WO2012024729A1

WO2012024729A1 - Apparatus and method for washing trades equipment

Info

Publication number: WO2012024729A1
Application number: PCT/AU2011/001088
Authority: WO
Inventors: Andrew Crimston; Alexander George Bailey; Wayne Bish
Original assignee: Geosentinel Pty Ltd
Current assignee: Geosentinel Pty Ltd
Priority date: 2010-08-23
Filing date: 2011-08-23
Publication date: 2012-03-01
Anticipated expiration: 2013-02-23

Abstract

A washing apparatus for washing trades equipment, comprising: a supply tank containing a wash fluid in a substantially clean state; a supply pump for supplying the wash fluid from the supply tank to a nozzle for directing the wash fluid at the equipment; a receptacle for collecting the wash fluid in a contaminated state, the wash fluid being contaminated with waste washed from the equipment; a collection tank for holding the wash fluid collected by the receptacle; a return pump for pumping the wash fluid from the collection tank to the supply tank via a return filter for filtering the waste from the contaminated wash fluid thereby returning the wash fluid to its clean state; and a line that the wash fluid flows through. The apparatus further comprising a dosing device for automatically introducing a coagulant into the wash fluid as it flows through the line.

Description

APPARATUS AND METHOD FOR WASHING TRADES EQUIPMENT TECHNICAL FIELD

The present invention relates to a washing apparatus and method for washing contaminated trade tools and other equipment. The present invention is primarily described with reference to an apparatus and method for washing painting equipment such as paint brushes, paint rollers, spray gun nozzles and fittings, paint trays and the like. However, it should be understood that the washing apparatus and method of the present invention could be used to wash other trades equipment, such as that used by concreters, tilers, Tenderers, plasterboard installers and the like.

BACKGROUND

When a painting task is finished or at the end of a working day, many painters clean their tools of the trade such as paint brushes, paint rollers, spray guns, or other equipment, with a water hose in a basin. The water contaminated with waste from the equipment (the water in this contaminated state is known as "wash-water") typically drains from the basin into the sewer or onto the ground. This practice is both detrimental to the environment and a waste of water.

In some jurisdictions it is illegal to allow wash-water used to clean paint equipment and other trades equipment into the sewer. Accordingly professional painters, building sites and the like who generate large amounts of wash-water, employ third party contractors to remove and dispose of wash-water in an environmentally friendly manner. As it is quite expensive to handle such contaminated wash-water, a number of prior art devices and systems are known to separate waste from wash-water, thereby allowing contractors to only cart the waste away from site, and possibly allow for the recycling of the treated water.

One such prior art system is described in AU2004100677 (Enviro Solutions Pty Ltd). This system utilises a basin (upper wash structure) in which paint equipment is washed. A settlement tank is disposed below the basin and is used to catch wash-water. A flocculant is added to the settlement tank for the purposes of separating the wash-water into a sediment of paint solids and relatively clean water. The separation process may take up to 24 hours and results in sediment at the bottom of the settlement tank that may be drawn off for disposal, whilst the separated water may be re-used.

A disadvantage of this prior art systems is that a substantial amount of time must pass before the water in the collection tank can be re-used, due to the time it takes for the waste to settle out of the wash-water.

Another prior art system is described in WO 2010/022455 (Geosentinel Pty Ltd). This apparatus uses at least three tanks so that wash-water collected in one of the tanks may settle by means of flocculant added to the tank, whilst the other two tanks are used to supply clean water and collect wash-water. This allows washing to continue whilst the waste settles out of the water in the first tank. This system overcomes the problem of the system is described in AU2004100677 in that it can operate continuously by switching between tanks. However, a disadvantage of this system is that the three tank arrangement results in the system being relatively large and complex. Furthermore, this system still relies on significant settlement time before the water collected in any particular tank can be re-used, which may be an issue if one of the other tanks is emptied of clean water before settlement is completed.

