Soap Proportioning Means For A Variable Capacity Wash Pump

Abstract

Proportioning apparatus comprising a water tank and a soap tank connected by piping with the inlet of a high pressure, variable capacity pump. The ratio of soap to water is maintained constant for any given washing requirement by flow restriction in the piping leading from each of the tanks to the pump. A constant ratio of soap to water is assured by float-operated valves on the tanks to maintain an equal level or hydrostatic head, or a differential in head, depending upon the relative specific gravities of the liquid soap and water. If the specific gravities are equal, or the head of the liquids is adjusted to compensate for the difference in specific gravity, there will be no interchange of the water and soap from one tank to the other. This arrangement also eliminates the need for check valves in the system. Equal or unequal levels may be maintained in the tanks, regardless of the difference in specific gravities, and interchange prevented by check valves. Flow from the two tanks is induced by suction created by the pump. The degree of suction and volume of water withdrawn from the water tank is controlled by prescribed flow restriction, for example, by a fixed orifice or a variable throttle valve upstream of the pump. The proportionate volume of liquid soap withdrawn from the soap tank is also controlled by prescribed flow restriction, for example, a fixed orifice or an adjustable throttle valve, located upstream of the pump. Fixed orifices sized to provide the desired ratio of soap to water can be used with the adjustable valves. Proportionate flow can also be effected by using appropriate size piping. The discharge side of the pump is connected with a manifold having branch pipes for delivering cleaning solution to high pressure cleaning jet nozzles. The valve in the soap supply line can be closed to cut off the soap flow during a rinsing operation.

Description

1. Field of the Invention

The present invention relates to proportioning apparatus for simultaneously providing a high pressure jet of water, with or without soap, to a plurality of car wash stations, or a plurality of jets to a single large wash station. The systems are designed to maintain the proportion, or ratio, of soap to water constant, regardless of fluctuations in demand at the several stations or the single station.

2. Description of the Prior Art

Apparatus has been heretofore devised for mixing two different liquids in prescribed proportions, but such devices are usually quite complicated and require very precise means, including proportioning pumps, flow meters or the like, for metering the two liquids in the desired ratio. Difficulties have arisen in connection with such apparatus when the two metered liquids are being supplied under pressure to a distribution point where the demand for the mixed liquids is frequently interrupted, fluctuates continually, and/or varies from time to time. None of such devices is capable of adjusting their rate of operation to that of the changes in demand and hence are impractical for purposes of the present invention.

SUMMARY OF THE INVENTION

In contrast with the foregoing, the present invention provides a system that is capable of proportioning different liquids and delivering a large volume of the resulting solution simultaneously to a plurality of points, each subject to variable demand, and of automatically adapting itself to such changes in demand without any change in the ratio of the liquids in the solution being delivered. This is accomplished by employing a variable capacity centrifugal pump, or a positive displacement pump with a by-pass, and means that limits the rate of flow of the respective liquids to the suction or inlet side of the pump. Such pumps are arranged in the system so that they can "slip" or by-pass liquid in accordance with changes in the degree of demand.

More specifically, the present invention relates to apparatus for proportioning soap and water to form a cleaning solution for delivery by a variable capacity pump to one or more high pressure nozzles for a car wash or other installations.

In one operative embodiment of the invention, a centrifugal pump, or positive displacement pump, can be used that is operated at a speed to pump 40 gallons of liquid per minute at a pressure of 575 pounds per square inch. With such capacity, liquid can be simultaneously delivered by the pump, for example, to each of four car wash stations for use at a rate of up to 10 gpm at each station. The demand can vary from zero, when all stations are shut down, up to 40 gpm, depending upon the number of wash stations that are in operation at a given time.

The present proportioning apparatus is extremely simple from a structural standpoint and comprises a first tank containing water and a second tank containing liquid soap. The water and soap are supplied through piping to the inlet of the pump. A constant ratio of water to soap is maintained by placing a restriction in the water supply pipe and in the soap supply conduit, respectively, on the suction side of the pump. such restrictions control the suction on the inlet side of the pump and may be in the form of fixed or variable orifices, or may be provided by piping of a prescribed inside diameter, or by inserting a short section of pipe in a pipe line of larger diameter than said section. An adjustable orifice can readily be provided wherever desired by using an adjustable throttle valve.

In a preferred embodiment, an orifice of fixed size is connected in the pipe leading from the water tank to the pump, and an adjustable throttle valve is connected in the conduit leading from the soap tank to the pump. The system can be adjusted to deliver only water for a rinsing operation, simply by closing the throttle valve in the soap supply conduit.

