GB2262455A

GB2262455A - Chemical solution applicator

Info

Publication number: GB2262455A
Application number: GB9223994A
Authority: GB
Inventors: Steven W James
Original assignee: Techtron Ltd Great Britain
Current assignee: Techtron Ltd Great Britain
Priority date: 1991-11-15
Filing date: 1992-11-16
Publication date: 1993-06-23
Anticipated expiration: 2012-11-16
Also published as: GB9223994D0; GB2262455B

Abstract

A chemical solution (mixture or suspension) applicator system 10 comprises a first pump 12 which, in use, pumps water to a system outlet at 14. A peristaltic pump 24 is used to dose a chemical from a supply 13 into the water (at 26) before leaving the system outlet 14. The pump 12 is a low volume pump, i.e. it delivers less than 4 litres per minute. The relative pumping rates of the pumps 12, 24 are controlled to maintain a desired chemical concentration in the water leaving the outlet 14. The applicator can be used for washing vehicles, or for cleaning food factories and food handling equipment. <IMAGE>

Description

Chemical Solution Applicator System The present invention relates to chemical solution applicator systems.

Applicator systems for chemical solutions are used for coating surfaces with chemical solutions for a variety of purposes. One of these includes cleaning commercial vehicles. This process is commonly known as "traffic film removal". Traffic film removal is conventionally performed by applying a coating of cleaning chemical solution to the vehicle and then rinsing with water. The chemical solution is sometimes applied at low pressure (typically 200 to 300 pounds per square inch or about 13pud to 2000 kPa) through a hand-held hose and lance delivering a solution of the chemical in water, at high volume, usually at least 8 litres per minute, but often much greater.After the vehicle has been coated with the solution of cleaning chemical, the supply pressure is increased, typically to 1,000 to 2,000 pounds per square inch (about 6800 to 13800 kpaj, to spray off the cleaning solution and dirt.

All this is usually carried out with a conventional pressure washer. Traffic film removal uses a considerable amount of water per vehicle and this must all be treated to remove the cleaning chemicals and dirt.

Similar problems arise in other situations in which applicator systems are used.

The present invention seeks to provide an improved system for applying chemical solutions.

The invention provides a chemical solution applicator system comprising a first pump which, in use, pumps water to a system outlet, and dosing means operable to introduce a chemical into the water before leaving the system outlet, wherein the first pump is a low volume pump as defined herein.

The first pump and the dosing means are so linked as to control the rate of introduction of chemical by the dosing means in dependence on the pumping rate of the first pump, whereby to maintain a desired chemical concentration in the water leaving the system outlet.

The invention also provides a chemical solution applicator system comprising a first pump means which, in use, pumps water to a system outlet, and dosing means operable to introduce a chemical into the water before leaving the system outlet, wherein the first pump means and the dosing means are so linked as to control the rate of introduction of the chemical by the dosing means in dependence on the pumping rate of the first pump, whereby to maintain a desired chemical concentration in the water leaving the system outlet.

The first pump may be a low volume pump.

Preferably the dosing means comprises a second pump operable to pump the chemical into the water. The second pump is preferably a peristaltic pump.

The system may comprise control means operable to control the pumping rates of the first and second pumps.

The control means are preferably operable to change the relative pumping rates of the pumps. The control means may comprise timer means operable to disable the system a predetermined time after pumping begins. The control means is preferably operable to allow the predetermined time to be varied.

The system may comprise a plurality of inlets for chemicals, the dosing means being operable to select a chemical or chemicals from the available chemicals for introduction into the water.

The first pump is preferably a low pressure pump as defined herein. The first pump, the dosing means and the control means are preferably contained within a lockable container.

The invention also provides a method of applying a chemical solution in which the chemical is introduced into water to form a solution which is applied by means of a pump to the article to be cleaned, wherein the pump is a low volume pump as defined herein.

Preferably, the rate of introduction of chemical is controlled in dependence on the pumping rate of the first pump, whereby to maintain a desired chemical concentration in the water leaving the system outlet.

The invention also provides a method of applying a chemical solution in which the chemical is introduced into water to form a solution which is applied by means of a first pump to an outlet, wherein the introduction of the chemical is controlled in dependence on the pumping rate of the first pump, whereby to maintain a desired chemical concentration in the water leaving the system outlet.

The first pump is preferably a low volume pump.

A second pump may be used to pump the chemical into the water. The second pump may be a peristaltic pump.