To assist in separating out the waste held in suspension in the wash-water an additive may be added. The additive may be a "flocculant", as mentioned above, or a "coagulant". Coagulants clump, or coalesce, fine waste particles together into larger particles that are still relatively small (these particles are known as "pin floe"). Flocculants clump the fine waste particles into larger solids than produced by coagulants, and these larger solids settle out. The present invention seeks to overcome at least one of the disadvantages of the prior art.

SUMMARY OF INVENTION

In a first aspect the present invention consists of a washing apparatus for washing trades equipment, the apparatus comprising:

a supply tank containing a wash fluid in a substantially clean state;

a supply pump for supplying the wash fluid from the supply tank to at least one nozzle for directing the wash fluid at the equipment; at least one receptacle for collecting the wash fluid in a contaminated state, the wash fluid being contaminated with waste washed from the equipment;

a collection tank for holding the wash fluid collected by the receptacle;

a return pump for pumping the wash fluid from the collection tank to the supply tank via at least one return filter for filtering the waste from the contaminated wash fluid thereby returning the wash fluid to its clean state;

and a line that the wash fluid flows through;

characterised in that the apparatus further comprises a dosing device for automatically introducing a coagulant into the wash fluid as it flows through the line.

Preferably, the dosing device introduces the coagulant into the wash fluid when the wash fluid is in its substantially clean state. Preferably, the line is a supply line disposed between the supply pump and the nozzle, such that the wash fluid in its clean state flows through the supply line, and the dosing device is in-line with the supply line. Preferably, the dosing device introduces the coagulant into the wash fluid at a rate substantially proportional to the flow rate the wash fluid through the line. Preferably, the dosing device is powered by the wash fluid flowing through it.

Preferably, the washing apparatus further comprising a collection filter for capturing solids in the wash fluid, the collection filter being disposed between the receptacle and the collection tank. Preferably, the collection filter is a weir tray.

Preferably, the return pump is able to operate intermittently, the return pump starting automatically when the collection tank reaches a predetermined upper level, and stopping when the collection tank reaches a predetermined lower level.

Preferably, the at least one return filter comprises at least two return filters connected in parallel. Alternatively, the at least one return filter comprises at least two return filters connected in series. Preferably, the return filter comprises a filtration vessel.

Preferably, the at least one nozzle comprises two nozzles, and the at least one receptacle comprises two receptacles. Preferably, the nozzle is a trigger nozzle, and the supply pump starts automatically when the trigger nozzle is activated. Preferably, the wash fluid substantially consists of water.

In an alternative embodiment, the dosing device introduces the coagulant into the wash fluid when the wash fluid is in its contaminated state, and preferably, the dosing device is disposed between the collection tank and the return pump.

In a second aspect the present invention consists of a method of washing trades equipment by means of the wash apparatus of the first aspect of the invention, the method comprising directing the wash fluid at the equipment.

In a third aspect the present invention consists of a method of washing trades equipment, the method comprising directing a wash fluid in a substantially clean state, supplied from a supply tank by a supply pump, through a nozzle, at the equipment, collecting the wash fluid in a contaminated state with a receptacle, after the wash fluid has been contaminated with waste washed from the equipment, into a collection tank, and pumping the wash fluid from the collection tank to the supply tank via a return filter to filter the waste from the contaminated wash fluid thereby returning the wash fluid to its clean state, characterised in that the method further comprises using a dosing device to automatically introduce a coagulant into the wash fluid at a rate substantially proportional to the flow rate of the wash fluid through a line.

Preferably, the dosing device introduces coagulant to the wash fluid when the wash fluid is in its substantially clean state. Preferably, the line is a supply line disposed between the supply pump and the nozzle, and the dosing device is in-line with the supply line. Preferably, the wash fluid flows through the dosing device and the dosing device is powered by the wash fluid flowing through it.

