WO1996033817A1

WO1996033817A1 - Soap foam generator

Info

Publication number: WO1996033817A1
Application number: PCT/CA1996/000267
Authority: WO
Inventors: Michael E. S. Lawrence; James Andrew Smith
Original assignee: Lawrence Michael E S; James Andrew Smith
Priority date: 1995-04-25
Filing date: 1996-04-26
Publication date: 1996-10-31
Also published as: CA2148192A1; AU5394496A

Abstract

A device for mixing air, soap and water and delivering the resultant foamy soap mixture to a spray wand (42) comprises a mixing chamber (4) able to withstand the high pressures existent when a pressure washer system is in the wash or rinse mode; a high-pressure inlet line (9); an air-supply line with a pressure regulator (16) and a check valve (18); a soap-supply (26) line with a regulator valve (24); and a discharge line (34) with a high pressure gauge (40), all of which are housed in a container. When a soap-applicator nozzle is attached to the end of the spray wand, the resultant system pressure drop to near zero causes the pressure washer soap syphon to introduce soap into the pressure washer discharge line. The amount of soap thus syphoned is regulated by a valve. The soap/water mixture then enters the mixing chamber, where air is forced into the mixture. The air enters the mixing chamber through an air-supply line and a check valve. The air pressure in the air-supply line forces open the check valve when the system pressure is near zero. The action of introducing air into the soap/water mixture creates a thick foamy mixture which discharges from the mixing chamber to the supply hose to the wash wand where it is applied to the surface to be cleaned. When the soap-applicator nozzle is exchanged for a high-pressure wash nozzle, the resultant high pressure causes the pressure washer soap syphon to cease operating, and the check valve in the air supply line closes. Clear water under high pressure now enters and exits the mixing chamber, travels to the spray wand and is discharged through the high-pressure nozzle in order to rinse the object surface clean.

Description

Soap Foam Generator

A soap foam generator is a device that mixes soap, water and air to create a foamy mixture that is applied to a surface to be cleaned. The surface is then rinsed clean with a pressure washer. It is desirable to create a thick soap foam so that the soap clings to the surface to be cleaned, prolonging the dwell time on the surface. The longer the dwell time, the more effective the cleaning action. With more effective cleaning action, milder, more environmentally safe soaps can be utilized.

There are several existing methods of creating a soap foam. One such method consists of a soap/water mixing device installed at the pressure washer pump. The resultant soap/water mixture is then applied through a normal high-pressure nozzle. The foaming effect achieved is minimal.

Another such device consists of a soap-foaming nozzle attached to the end of a pressure washer spray wand. A foaming effect is generated by the turbulence in the soap/water mixture as it exits the nozzle under high pressure. The foaming effect is minimal and is further reduced by the fact that the water/soap mixture is applied under high pressure. During application under high pressure, the water/soap mixture tends to be blasted off of the surface to be cleaned, even as it is being applied. Soap consumption is high and therefore the method is uneconomical.

The most effective foaming device currently in use consists of a spray wand which applies an air/soap/water mixture under the pressure of the domestic water supply. The disadvantage of this system is that two separate mechanical systems are required: the apparatus for supplying and mixing the air, soap and water (with its attendant supply hoses and applicating wands); plus the pressure washer system for rinsing (with its attendant pressure supply hose and wand).

What is needed is a compact air/soap/water -mixing device that can withstand the high pressure created by the pressure washer, enabling it to be integrated into the pressure washer system so that only one hose-plus-wand assembly is required and the only control function required of the operator is to open and close a trigger shutoff gun on the spray

SUBSTITUTE SHEET wand and to exchange a soap-applicator nozzle with a high-pressure rinse nozzle by means of a quick coupler, or some other means, on the spray wand.

The invention consists of a box containing an air/soap/water mixing chamber with an air-pressure regulator, and a soap-regulating valve. The box could be mounted on a pressure washer system, or be independently mounted (for example, on a wall). The mixing chamber consists of separate water- and air-inlet fittings threaded into one end, and a water-outlet fitting threaded into the other end. A coiled tube with many small perforations is fitted inside the mixing chamber with one end of the tube attached to the air-inlet fitting, and the other end closed. The water-inlet fitting is attached to the discharge line of a pressure washer pump by means of high-pressure fittings. The air-inlet fitting is connected to a high pressure air line, to which an air regulator is fitted. A check valve is installed in the air line between the mixing chamber and the air regulator. The water-outlet fitting of the mixing chamber is connected to a high-pressure hose and wash wand.