The pumping rates of the first and second pumps are preferably controlled together. The relative pumping rates of the pumps may be able to be changed. Timer means may be used to stop pumping a pre-determined time after pumping begins. The pre-determined time can preferably be varied.

The chemical or chemicals to be introduced into the water may be selected from a plurality of available chemicals.

A low pressure pump may be used as the first pump.

The solution is preferably subsequently rinsed away. The solution may be rinsed by means of a high volume water supply. The solution may be rinsed by means of a high pressure water supply.

The chemical solution is preferably applied by means of a system according to the first or second aspect of the invention.

An example of a system according to the present invention will now be described in more detail, by way of example only, and with reference to the accompanying drawing which is a highly schematic diagram of the system.

Turning to Fig. 1, there is shown a chemical solution applicator system 10 comprising a first pump 12 which, in use, pumps water to a system outlet at 14.

Dosing means indicated generally at 16 are operable to introduce (or "dose") a chemical from a supply at 18 into the water before leaving the system outlet 14. The first pump 12 is a pump which, in use, delivers less than 4 litres per minute. A pump whose delivery is below this figure is referred to herein as a low volume pump.

In more detail, the system 10 includes a water inlet 20 from a water supply. The inlet 20 is connected through a pipe 22 to the pump 12 and then to the outlet 14. Cleaning chemicals are available from a supply 18 and are pumped by a peristaltic pump 24 along a pipe 26 which joins the pipe 22 between the inlet 20 and the pump 12.

The operation of the pumps 12,24 are controlled by a control circuit 28. The control circuit 28 controls the relative pumping rates of the pumps 12,24. This allows the volume of chemical entering the pipe 22 to be controlled in relation to the volume of water passing along the pipe and consequently, the concentration of chemical leaving the outlet 14 is controlled. Moreover, the nature of a peristaltic pump allows the delivery of chemical to be accurately controlled, so that the final solution strength is accurately controlled.

In a possible modification, there may be more than one chemical available at the inlet 18, for introduction separately or in combination to the pipe 22, under the control of a single pump 24. Alternatively, a separate pump may be provided for each chemical.

The control circuit 28 incorporates a timer to control the length of time for which the pumps 12,24 can operate. At the end of the predetermined time, the pumps are disabled.

The control circuit 28 and the pumps 12,24 are housed > :ithin a cabinet or container 30, preferably o n e which can be locked to prevent unauthorised personnel tampering with the pumps or control circuit. This ensures that once the control circuit 28 has been set to control the pumps to deliver a required chemical concentration for an appropriate time period, these parameters cannot be changed except by authorised personnel who can unlock the container 30.

For safety reasons, the control circuit 28 and pumps 12,24 are low voltage equipment, supplied from a transformer 32.

The pump 12 is a low pressure pump, delivering water at a pressure of no more than 250 pounds per square inch (about 1700 kPa).

The system described above can be used in the following manner for TFR (traffic film removal).

When a vehicle is to be cleaned, the system 10 is switched on by a control (not shown) accessible from outside the container 30. This causes the pumps 12,24 to begin pumping, to deliver a solution of controlled strength, to the outlet 14. This low volume, low pressure output can be supplied to a hand-held hose or wand which is used by the operator to direct the solution to the vehicle being cleaned. The low pressure and low volume allows the operator to apply an even film of solution over the whole surface of the vehicle. The use of low volume avoids excessive water being used and wasted and consequently, because of the concentration requirements, this also avoids wastage of chemicals.The use of low pressure and low volume, together with the provision of accurate chemical dosing to ensure accurate solution strengths, is expected to allow results to be optimised, in terms of chemical performance, water usage and chemical usage. However, the operator is encouraged not to work unduly slowly because the control circuit 28 will disable the system 10 after a period of time considered sufficient to adequately apply the chemical solution to the vehicle.

Once the system 10 has been disabled by the timer, the operator uses a conventional high pressure, high volume water supply to rinse the vehicle.

It is envisaged that by using the lockable container 30, chemical and water usage can be reduced in comparison with conventional systems. The operator cannot alter the concentration nor the time for which the solution is supplied.

Various modifications can be made to the apparatus described above with departing from the scope of the present invention. Various types of pump could be used and various control systems could be used. The water outlet is envisaged for supply to a hand-held wand, but other forms of outlet could be used.

