood to include both a single control unit or controller and a plurality of control units or controllers collectively operating to provide the required control functionality. A set of instructions could be provided which, when executed, cause said controller(s) or control unit(s) or control module(s) to implement the control techniques described herein (including the method(s) described herein). The set of instructions may be embedded in one or more electronic processors, or alternatively, may be provided as software to be executed by one or more electronic processor(s). For example, a first controller may be implemented in software run on one or more electronic processors, and one or more other controllers may also be implemented in software run on or more electronic processors, optionally the same one or more processors as the first controller. It will be appreciated, however, that other arrangements are also useful, and therefore, the present invention is not intended to be limited to any particular arrangement. In any event, the set of instructions described herein may be embedded in a computer-readable storage medium (e.g., a non-transitory storage medium) that may comprise any mechanism for storing information in a form readable by a machine or electronic processors/computational device, including, without limitation: a magnetic storage medium (e.g., floppy diskette); optical storage medium (e.g., CD-ROM); magneto optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g., EPROM ad EEPROM); flash memory; or electrical or other types of medium for storing such information/instructions.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. For the avoidance of doubt, the terms "may", "and/or", "e.g.", "for example" and any similar term as used herein should be interpreted as non-limiting such that any feature so-described need not be present. Indeed, any combination of optional features is expressly envisaged without departing from the scope of the invention, whether or not these are expressly claimed. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a schematic representation of a pumping system according to an embodiment of the invention;

Figure 2 is a perspective view of the pump and priming system of the pumping system of Figure 1 ;

Figure 3 is a side view of the pump and priming system of Figure 2 from the inlet side;

Figure 4 is a bottom view of the pump and priming system of Figure 2;

Figure 5 is a front view of the pump and priming system of Figure 2 from the outlet side;

Figure 6 is a rear view of the pump and priming system of Figure 2 showing the baffle chamber;

Figure 7 is a side view of the well and vacuum chambers of the priming system of Figure 2 from the inlet side;

Figure 8 is a section view through line A-A of Figure 7; Figure 9 is a side view of the pump end of the pump and priming system of Figure 2; Figure 10 is a section view through line B-B of Figure 9;

Figure 1 1 is a section view through the baffle chamber of the pump and priming system of Figure 2;

Figure 12 is a perspective view of a trailer within which the pumping system of Figure 1 is housed;

Figure 13 is perspective view of a trailer assembly according to an embodiment of the invention;

Figure 14 is a side view of one of the catch mechanisms of the trailer assembly of Figure 13;

Figure 15 is a section view through the catch mechanism of Figure 14;

Figure 16 is a plan view of the underside of the trailer assembly of Figure 13; and

Figure 17 is a side view of the trailer assembly of Figure 13.

Referring now to Figure 1 , there is shown a pumping system 1 including a priming system 2, a pump 3, an internal combustion engine 4 and a controller 5. In this embodiment, the engine 4 is diesel-fuelled and includes an air intake 40.

As shown more clearly in Figures 2 to 6, the pumping system 1 also includes a gearbox 6 with a bracket 60, an input shaft 61 and a pulley 62 mounted to the end of the shaft 61 for rotation therewith. The priming system 2 includes a well chamber 20, a vacuum chamber 21 above and fluidly connected to the well chamber 20, a contactless sensor 22 mounted at the top of the vacuum chamber 21 , a baffle chamber 23 and a vacuum pump 24 fluidly connecting the baffle chamber 23 to the vacuum chamber 21. A solenoid valve 7 is located in the pipework 70 that connects an outlet 21a of the vacuum chamber 21 to an inlet 24a of the vacuum pump 24. An outlet 24b of the vacuum pump 24 is connected to an inlet 23a (see Figure 11) of the baffle chamber 23 by pipework 71. An outlet 23b of the baffle chamber 23 is connected to the air intake 40 of the engine 4 by pipework 72 (see Figure 1).

The well chamber 20, illustrated more clearly in Figures 7 and 8, is hollow and substantially cylindrical and extends along a horizontal axis. The well chamber 20 includes a flanged inlet 20a for connection with an inlet pipe (not shown), an intermediate fluid passageway 20b in fluid communication with the bottom of the vacuum chamber 21 and a flanged outlet 20c connected to and feeding an inlet 30 of the pump 3. A primary flow path Pi extends from the inlet 20a of the well chamber 20 to the outlet 20c. A secondary flow path P2 extends perpendicularly with respect to the primary flow path Pi , through the intermediate fluid passageway 20b and into the vacuum chamber 21.