In a fourth aspect the present invention consists of a washing apparatus for washing trades equipment using recycled washing fluid, which in use may be treated from wash-water in a contaminated stated to substantially clean water, said apparatus comprising:

at least one washing receptacle for holding or supporting trades equipment to be washed; at least a first reservoir in which said substantially clean water is stored; a first pump for delivery of substantially clean water from said first reservoir to at least one delivery nozzle for directing said substantially clean water at said trades equipment;

a second reservoir in fluid communication with said receptacle so that wash-water in said receptacle will be collected in said second reservoir, a second pump for delivery of said wash- water from said second reservoir to said first reservoir via at least one return filter, said wash- water having contaminants removed therefrom as it passes through said return filter so that it is recycled into said substantially clean water as it leaves said return filter and is delivered to said first reservoir;

characterised in that a dosing device is disposed between said first pump and said delivery nozzle for dosing coagulant to said substantially clean water prior to it being delivered to said nozzle.

Preferably, said dosing device is fitted in line with a supply line fluidally connecting said first pump to said delivery nozzle, said dosing device being operably driven by the flow of said substantially clean water through said supply line. Preferably, said dosing device is able to automatically introduce said coagulant into said substantially clean water at a rate substantially proportional to the flow rate of said substantially clean water through said supply line.

Preferably, said substantially clean water flows through said dosing device. Preferably, said washing apparatus further comprising a collection filter for capturing solids in said wash- water, said collection filter being disposed between said receptacle and said second reservoir. Preferably, said collection filter is a weir tray.

Preferably, said second pump is able to operate intermittently, said second pump starting automatically when said second reservoir reaches a predetermined upper level, and stopping when said second reservoir reaches a predetermined lower level.

Preferably, said at least one return filter comprises at least two return filters connected in parallel. Alternatively, said at least one return filter comprises at least two return filters connected in series. Preferably, said return filter comprises a filtration vessel. Preferably, said at least one nozzle comprises two nozzles, and said at least one receptacle comprises two receptacles. Preferably, said nozzle is a trigger nozzle, and said first pump starts automatically when said trigger nozzle is activated.

In a fifth aspect the present invention consists of a method of washing trades equipment using recycled washing fluid, which in use may be treated from wash-water in a contaminated stated to substantially clean water, said method comprising:

delivering substantially clean water from a first reservoir to a delivery nozzle using a first pump;

directing said substantially clean water from said nozzle to at least one washing receptacle in which said trades equipment is being supported and/or held;

collecting wash-water from said receptacle in a second reservoir;

delivering said wash-water from said second reservoir to said first reservoir via at least one return filter, said wash-water having contaminants removed therefrom as it passes through said filter so that it is recycled into said substantially clean water as it leaves said filter and is delivered to said first reservoir;

characterised in that coagulant is continually added to said substantially clean water prior to it being delivered to said nozzle from said first pump.

Preferably, said coagulant is added to said substantially clean water by as it flows through a dosing device, said dosing device being powered by said substantially clean water by it flowing through it.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is a perspective view of a washing apparatus in accordance with the present invention. Fig. 2 is a rear view of the washing apparatus shown in Fig. 1. Fig. 3 is an exploded view of a washing tray of the washing apparatus shown in Fig. 1. Fig. 4 is a schematic diagram of the washing apparatus shown in Fig. 1. BEST MODE OF CARRYING OUT THE INVENTION

Figs. 1 to 4 show a preferred embodiment of a washing apparatus 1 in accordance with the present invention. Washing apparatus 1 a method of washing trades equipment in accordance with the present invention. Washing apparatus 1 is particularly suited to washing or cleaning painting equipment, such as paint brushes and rollers, but it may also be used for washing other trades equipment.

Washing apparatus 1 comprises an enclosure 2 mounted on a base 3. Base 3 has openings 5 in its sides to enable a forklift truck to lift and move washing apparatus 1. Enclosure 2 supports two washing receptacles, namely two removable wash trays 4. Wash trays 4 are at a height convenient for a person to wash equipment whilst standing. Equipment to be washed is supported by, or held above, wash trays 4 during washing. The two wash trays 4 of this embodiment enable two people to wash equipment at the same time.