It will be apparent from the above that a wide variety of chemical solutions could be applied by the system, including solutions of pure or mixed chemicals of many types. Consequently, the term "chemical" is used broadly, to encompass all these possibilities. The system can also be used to combine chemicals in other ways, for instance to make mixtures or suspensions rather than solutions, and the term "solution" should be interpreted sufficiently broadly to encompass these alternative possibilities. Among the uses envisaged for the apparatus are the application of biocides, algaecides, virucides etc., for instance in cleaning food factories, food handling equipment etc.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. A chemical solution applicator system comprising a first pump which, in use, pumps water to a system outlet, and dosing means operable to introduce a chemical into the water before leaving the system outlet, wherein the first pump is a low volume pump as defined herein.

2. A system according to claim 1, wherein the first pump and the dosing means are so linked as to control the rate of introduction of chemical by the dosing means in dependence on the pumping rate of the first pump, whereby to maintain a desired chemical concentration in the water leaving the system outlet.

3. A chemical solution applicator system comprising a first pump means which, in use, pumps water to a system outlet, and dosing means operable to introduce a chemical into the water before leaving the system outlet, wherein the first pump means and the dosing means are so linked as to control the rate of intoduction of the chemical b.

the dosing means in dependence on the pumping rate of the first pump, whereby to maintain a desired chemical concentration in the water leaving the system outlet.

4. A system according to claim 3, wherein the first pump is a low volume pump.

5. A system according to any preceding claim, wherein the dosing means comprises a second pump operable to pump the chemical into the water.

6. A system according to claim 5, wherein the second pump is a peristaltic pump.

7. A system according to claim 5 or 6, further comprising control means operable to control the pumping rates of the first and second pumps.

8. A system according to claim 7, wherein the control means are operable to change the relative pumping rates of the pumps.

9. A system according to claim 7 or 8, comprising timer means operable to disable the system a predetermined time after pumping begins.

10. A system according to claim 9, wherein the control means is operable to allow the predetermined time to be varied.

11. A system according to any preceding claim, further comprising a plurality of inlets for chemicals, the dosing means being operable to select a chemical or chemicals from the available chemicals for introduction into the water.

12. A system according to any of claims 7 to 11, wherein the first pump, the dosing means and the control means are contained within a lockable container,

1 3. A system according to any preceding claim, where in the first pump is a low pressure pump as defined herein.

14. A method of applying a chemical solution in which the chemical is introduced into water to form a solution which is provided by means of a first pump to an outlet, wherein the pump is a low volume pump as defined herein.

15. A method according to claim 14, wherein the rate of introduction of chemical is controlled in dependence on the pumping rate of the first pump, whereby to maintain a desired chemical concentration in the water leaving the system outlet.

16. A method of applying a chemical solution in which the chemical is introduced into water to form a solution which is applied by means of a first pump to an outlet, wherein the introduction of the chemical is controlled in dependence on the pumping rate of the first pump, whereby to maintain a desired chemical concentration in the water leaving the system outlet.

17. A method according to claim 16, wherein the first pump is a low volume pump.

18. A method according to any of claims 14 to 17, in which a second pump is used to pump the chemical into the water.

19. A method according to claim 18, wherein the second pump is a peristaltic pump.

20. A method according to claim 18 or 19, wherein the pumping rates of the first and second pumps are controlled together.

21. A method according to claim 20, wherein the relative pumping rates of the pumps may be changed.

22. A method according to any of claims 14 to 21, wherein timer means are used to stop pumping a predetermined time after pumping begins.

23. A method according to claim 22, wherein the pre-determined time can be varied.

24. A method according to any of claims 14 to 23, in which the chemical or chemicals to be introduced into the water are selected from a plurality of available chemicals.

25. A method according to any of claims 14 to 24, wherein a low pressure pump is used as the first pump.

26. A method according to any of claims 14 to 25, in which the solution is subsequently rinsed away.

27. A method according to claim 26, in which the solution is rinsed by means of a high volume water supply.

28. A method according to claim 25 or 27, in which the solution is rinsed by means of a high pressure water supply.

29. A method according to any of claims 14 to 28, in which the chemical solution is applied by means of a system according to any of claims 1 to 13.

30. A chemical solution applicator system substantially as described above, with reference to the accompanying drawing.

31. A method of applying a chemical solution, substantially as described above with reference to the accompanying drawing.

32. Any novel subject matter or combination including novel subject matter disclosed, whether or not within the scope of or relating to the same invention as any of the preceding claims.