The vacuum chamber 21 is also hollow and cylindrical, but it extends along a vertical axis. The vacuum chamber 21 includes an outlet 21 a at its top and a base plate 21 b with a circular aperture 21 c therethrough. The aperture 21c is smaller than the intermediate fluid passageway 20b such that the base plate 21 b restricts (e.g. functions as a baffle) to flow entering the vacuum chamber 21 from the well chamber 20. Moreover, two baffle plates 25, 26 are housed within the vacuum chamber 21 and lie parallel to the base plate 21 b.

A first baffle plate 25, is mounted to the base plate 21 b and spaced therefrom by four equally spaced pillars 27. The first baffle plate 25 is circular in plan, is aligned with and is larger than, i.e. has a periphery that extends beyond, the aperture 21c in the base plate 21 b. The pillars 27 are spaced equally about the periphery of the aperture 21c. A second baffle plate 26 is mounted above the first baffle plate 25 and is secured about its periphery to the inner circumference of the vacuum chamber 21. The second baffle plate 26 includes an aperture 26a, which is also circular in plan, is aligned with and smaller than the first baffle plate 25.

Accordingly, liquid flowing from the well chamber 20 into the vacuum chamber 21 is forced to flow through the aperture 21 c in the base plate 21 b and to snake around the periphery of the first baffle plate 25 and back through the aperture 26a through the second baffle plate 26. It will be appreciated that the overlap of the plates 21 b, 25, 26 defines the extent to which the liquid is required to flow along and between them, thereby creating a tortuous flow path. Thus, the degree of overlap of the plates 21 b, 25, 26 (i.e. the extent of the difference between the relative size of the first baffle plate 25 relative to the apertures 21 c, 26a) defines the degree of meandering of the flow path. The contactless sensor 22 is an ultrasonic sensor in this embodiment and is mounted to the top of the vacuum chamber 21 with an emitter 22a thereof facing downwardly, toward the second baffle plate 26. It will be appreciated by those skilled in the art that the configuration of the vacuum chamber 21 , in which liquid from the well chamber 20 enters vertically via the baffle plates 21 b, 25, 26, will ensure that the liquid level within the vacuum chamber 21 rises in a relatively stable fashion. This feature, coupled with the use of a contactless sensor, particularly an echo-based or reflection-based sensor and more particularly an ultrasonic sensor, ensures reliable and rapid detection of the level of liquid.

Thus, not only does the invention provide a system that removes, or at least reduces, the likelihood of damage to the priming system 2, but the reliability and response time is improved. The result is a superior system that is less susceptible to damage and more efficient pump operation.

The baffle chamber 23, shown more clearly in Figure 11 , is in the form of a box 23c within which are mounted a series of cascading baffle plates 23d, half of which are mounted on one side of the box 23c while the other half are mounted on the other side thereof. All of the baffle plates 23d slope downwardly and each baffle plate 23d on one side extends between a pair of baffle plates 23d on the other side. The inlet 23a is in a lower part of the box 23c and the outlet 23b is in an upper part of the box 23c. Thus, a flow of air from the inlet 23a to the outlet 23b is forced along a tortuous path, which reduces the noise emitted by the priming system 2.

Referring back to Figures 2 to 6, the vacuum pump 24 is of the dry running rotary vane type and is mounted to the gearbox bracket 60. The vacuum pump 24 has an input shaft 24c to which is mounted an electronic clutch 64, which is connected to the pulley 62 of the gearbox 6 via a belt 63. The clutch 64 is operable to selectively engage the input shaft 24c of the vacuum pump 24 to the shaft 61 of the gearbox 6. The pump 3 is coupled to the gearbox, is a centrifugal pump in this embodiment and includes pump end 31 with an outlet 31a fed by an outlet 32 of the pump 3. The pump end 31 includes an end plate 31 a that is connectable to a discharge pipe (not shown) for discharging a pumped liquid.

As shown more clearly in Figures 9 and 10, the pump end 31 includes a non-return valve 34 in the form of a flap 35 secured along its upper edge to a seating plate 36 by a retaining bracket 37 for selectively covering an aperture 38 through the seating plate 36 to which the pump outlet 32 is bolted. The flap 35 is formed of a flexible composite material in this embodiment to enable it to deform and allow liquid to exit through the aperture 38, but preventing ingress of liquid in the event of a backflow condition. The seating plate 36 is mounted at a 45 degree angle relative to the end plate 31 a with its lower edge aligned with the aperture 38. The flap 35 is positioned such that, when it bends about the retaining bracket 37, its lower edge clears the end plate 31 a to ensure that an outlet flow of liquid is substantially uninhibited.