A constant ratio of water to soap can be assured when the specific gravity of both are equal by maintaining the water and soap at approximately the same level in their respective tanks. This is effected by mounting a float-operated control valve on each of the tanks. This creates an equal hydrostatic head in each of the tanks and also avoids the necessity of placing check valves in the system to prevent an interchange of water or soap from one tank to the other. Check valves are necessary when the specific gravities vary and the levels are either equal or unequal.

A manifold is connected with the pump outlet and has a branch pipe leading to one or more cleaning nozzles located in any desired area. A remotely controlled solenoid-operated shut off valve may be connected in the soap conduit to cut off the supply of soap during a rinsing operation.

The principal object of the invention is to provide liquid proportioning apparatus that is capable of continually mixing different liquids in constant predetermined proportions, and of delivering the mixture to one or more points of use, and maintaining the prescribed proportions, regardless of fluctuations in the demand at the point or points of use.

Another object is to provide liquid proportioning apparatus in which the relative proportions of the liquids can be varied as desired.

A more specific object is to provide apparatus for proportioning water and liquid soap to form a soap solution for use in washing automobiles and the like, and which is capable of delivering at all times a washing solution having a uniform soap content.

Another object is to provide liquid proportioning apparatus for mixing soap and water in predetermined proportions to provide a cleaning solution, and which can be adjusted to deliver a relatively weak solution, or water only in lieu of a soap solution.

Another object is to provide proportioning apparatus that is relatively simple in construction, easy to use, and economical to manufacture.

Other objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 diagrammatically illustrates one embodiment of the present liquid soap and water proportioning system associated with a car wash installation comprising four separate wash stalls; and a cleaning nozzle in each stall; and

FIG. 2 diagrammatically illustrates another embodiment wherein four cleaning nozzles are located in a single work area, and a switch is located in said area for operating a remote valve to cut off soap supply and provide a flow of water only to the nozzles.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawing, a first tank 2 contains a body of water 4, and a second tank 6 contains a body of liquid soap 8. Water is supplied to the tank 4 through a pipe 10 connected with a float-operated valve 12 installed on the tank 2. Liquid soap is supplied to the tank 6 through a pipe 14 connected with a similar float-operated valve 16 mounted on the tank 6. The float valves 12 and 16 maintain a predetermined, substantially equal liquid level in the tanks 2 and 6 as indicated by the levels 18 and 20, respectively. By maintaining the two levels 18 and 20 the same, and when the soap and water are of the same specific gravity, equal hydrostatic heads are provided, which prevent interchange or water and soap between the tanks 2 and 6 and eliminate the need for check valves in the piping leading therefrom.

The tank 2 has an outlet 22 to which one end of a first pipe 24 is connected. The other end of the pipe 24 is connected to the inlet 26 of a conventional, variable capacity, high pressure centrifugal pump 28. A fixed orifice 30 is connected in the pipe 24 to limit the rate at which the suction of the pump 28 can withdraw water from the tank 2. A valve 32 may be connected in the pipe 24 between the fixed orifice 30 and the tank outlet 22. The valve 32 serves the purpose of a shut-off valve, and can also serve as a throttling flow restricting valve, when the desired flow of water through the pipe 24 is to be less than that provided by the fixed size orifice 30.

The soap tank 6 has an outlet 34 to which one end of a conduit 36 is connected. The other end of the conduit 36 is connected to the pipe 24 at a point 38, between the orifice 30 and the pump inlet 26. The conduit 28 may have a fixed size orifice 40 mounted therein to restrict the maximum flow of soap that can be drawn from the soap tank 6 by the suction of the pump 28. The relative sizes of the orifices 30 and 40 are designed to provide the desired proportion of soap and water in the soap solution discharged from the pump 28. An adjustable throttling valve 42 is connected in the conduit 36 between the soap tank outlet 34 and the fixed orifice 40. The valve 42 can serve as a shut-off valve, and can also be used as a variable orifice for controlling soap flow when the proportion of soap is to be less than that provided for by the fixed orifice 40. In a system designed for a given water capacity with provision for varying the proportion of soap, the valve 32 and the orifice 40 can both be omitted.

A vacuum gauge 44 is connected to the pipe 24 at a point 46 between the pump inlet 26 and the point of connection 38 of the conduit 36 with the pipe 24.

The pump 28 has an outlet 48 to which one end of a second pipe 50 is connected. The other end of the pipe 50 is connected at 52 to a manifold 54. Branch pipes 56, 58, 60, 62 are connected with the manifold 54 for supplying soap solution to car wash stalls 64, 66, 68 and 70, respectively. The branch pipe 56 has a shut-off valve 72 connected thereto, which controls the flow of soap solution through a hose 74 to a cleaning nozzle 76. A control valve 78 is mounted in the nozzle structure for convenience of the operator in controlling the flow through the nozzle 76. A similar shut-off valve, hose, nozzle and control valve are connected with each of the branch pipes 58, 60 and 62, and are identified by the same reference numerals.