A first reservoir, namely supply tank 7, sits on base 3, within the lower half of enclosure 2. Supply tank 7 holds clean wash fluid 8. In this specification, "Clean wash fluid" means that the wash fluid is in a "clean state". Clean wash fluid 8 is typically substantially clean water or water recycled through washing apparatus 1 in a manner that will be described. In this specification, "substantially clean water" means mains tap water or chemically treated (recycled) water. At the start of the operation of washing apparatus 1 , supply tank 7 is filled with clean wash fluid 8, which is usually substantially clean water, from an external source.

A first pump, namely supply pump 9, delivers clean wash fluid 8 on demand through a supply line 10 to two trigger operated delivery nozzles 1 1. Each trigger nozzle 1 1 is connected to supply line 10 by a flexible hose 12. Each nozzle 1 1 directs a stream of clean washing fluid 8 at the equipment being washed. Nozzles 1 1 are tapered, low flow nozzles with blade tips that produce a fan like stream of wash fluid 8 that is efficient for washing. Typically, the flow rate through a nozzle 1 1 may be about 4 litres per minute. Supply pump 9 starts automatically when the trigger of one of nozzles 1 1 is activated by a user.

A dosing device 14 is positioned in-line with supply line 10, between supply pump 9 and nozzles 1 1 , to introduce (dose) a coagulant 15 into clean wash fluid 8 as it flows through supply line 10, prior to it being delivered to nozzles 1 1. Dosing device 14 automatically introduces a coagulant 15 into clean wash fluid 8 as it flows through dosing device 14, thereby mixing coagulant 15 with clean wash fluid 8. A suitable dosing device 14 is a Dosatron brand device that is powered, or operably driven, by the flow of clean wash fluid 8 through it. The Dosatron device having a model number DI 1500 is particularly well suited to this application. Dosing device 14 draws coagulant 15 from a coagulant reservoir 16 through a tube 17. Dosing device 14 introduces coagulant 15 into clean wash fluid 8 at a rate substantially proportional to the flow rate of clean wash fluid 8 through dosing device 14. Dosing device 14 is adjustable to vary the rate that it introduces coagulant 15.

Once clean wash fluid 8 passes over equipment being washed it becomes contaminated wash fluid 18 that is contaminated with waste washed off the equipment. "Contaminated wash fluid" means that the wash fluid is in a "contaminated state". The "Contaminated wash fluid" is also known as "wash-water" in water based cleaning systems. After it passes over the equipment being washed, the contaminated wash fluid 18 is collected by wash trays 4. Each wash tray 4 includes a removable perforated panel 19 that the contaminated wash fluid 18 passes through. Perforated panels 19 can be used to support equipment being washed and they capture larger solid waste. The contaminated wash fluid 18 collected by wash trays 4 passes through a collection filter to capture solids or heavier waste in the contaminated wash fluid 18. In this embodiment, the collection filter comprises a set of three weir trays 20 within each wash tray 4. Contaminated wash fluid 18 flows into the open top of weir trays 20, and the heavier solids settle to the bottom of weir trays 20 whilst the remaining contaminated wash fluid 18 flows over the edges of weir trays 20. Weir trays 20 are removable to clean out waste collected by them.

After contaminated wash fluid 18, collected by wash trays 4, flows over the edges of weir trays 20, it then flows into a second reservoir, namely collection tank 22. Collection tank 22 is in fluid communication with wash trays 4 by means of contaminated wash fluid 18 flowing from wash trays 4 to collection tank 22 via weir trays 20. Collection tank 22 sits within enclosure 2 above supply tank 7. Collection tank 22 includes an upper level switch 23 that triggers when the fluid level in collection tank 22 reaches a predetermined upper level, and a lower level switch 24 that triggers when the fluid level in collection tank 22 drops to a predetermined lower level.