The air intake 40 of the engine 4 is fluidly connected to the outlet 23a of the baffle chamber

23 by a pipe 23b. When the pumping system 1 is used for pumping unpleasant and/or contaminated liquids that contain particulate matter harmful to individuals or the environment, the exhaust from the vacuum pump 24 may contain airborne contaminants from the liquid being pumped. By connecting the outlet 24b of the vacuum pump 24 to the air intake 40 of the engine 4, such matter is burned away, thereby sterilising the exhaust air to a degree and improving health and safety.

In use, the sensor 22 detects whether the liquid level within the vacuum chamber 21 is at, above or below a predetermined threshold, for example at or just above the second baffle 26. If the liquid level is below the threshold, the controller 5 operates the valve 7 to open fluid communication between the vacuum chamber 21 and the vacuum pump 24. The controller 5 also operates the clutch 64 to couple the input shaft 24c of the vacuum pump

24 to the engine 4 via the input shaft 61 of the gearbox 6. The engine 4 then drives the vacuum pump 24, drawing air from the well chamber 20 through the vacuum chamber 21 to prime the pump 3. Air exiting the outlet 24b of the vacuum pump 24 passes through the baffle chamber 23 and into the air intake 40 of the engine 4, where it passes through the combustion chambers thereof and is burned and expelled into the environment as engine exhaust.

Thus, when the pumping system 1 is used to pump contaminated liquids such as sewerage any bacteria contained therein is killed, thereby sterilising the air. If the pumping system 1 is used to pump volatile fluids, the pipework 72 may be disconnected from the air intake 40 of the engine 4. If the liquid level is above the threshold, the controller 5 operates the clutch 64 to decouple the input shaft 24c of the vacuum pump 24 from the engine 4. The controller 5 also operates the valve 7 to close fluid communication between the vacuum chamber 21 and the vacuum pump 24. Such a situation can be the result of a positive pressure at the inlet 20a of the well chamber 20, for example where the liquid to be pumped is in a storage tank above the pumping system 1. Such a situation also arises if the pump 3 has already been primed and is functioning with a relatively constant supply of liquid.

It is also envisaged that the sensor 22 is operable to detect whether the liquid level within the vacuum chamber 21 is at, above or below a second predetermined threshold. The second threshold may be above the first threshold and may be used by the controller in determining whether to open or close the valve 7. For example, the controller 5 may be configured to decouple the vacuum pump 24 when the liquid level is at or slightly above the second baffle 26, but to close the valve 7 only when the liquid reaches a higher level so as to prevent the vacuum pump 24 from being flooded with the liquid. The controller 5 may be configured to open the valve 7 when the liquid drops below the second threshold. It is also envisaged that the controller 5 and sensor 22 are configured to operate the clutch 64 to engage and disengage at different thresholds and/or to open and close the valve 7 at different thresholds.

The input shaft 61 of the gearbox 6 is coupled directly to the pump 3 in this embodiment, so the pump 3 is also driven simultaneously with the vacuum pump 24. However, it is envisaged that the gearbox 6 could be coupled to the pump 3 via a clutch to enable priming to be carried out prior to engaging the pump 3. In such instances, the controller 5 may be operable to cause the pump 3 to be coupled to and driven by the engine 4 only when the liquid level is detected by the sensor 22 to be above the threshold or some other threshold.

Turning now to Figure 12, the pumping system 1 is incorporated within a trailer 8. The trailer 8 includes a housing 80 within which the pumping system 1 is housed, a base 81 on which the housing 80 and pumping system 1 sit and a pair of wheels 82 rotatably mounted to the base 81 to enable the trailer to be moved along a substrate. The trailer 8 also includes a tongue 83 for coupling to the trailer hitch (not shown) of a vehicle (not shown). The use of a trailer 8 facilitates transportation of the pumping system 1 to a site of use. Referring now to Figures 13 to 17, there is shown a trailer assembly 100 including a subframe 102, a platform 103 detachably mounted to the subframe 102, an enclosure 104 secured to the top of the platform 103 and a pair of catch mechanisms 105 that releasably secure the platform 103 to the subframe 102.