In one operative embodiment of the invention, the centrifugal pump 28 has a capacity of 40 gpm at a pressure of 575 psi. This provides for the simultaneous delivery of up to 10 gpm of liquid at each wash station 64, 66, 68 and 70, which is more than adequate for car wash purposes.

Heretofore, it has been difficult to provide a spray of cleaning solution of uniform soap consistency in a system where the demand varies over a considerable range. This problem is overcome by the present system, since for any given demand, a controlled vacuum is created on the suction side of the pump 28 by the flow restricting orifices 30 and 40. Thus, at a maximum flow of 40 gpm, the vacuum gauge reading would be 8 inches Hg. When the demand on the pump 28 is reduced to 10 gpm, the suction would drop to 0.5 inches Hg, thereby allowing a directly proportionate reduction in the volume of soap that can be drawn from the conduit 26 along with the water drawn from pipe 24.

The use of the pump 28 for delivering a cleaning solution containing soap and water to one or more nozzles of varying operating demand, solves the problem of maintaining a uniform proportion of soap in the cleaning solution, regardless of fluctuations in demand. Such uniformity in proportions is obtainable by feeding water and soap from equal levels, that is, from the tanks 2 and 6, respectively, having the same hydraulic head, into a zone of controlled suction at the pump inlet 26. The suction or vacuum in the pipe 24 is controlled by the size of the orifice 30 (or by the use of a pipe restricted in size, as indicated above).

In the operation of the present proportioning system, as the demand at the nozzles 76 changes, the vacuum on the inlet size of the pump 28 correspondingly changes, and since the rate of relative flow of water and soap varies with the changes in the vacuum, the same proportion of the two liquids is constantly maintained. In the absence of the orifice 40, the proportion of soap to water can be readily changed by simply adjusting the valve 42 to provide the percentage of concentration desired. Likewise, in the absence of any overriding control by the valve 32, the orifice 30 will automatically control the rate of supply of water to the pump 28.

It will be understood that if the pump 28 is to deliver only water, then the throttling valve 42 in the conduit 36 will be closed. It is further pointed out that in an installation where a fixed maximum amount of water is to be discharged, the pipe 24 may be made of the appropriate inside diameter and the fixed orifice 30 eliminated. The valve 32 may be eliminated or retained for use as a shut-off valve. The same applies to the conduit 36, which may have an inside diameter such as to provide the proportionate amount of soap to be mixed with the water. In such instance, the valve 42 is retained as a soap shut-off valve to effect rinsing with water alone.

In FIG. 2, parts corresponding to those in FIG. 1 have been identified by the same reference numerals. FIG. 2 illustrates a system somewhat similar to that shown in FIG. 1, but differs therefrom in that the liquid level 20a in the soap tank 6 is higher than the water level 18a in the water tank 2 by an amount indicated by the dimension X. This distance may be varied to compensate for the difference in the specific gravities of the water 4 and the particular liquid soap 6 that is being used, whereby substantially equal hydrostatic heads may be provided in the conduit 36 and the pipe 24.

The system in FIG. 2 further differs from that shown in FIG. 1 in that a one-way check valve 80 is shown connected in the soap conduit 36 and a similar one-way check valve 82 is connected in the pipe 24. The check valves 80 and 82 permit flow only in a direction away from the soap tank 6 and the water tank 2, respectively, so that no interchange of soap and water can occur between the tanks 2 and 6, regardless of the difference in the liquid levels 18a and 20a, and in the hydrostatic heads provided in the pipe 24 and conduit 36. Also in FIG. 2, the valve 42 is adjustable and serves as a variable orifice for proportioning the rate of flow of soap relative to the volume of water drawn through the orifice 30, regardless of the difference in the specific gravities of the soap and water and regardless of the difference in the liquid levels 18a and 20a.

FIG. 2 further differs from FIG. 1 in that a conventional positive displacement pump 28a is shown in place of the centrifugal pump 28. A by-pass pipe 84 containing a pressure relief valve 86 is connected around the pump 28a to permit by-passing of liquid when there is no demand on the system.

The system of FIG. 2 still further differs from that of FIG. 1 in that a single wash area 88 is shown instead of four stalls. The four cleaning nozzles 76 are shown connected with a manifold 54a so that they can all service the wash area 88. The arrangement shown is useful for washing a large vehicle, shown diagrammatically in dot-and-dash lines and identified by the numeral 90. The vehicle 90 may be a truck, bus, earth-moving equipment, aircraft, etc.. With the arrangement shown, four men can simultaneously work on the vehicle 90 to effect washing and subsequent rinsing thereof. In this connection, a remote control switch 92 is located adjacent the cleaning area 88 and is connected by conductors 94 and 96 to a solenoid-operating valve 98 connected in the soap conduit 36 between the variable orifice valve 42 and the check valve 80. Current for operating the valve 98 is supplied through lines 100 and 102. Thus, when the switch 92 is closed, it will effect closing of the solenoid valve 98 so that all flow of soap to the pump 28a is discontinued, and only water is supplied to the cleaning nozzles 76 to wash or rinse the vehicle 90. Of course, a similar result could be effected by closing the valve 42, but the remote control switch 92 is a great convenience when the cleaning nozzles 76 are located a substantial distance from the valve 42.