A second pump, namely return pump 25, is connected to an outlet 28 near the bottom of collection tank 22. Contaminated wash fluid 18 is held in collection tank 22 until it reaches the upper level and triggers upper level switch 23, which signals return pump 25 to automatically start pumping contaminated wash fluid 18 from collection tank 22. Pumping continues until the level in collection tank 22 drops to the lower level and triggers lower level switch 24, which signals return pump 25 to stop.

Return pump 25 pumps contaminated wash fluid 18 through a return filter system to deliver it back to supply tank 7. The return filter system comprises four return filters 26 connected in parallel by a manifold 27. Each return filter 26 is a pressure vessel type filtration unit containing a filtration media. A suitable filter for return filters 26 is the "Flowline II" stainless steel bag filter made by Eaton. Returns filters 26 substantially remove the waste

(contaminants) from the contaminated wash fluid 18 thereby recycling the wash fluid back into clean wash fluid 8, which means that the wash fluid is returned to a "clean state".

By the time the contaminated wash fluid 18 reaches return filters 26, the coagulant 15 introduced into the wash fluid when it was in its clean state 8 has sufficiently coalesced the fine waste particles into clumps (pin floe) that can be captured by filters 26. This overcomes a problem of prior art systems that need to wait, sometimes for many hours, for waste to settle out of contaminated wash fluid before the wash fluid can be re-used. Apparatus 1 re-cycles the wash fluid continuously without the complication or space requirements of prior art continuous systems that use multiple tanks.

The method of introducing coagulant 15 into the wash fluid in its clean state 8, before it is directed onto the equipment to be washed, has been found to be particularly effective at efficiently and quickly coagulating the waste in the contaminated wash fluid 18.

A further advantage of introducing the coagulant 15 into the clean wash fluid 8 before it reaches nozzles 1 1 is that the coagulant 15 is well mixed with the wash fluid 8. Also, the dosing device 14 operates more reliably, and is easier to service, with clean wash fluid 8 flowing through it.

After passing through filters 26, the now clean wash fluid 8 is returned to supply tank 7 via another manifold 29 and a return line 30. In this manner, the wash fluid is recycled through the system.

Pressure switches 32 and 33 at the inlet and outlet respectively of filters 26, and a throttle valve 34 in return line 30 are used to check whether filters 26 are blocked and need to be emptied or have the filtration media changed. Throttle valve 34 creates a back pressure in return line 30 that varies with the flow through return line 30. The pressure drop across filters 26 increases as they become blocked. A light tower 36 on top of enclosure 2 indicates the state of filters 26. When light tower 36 is green it indicates that filters 26 are not blocked, and washing apparatus 1 may be used. When light tower 36 is orange, this indicates that filters 26 are becoming blocked and will soon need to be changed. When light tower 36 is red, filters 26 are blocked and the system stops.

Because return pump 25 operates intermittently by means of level switches 23 and 24, it is possible to continue to wash equipment whilst changing or cleaning filters 26, with return pump 25 stopped, providing the level in collection tank 22 does not exceed the upper level.

The pumps 9 and 25, light tower 36, and other actuators of washing apparatus 1 are controlled by a programmable logic controller (not shown) using switches 23, 24, 32, and 33 as inputs. In other not shown embodiments of the invention, coagulant may be introduced into the wash fluid when it is in a contaminated state (instead of when it is in a clean state). Means other than a Dosatron brand dosing device may be used to introduce coagulant into the contaminated wash fluid. For example, this may be achieved by a positive displacement pump, such as a peristaltic pump, positioned to introduce coagulant into a line between the outlet of the collection tank and the inlet of the return pump, as the contaminated wash fluid flows through this line. Baffles in the line may be provided to assist the coagulant to mix with the wash fluid. The positive displacement pump may be set to deliver coagulant at a constant flow rate proportional to the flow rate of the return pump. Such a system, or other not shown dosing means, may also be used to introduce coagulant into the wash fluid in its clean state.