When the pressure washer is operating in the rinse mode, i.e. under high pressure with the high-pressure nozzle attached to the wash wand and the trigger gun open, high-pressue water from the pressure washer pump enters the mixing chamber and exits through the outlet fitting to the wash wand via the high-pressure hose. The high-pressure condition in the mixing chamber forces both the air-line check valve and the soap-siphon check valve closed. When the high-pressure rinse nozzle is exchanged for a low-pressure soap nozzle, the system pressure drops to near zero, and the air-line and soap-siphon check valves open, admitting air and soap into the mixing chamber, where they mix with the low-pressure water from the pressure washer pump. The soap siphon is fitted into the discharge line of the pressure washer, downstream of the bypass/unloader, and operates with normal pump discharge water volume, at low pressure. A thick, foamy mixture is created, which exits the mixing chamber through the outlet fitting to the high-pressure hose through the trigger shutoff gun and through the wand where it is sprayed out through the soap nozzle onto the surface to be cleaned.

SUBSTITUTE SHEET These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where:

Figure 1 is a schematic illustrating the way in which a soap foam generator embodying one aspect of the invention connects to a pressure washer, air supply, soap supply, high-pressure wash hose, shutoff gun, wand and nozzle. Figure 2 is a schematic view of the soap foam generator of Figure 1 ; and Figure 3 is a sectional side view of the mixing chamber of the soap foam generator of Figure 1.

The invention, as exemplified by a preferred embodiment, will now be described. With reference to Figures 1, 2, and 3. a control box and panel is generally illustrated at 2. The control box and panel 2 contains a sealed mixing chamber 4 housing a perforated tube sealed at one end 6. The housing of the mixing chamber 4 is threaded for a water-inlet fitting 8 and an air-inlet fitting 10 at one end and a water-outlet fitting 12 at the other end. The air-supply line 14 is attached to the air-inlet fitting 10 via an air regulator 16. a check valve 18, pressure gauge 20. and with a bulkhead penetrator 22. The control box, shown in Figures 1 and 2, contains a soap regulator 24 connecting a supply line 26 to a discharge line 28, each respectively passing through bulkhead penetrator fittings 30. 32. The discharge line 34 of the mixing chamber 4 is connected to a bulkhead penetrator 36. A high pressure gauge 40 is connected to the mixing chamber discharge line 34. A wash wand 42 with trigger shutoff gun 44 is connected to the high-pressure hose 38 and either a high-pressure wash nozzle 45 or a low-pressure soap applicator nozzle 48 is attached to the wand 42.

With the pressure washer 50. running with a low-pressure soap-applicator nozzle 48 attached to the wash wand 42 and with the trigger shutoff gun 44 open, a condition of near-zero pressure exists in the entire system. The pressure washer soap siphon 52 draws soap into the pressure washer discharge line through the regulator valve 24 and the soap/water mixture enters the mixing chamber 4 via the bulkhead penetrator fitting 54, inlet-water line 9 and threaded fitting 8. Simultaneously, compressed air passes through the air regulator 16 that controls the air pressure, and through the check valve 18 to

SUBSTITUTE SHEET perforated tube 6. where it then enters the mixing chamber 4. The air exits the tube 6 through tiny holes and mixes with the water/soap mixture. This mixing action within the mixing chamber 4 creates a thick foamy mixture, which is discharged to the wash wand 42 through the soap-applicator nozzle 48 onto the surface to be cleaned.

When the low-pressure soap-applicator nozzle 48 is exchanged for a high-pressure wash nozzle 46, the pressure washer system pressure returns to its normal high-pressure condition, the soap siphon 52 ceases to draw soap, the air-supply check valve 18 closes, and clear water is forced through the system to the wash wand 42 under high pressure, and the object surface is rinsed clean. The flow of water from the pressure washer through the system is controlled by the trigger shutoff gun 44 and a bypass/unloader on the pressure washer.

It is contemplated that the soap foam generator can be used on both electrically-driven pressure washers and pressure washers driven by internal combustion engines.

Although only a single embodiment of the present invention has been described and illustrated, the present invention is not limited to the features of this embodiment, but includes all variations and modifications within the scope of the claims.

It is further contemplated that the soap foam generator can be used in conjunction with a pressure washer that employs a soap injection system instead of a soap siphon system.

It is still further contemplated that the operation of the soap foam generator would be enhanced if a governor control was employed on a pressure washer driven by an internal combustion engine. A governor control would reduce engine speed, thus reducing the volume of water through the system, enabling the operator to apply the foam at a more leisurely pace, thus reducing the potential for wasting soap.

It is still further contemplated that the components comprising the soap foam generator could be assembled outside a box or container and be independently mounted to a pressure washer system, so long as they are interconnected as described.

SUBSTITUTE SHEET

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS: 1. In a pressure washer having a first output port for discharging a cleaning mixture, an apparatus for foaming the cleaning mixture, comprising: (a) means for receiving the cleaning mixture from the first output port, said receiving means being robust enough to withstand the cleaning mixture pressure, (b) means for introducing a gas into said receiving means, said gas introducing means being arranged to pass the gas through the cleaning mixture so as to foam the cleaning mixture, (c) means for preventing the cleaning mixture from freely back-flowing into said gas introducing means, and (d) a second output port for discharging the foamed cleaning mixture.