The proportioning system shown in FIG. 2 functions in the same manner described in connection with FIG. 1. However, the orifice 30 can be omitted and the valve 32 used as an adjustable orifice to regulate the proportion of water to soap flow permitted by adjustment of the valve 42 functioning as a variable soap orifice.

While four cleaning nozzles 76 have been shown in the systems of both FIG. 1 and FIG. 2, it will be understood that the proportioning apparatus may be associated with a single nozzle, or any number of nozzles in association with a pump of suitable capacity.

It will be understood that various changes may be made in the design, proportions, and arrangement of the components of the present systems without departing from the principles of the invention.

Claims

I claim:

1. Proportioning apparatus for continuously providing a uniform mixture of different liquids, comprising: a first tank to receive one liquid; a second tank to receive a second liquid; means connected with each of said tanks for automatically maintaining a supply of liquid in said tanks; a pump having an inlet and an outlet; first pipe means connecting said first tank with said pump inlet and providing a first prescribed flow restriction to proportion the flow of said first liquid; conduit means connected between said second tank and said first pipe means and providing a second prescribed flow restriction to proportion the flow of said second liquid; and a second pipe connected with said pump outlet for supplying the proportioned mixture of liquids to a place of use.

2. Apparatus as defined in claim 1, wherein the automatic means which supplies liquid to the tanks maintains a predetermined relative level of the liquid in said tanks.

3. Apparatus as defined in claim 1, wherein the liquids in the two tanks have the same specific gravity and wherein the liquid level in the two tanks is substantially equal to provide substantially equal hydraulic heads.

4. Apparatus as defined in claim 1, wherein the liquids in the two tanks have different specific gravities and wherein the liquid levels in the two tanks are unequal but are such as to provide substantially equal hydraulic heads.

5. Apparatus as defined in claim 1, wherein the liquid in the first tank is water and the liquid in the second tank is a liquid soap.

6. Apparatus as defined in claim 5, wherein a solenoid-operated valve is connected in the conduit means and a switch is connected in circuit with said valve to operate the same to shut off flow of soap from the second tank.

7. Apparatus as defined in claim 1, wherein a vacuum gauge is connected in the first pipe means at a point between the pump and the conduit means connected to the second tank to indicate the pump suction.

8. Apparatus as defined in claim 1, wherein the flow restriction in the first pipe means is provided by an orifice of fixed size.

9. Apparatus as defined in claim 1, wherein the flow restriction in the conduit means is provided by an adjustable throttling valve.

10. Apparatus as defined in claim 1, wherein the flow restriction in the first pipe means is provided by an orifice of fixed size, and wherein the flow restriction in the conduit means is provided by an adjustable throttle valve which can be adjusted to vary the proportion of the second liquid relative to the first liquid and which can be closed, if desired, to limit delivery by the pump of only the first liquid.

11. Apparatus as defined in claim 1, wherein the flow restriction in the first pipe means is provided by an adjustable throttle valve.

12. Apparatus as defined in claim 1, wherein the flow restriction in the conduit means is provided by an orifice of fixed size.

13. Apparatus as defined in claim 1, wherein the flow restriction in the first pipe means is provided by an adjustable throttle valve, and wherein the flow restriction in the conduit means is provided by an orifice of fixed size, said throttle valve being adjustable to vary the proportion of the first liquid relative to the second liquid and which can be closed, if desired, to limit delivery by the pump of only the second liquid.

14. Apparatus as defined in claim 1, wherein the flow restriction in the first pipe means is provided by an orifice of fixed size, and wherein an adjustable throttle valve is also connected in said first pipe means to reduce the flow of the first liquid to less than that permitted by said fixed orifice, and/or to completely shut off flow from the first tank, when desired; and wherein the flow restriction in the conduit means is provided by an orifice of fixed size, and wherein an adjustable throttle valve is also connected in said conduit means to reduce the flow of the second liquid to less than that permitted by the fixed orifice in said conduit, and/or which can be completely closed to shut off all flow from the second tank, when desired.

15. Apparatus as defined in claim 1, wherein the restriction of flow in the first pipe means and conduit means, respectively, is provided by the size of said pipe means and conduit means.

16. Apparatus as defined in claim 1, wherein a check valve is connected in the first pipe means and in the conduit means to prevent liquid interflow between the first and second tanks.