In other not shown embodiments of the inventions, the washing apparatus may have other than two wash trays 4 and two nozzles 1 1. For example, a simpler system may have only one wash tray 4 and one nozzle 1 1.

In other not shown embodiments of the inventions, the return filter system may comprise other than four filters 26, or the filters may be arranged in series instead of parallel. For example, the filters may be arranged in series with progressively coarsening filters, or only one or two filters may be used in simpler systems. Also filters other than of a pressure vessel type may be used.

The terms "comprising" and "including" (and their grammatical variations) as used herein are used in an inclusive sense and not in the exclusive sense of "consisting only of.

Claims

1. A washing apparatus for washing trades equipment, the apparatus comprising:

s a supply tank containing a wash fluid in a substantially clean state;

a supply pump for supplying the wash fluid from the supply tank to at least one nozzle for directing the wash fluid at the equipment;

at least one receptacle for collecting the wash fluid in a contaminated state, the wash fluid being contaminated with waste washed from the equipment;

0 a collection tank for holding the wash fluid collected by the receptacle;

and a line that the wash fluid flows through;

s characterised in that the apparatus further comprises a dosing device for automatically introducing a coagulant into the wash fluid as it flows through the line.

2. A washing apparatus as claimed in claim 1, wherein the dosing device introduces the coagulant into the wash fluid when the wash fluid is in its substantially clean state.

0

3. A washing apparatus as claimed in claim 1 , wherein the line is a supply line disposed between the supply pump and the nozzle, such that the wash fluid in its clean state flows through the supply line, and the dosing device is in-line with the supply line. 5

4. A washing apparatus as claimed in claim 1 , wherein the dosing device introduces the coagulant into the wash fluid at a rate substantially proportional to the flow rate the wash fluid through the line.

5. A washing apparatus as claimed in claim 4, wherein the dosing device is powered by the0 wash fluid flowing through it.

6. A washing apparatus as claimed in claim 1 , further comprising a collection filter for capturing solids in the wash fluid, the collection filter being disposed between the receptacle and the collection tank.

7. A washing apparatus as claimed in claim 6, wherein the collection filter is a weir tray.

8. A washing apparatus as claimed in claim 1 , wherein the return pump is able to operate intermittently, the return pump starting automatically when the collection tank reaches a predetermined upper level, and stopping when the collection tank reaches a predetermined lower level.

9. A washing apparatus as claimed in claim 1 , wherein the at least one return filter comprises at least two return filters connected in parallel.

10. A washing apparatus as claimed in claim 1 , wherein the at least one return filter comprises at least two return filters connected in series.

1 1. A washing apparatus as claimed in claim 1 , wherein the return filter comprises a filtration vessel.

12. A washing apparatus as claimed in claim 1 , wherein the at least one nozzle comprises two nozzles, and the at least one receptacle comprises two receptacles.

13. A washing apparatus as claimed in claim 1 , wherein the nozzle is a trigger nozzle, and the supply pump starts automatically when the trigger nozzle is activated.

14. A washing apparatus as claimed in claim 1 , wherein the wash fluid substantially consists of water.

15. A washing apparatus as claimed in claim 1 , wherein the dosing device introduces the coagulant into the wash fluid when the wash fluid is in its contaminated state.

16. A washing apparatus as claimed in claim 15, wherein the dosing device is disposed between the collection tank and the return pump.

17. A method of washing trades equipment by means of a wash apparatus as claimed in claim 1 , the method comprising directing the wash fluid at the equipment.