2. An apparatus as in claim 1 , wherein said receiving means includes a chamber.

3. An apparatus as in claim 2, wherein said gas introducing means is a perforated pipe, said pipe being substantially located within said chamber and having a first and second end, the first end being adapted to receive the gas from an external supply and the second end being substantially closed to oppose passage of the gas.

4. An apparatus as in claim 3, wherein said perforated pipe coils through said chamber so as to distribute the gas there through.

5. An apparatus as in claim 4, wherein said back-flow preventing means includes a check valve connected between the first end of said perforated pipe and the external gas supply.

6. An apparatus as in claim 5 wherein the gas introducing means includes means for regulating the pressure of the gas being introduced.

7. An apparatus for use with a pressure washer having a first output port for discharging a cleaning mixture, the apparatus comprising: (a) means for receiving the cleaning mixture from the first output port, said receiving means being robust enough to withstand the cleaning mixture pressure,

SUBSTITUTE SHEET (b) means for introducing a gas into said receiving means, said gas introducing means being arranged to pass the gas through the cleaning mixture so as to foam the cleaning mixture,

(c) means for preventing the cleaning mixture from freely back-flowing into said gas introducing means, and

(d) a second output port for discharging the foamed cleaning mixture.

8. An apparatus as in claim 7, wherein said receiving means includes a chamber.

9. An apparatus as in claim 8, wherein said gas introducing means is a perforated pipe, said pipe being substantially located within said chamber and having a first and second end, the first end being adapted to receive the gas from an external supply and the second end being substantially closed to oppose passage of the gas.

10. An apparatus as in claim 9. wherein said perforated pipe coils through said chamber so as to distribute the gas there through.

1 1. An apparatus as in claim 10, wherein said back- flow preventing means includes a check valve connected between the first end of said perforated pipe and the external gas supply.

12. An apparatus as in claim 1 1, wherein the gas introducing means includes means for regulating the pressure of the gas being introduced.

13. An apparatus for foaming a cleaning mixture, comprising: (a) means for receiving the cleaning mixture, said receiving means being robust enough to withstand die cleaning mixture pressure, (b) means for introducing a gas into said receiving means, said gas introducing means being arranged to pass the gas through the cleaning mixture so as to foam the cleaning mixture, (c) means for preventing the cleaning mixture from freely back-flowing into said gas introducing means, and (d) an output port for discharging d e foamed cleaning mixture.

14. An apparatus as in claim 13, wherein said receiving means includes a chamber.

15. An apparatus as in claim 14, wherein said gas introducing means is a perforated pipe, said pipe being substantially located within said chamber and having a first and second end. the first end being adapted to receive the gas from an external supply and the second end being substantially closed to oppose passage of the gas.

SUBSTITUTE SHEET

16. An apparatus as in claim 15, wherein said perforated pipe coils through said chamber so as to distribute the gas there through.

17. An apparatus as in claim 16, wherein said back-flow preventing means includes a check valve connected between the first end of said perforated pipe and the external gas supply.

18. An apparatus as in claim 17, wherein the gas introducing means includes means for regulating the pressure of the gas being introduced.

19. In combination:

(a) A pressure washer comprising: (i) means for receiving water and a cleaning agent,

(ii) a pump connected to the water and cleaning agent receiving means for mixing the water and the cleaning agent and for pressurizing the resultant cleaning mixture, (iii)a motor connected to the pump for driving the pump, (iv)a governor control connected to the motor for slowing the motor to reduce the pressure of the cleaning mixture in preparation for foaming, and (v) a first output port for discharging the cleaning mixture, and

(b) an apparatus for foaming a cleaning mixture, comprising:

(i) means for receiving the cleaning mixture from the first output port, said mixture receiving means being robust enough to withstand the cleaning mixture pressure, (ii) means for introducing a gas into said mixture receiving means, said gas introducing means being arranged to pass the gas through the cleaning mixture so as to foam the cleaning mixture, (iii)means for preventing the cleaning mixture from freely back-flowing into said gas introducing means, and (iv)a second output port for discharging the foamed cleaning mixture.

20. An apparatus as in claim 19, wherein said receiving means includes a chamber.

21. An apparatus as in claim 20, wherein said gas introducing means is a perforated pipe, said pipe being substantially located within said chamber and having a first and second end, the first end being adapted to receive the gas from an external supply and the second end being substantially closed to oppose passage of the gas.

SUBSTITUTE SHEET

22. An apparatus as in claim 21, wherein said perforated pipe coils through said chamber so as to distribute the gas there through.

23. An apparatus as in claim 22, wherein said back-flow preventing means includes a check valve connected between the first end of said perforated pipe and the external gas supply.

24. An apparatus as in claim 23, wherein the gas introducing means includes means for regulating the pressure of the gas being introduced.

SUBSTITUTE SHEET