The subframe 102 includes a pair of wheels 120 rotatably mounted to a common axle 121 and a tongue 122 secured at a first of its ends 123 to the centre of the axle 121. The tongue 122 is in the form of a hollow tubular member and includes a dogleg 124 adjacent a second end 125 thereof. The tongue 122 also includes a pair of tabs 126a, 126b secured to the top thereof between the dogleg 124 and the first end 123. One of the tabs 126a, 126b extends along each side of the tongue 122 and parallel thereto.

The platform 103 includes a pair of sides 130 each formed of a C-channel section with flanges 131a, 131 b having upturned edges. The open side of the C-channel section of each of the sides 130 opens outwardly such that the upper flange 131a creates an upper ledge on each side 130 of the platform 103 to which the enclosure 104 is secured. Each side 130 includes a pair of slots 132a, 132b spaced equally from its longitudinal centre for receiving forks (not shown) of a forklift truck (not shown). Each slot 132a, 132b is reinforced by a rib extending outwardly about its periphery to form a reinforcing sleeve 133a, 133b projecting from the central web 134 of the C-channel section.

Each side 130 of the platform 103 also includes an inverted U-shaped slot 134a in its lower surface at its longitudinal centre for receiving the axle 121 of the subframe 102. Each slot 134a is reinforced by a rib extending outwardly about its periphery to form a reinforcing sleeve 134b.

The platform 103 also includes a front 135 and back 136, each of which is also formed of a C-channel section with flanges 135b, 136a, 136b having upturned edges. The C-channel sections of both the front 135 and the back 136 face rearwardly such that the flanges 136a, 136b of the back 136 face outwardly and are exposed whilst those 135b of the front 135 are not. The front 135 includes a reverse U-shaped slot 137 extending from its lower flange 135b into its central web 138 that receives the tongue 120 of the subframe 102. The platform 103 also includes a support floor 139 secured to the top of each of the sides 103, front 135 and back 136. The upturned edge of the lower flange 135b of the front 135 provides a ledge extending rearwardly above which the tabs 126a, 126b extend to provide a sliding engagement between the platform 103 and the subframe 102. More particularly, the tabs 126a, 126b engage the lower flange 135b if the platform 103 is moved upwardly. In order to disengage the tabs 126a, 126b from the lower flange 135b, the platform 103 must be slid backwardly.

However, backward sliding movement of the platform 103 relative to the subframe 102 is prevented because the axle 121 is received within the slot 134a of the sides 130 of the platform 103. Thus, the platform 103 must be pivoted about its front 135 from the orientation shown in the Figures in order to release the slot 134a from the axle 121 before sliding the platform 103 backwardly relative to the subframe 102.

The enclosure 104 in this embodiment is adapted for receiving a pumping system (not shown) and includes a slot 140 extending laterally across its upper wall 141. The slot 140 includes three lifting bars 142 spanning the slot 140 and spaced equally along it. The slot 140 is offset from the longitudinal centre of the enclosure 104, toward the rear thereof. As such, when a lifting force F applied to the lifting bars 142, for example by lifting gear (not shown) such as a hoist or lifting hooks engaging the bars 142, the back 136 of the platform 103 (and therefore the rearmost end of the enclosure 104) pivots about the front 135 as illustrated by arrow P. The enclosure 104 also includes a handle slot 143 on either side at the front thereof for manoeuvring the platform 103 and enclosure 104.

As shown more clearly in Figures 14 and 15, each catch mechanism 105 includes a pin 150 slideably received within a sleeve 151 and urged to a deployed position by a compression spring 152. The pin 150 has a tapered end 150a, which is exposed with the tapered surface facing upwardly when the pin 150 is in the deployed position. The compression spring 152 is captivated between a closed end 151a of the sleeve 151 and the pin 150, which extends out of the other end of the sleeve 151. One end of an L-shaped actuating handle 153 is secured within a hole through an intermediate portion of the pin 150 via a slot 151c in the sleeve 151 by a threaded engagement.

The sleeve 151 is mounted to the subframe 102 by a mounting bracket 154 with the open end 151 a of the sleeve 151 facing the platform 103. The catch mechanism 105 is located and oriented such that a lower surface of the tapered end 150a of the pin 150 engages the upturned end of the lower flange 131 b of the side 130. In this embodiment, a block 155 is secured on the lower flange 131 b of the side 130, which has the same height as the upturned edge of the lower flange 131 b to provide more surface area for the underside of the tapered end 150a to engage when it is in the deployed position.