18. A method of washing trades equipment, the method comprising directing a wash fluid in a substantially clean state, supplied from a supply tank by a supply pump, through a nozzle, at the equipment, collecting the wash fluid in a contaminated state with a receptacle, after the wash fluid has been contaminated with waste washed from the equipment, into a collection tank, and pumping the wash fluid from the collection tank to the supply tank via a return filter to filter the waste from the contaminated wash fluid thereby returning the wash fluid to its clean state, characterised in that the method further comprises using a dosing device to automatically introduce a coagulant into the wash fluid at a rate substantially proportional to the flow rate of the wash fluid through a line.

19. A method of washing trades equipment as claimed in claim 18, wherein the dosing device introduces coagulant to the wash fluid when the wash fluid is in its substantially clean state.

20. A method of washing trades equipment as claimed in claim 18, wherein the line is a supply line disposed between the supply pump and the nozzle, and the dosing device is in-line with the supply line.

21. A method of washing trades equipment as claimed in claim 18, wherein the wash fluid flows through the dosing device and the dosing device is powered by the wash fluid flowing through it.

22. A washing apparatus for washing trades equipment using recycled washing fluid, which in use may be treated from wash-water in a contaminated stated to substantially clean water, said apparatus comprising:

a second reservoir in fluid communication with said receptacle so that wash-water in said receptacle will be collected in said second reservoir, a second pump for delivery of said 5 wash-water from said second reservoir to said first reservoir via at least one return filter, said wash- water having contaminants removed therefrom as it passes through said return filter so that it is recycled into said substantially clean water as it leaves said return filter and is delivered to said first reservoir;

characterised in that a dosing device is disposed between said first pump and said delivery 10 nozzle for dosing coagulant to said substantially clean water prior to it being delivered to said nozzle.

23. A washing apparatus as claimed in claim 1 , wherein said dosing device is fitted in line with a supply line fluidally connecting said first pump to said delivery nozzle, said dosing

15 device being operably driven by the flow of said substantially clean water through said supply line.

24. A washing apparatus as claimed in claim 23, wherein said dosing device is able to

automatically introduce said coagulant into said substantially clean water at a rate

20 substantially proportional to the flow rate of said substantially clean water through said supply line.

25. A washing apparatus as claimed in claim 23, wherein said substantially clean water flows through said dosing device.

25

26. A washing apparatus as claimed in claim 22, further comprising a collection filter for capturing solids in said wash-water, said collection filter being disposed between said receptacle and said second reservoir.

30 27. A washing apparatus claimed in claim 25, wherein said collection filter is a weir tray.

28. A washing apparatus claimed in claim 22, wherein said second pump is able to operate intermittently, said second pump starting automatically when said second reservoir reaches a predetermined upper level, and stopping when said second reservoir reaches a predetermined lower level.

29. A washing apparatus as claimed in claim 22, wherein said at least one return filter 5 comprises at least two return filters connected in parallel.

30. A washing apparatus as claimed in claim 22, wherein said at least one return filter

comprises at least two return filters connected in series.

10 31. A washing apparatus claimed in claim 22, wherein said return filter comprises a filtration vessel.

32. A washing apparatus as claimed in claim 22, wherein said at least one nozzle comprises two nozzles, and said at least one receptacle comprises two receptacles.

15

33. A washing apparatus claimed in claim 22, wherein said nozzle is a trigger nozzle, and said first pump starts automatically when said trigger nozzle is activated.

34. A method of washing trades equipment using recycled washing fluid, which in use may be 20 treated from wash-water in a contaminated stated to substantially clean water, said method comprising:

directing said substantially clean water from said nozzle to at least one washing receptacle 25 in which said trades equipment is being supported and/or held;

collecting wash-water from said receptacle in a second reservoir;

delivering said wash-water from said second reservoir to said first reservoir via at least one return filter, said wash-water having contaminants removed therefrom as it passes through said filter so that it is recycled into said substantially clean water as it leaves said filter and 30 is delivered to said first reservoir;

35. A method of washing trades equipment claimed in claim 34, wherein said coagulant is added to said substantially clean water by as it flows through a dosing device, said dosing device being powered by said substantially clean water by it flowing through it.