In use and to remove the platform 103 and enclosure 104, lifting gear (not shown) is secured to the bars 142 and a lifting force F is applied to apply tension to the lifting gear (not shown) and to raise the assembly 1 slightly. The handle 153 is operated to move the pin 150 of each catch mechanism 105 from the deployed position to a retracted position, which releases the platform 103 from the axle 121. The lifting gear (not shown) is then raised further, which causes the back 136 of the platform 103 (and therefore the rearmost end of the enclosure 104) to pivot about the front 135 as illustrated by arrow P in Figure 17.

This causes the slot 134a to clear the axle 121 and the subframe 102 is then manipulated to slide the tabs 126a, 126b backwardly, out of engagement flange 135b of the platform 103. It will be appreciated that the configuration enables this disengagement to be effected by continued raising of the lifting gear (not shown), but this approach is less controllable and therefore less preferable.

Once removed, the platform 103 and enclosure 104 may be placed on a substrate, such as a floor. The slots 132a, 132b enable the platform 103 to function as a skid or pallet, which can be lifted and manoeuvred using a forklift truck (not shown) and the like. Moreover, the enclosure 104 is reinforced in this embodiment, enabling a further platform 103 and enclosure 104 to be stacked thereon. In fact, several platforms 103 and enclosures 104 may be stacked on one another, which facilitates storage considerably. This is particularly useful for storing multiple pumping units effectively, which can be removed from the stack and mounted to a subframe 102 for deployment as required. The handle slots 143 may be used to help stabilise the platform 103 and enclosure 104 as it is manoeuvred.

In order to mount the platform 103 and enclosure 104 onto the subframe 102, a reverse operation is carried out to that outlined above. More specifically, the platform 103 and enclosure 104 are lowered to a position slightly above the subframe 102 in a tilted orientation and the tabs 126a, 126b are inserted into engagement with the flange 135b of the platform 103. The platform 103 and enclosure 104 are then lowered further, supported by the tongue 122 such that they pivot thereabout until the slots 134a of the platform 103 engage with the axle 121 of the subframe 102. As the axle 121 enters the slots 134a, a lower surface of the lower flange 131 b contacts the upper tapered surface of the tapered end 150a of the pin 150, which urges the pin 150 against the spring bias until it aligns with the upturned edge of the lower flange 131 b, when it snap back to a deployed and engaged position.

It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. For example, the trailer assembly 100 may include a pumping system 1 or a priming system 2. Moreover, the trailer 8 shown in Figure 12 may include one or more of the features described in respect of the trailer assembly 100 shown in Figure 13.

The ultrasonic sensor 22 may be replaced or supplemented with any other sensing means that is contactless and/or devoid of exposed moving parts. The sensing means may emit and/or receive mechanical or acoustic and/or electromagnetic waves and/or may be echo- based or reflection-based. The sensing means may be conductive, capacitive, pneumatic, acoustic, e.g. ultrasonic, or electromagnetic, e.g. microwave or radar. The vacuum pump 24 and centrifugal pump 3 may comprise any other suitable design.

The pumping system 1 need not be housed within a trailer 8. The pumping system 1 may be mounted on a skid or pallet, which may include a pair of slots for manipulation using a forklift truck. In such a configuration, the pumping system 1 may be housed within a housing 80 mounted to the skid or pallet.

For the avoidance of doubt, the pumping system 1 described above may be described as a pumping or pump unit 1 and the priming system 2 may be described as a priming unit 2.

The lifting bars 142 of the enclosure 104 may be located at the longitudinal centre. In such instances, the weight distribution of the equipment within the enclosure 104 may be such that the centre of gravity is offset from the longitudinal centre.

In other embodiments, the lifting bars 142 may be located such that the platform 103 and enclosure 104 do not tilt or tilt to a lesser or greater extent than in the described embodiment. It will be appreciated by those skilled in the art that less tilt is preferable when stacking the units 103, 104. Additionally or alternatively, lifting bars 142 may be provided on both sides of the longitudinal centre such that tilting can be effected using one set of the lifting bars 142 and level lifting may be effected using both sets of lifting bars 142.

Additionally or alternatively, the catch mechanism 105 may comprise another actuation means, for example a cable and/or lever mechanism. The actuation means may be manual or automatic, for example it may be actuated by a manual application of force or by a motorised means.

It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.