GB2247191A

GB2247191A - Water treatment

Info

Publication number: GB2247191A
Application number: GB9116447A
Authority: GB
Inventors: Geoffrey Amatt-Carter
Original assignee: KIRTON ENGINEERING Ltd
Current assignee: KIRTON ENGINEERING Ltd
Priority date: 1990-08-03
Filing date: 1991-07-31
Publication date: 1992-02-26
Also published as: GB9116447D0

Abstract

A recycling plant is provided for water from a vehicle wash. The plant has an inlet pipe 10 loading to a storage tank 12 from which water is pumped to a three compartment main tank 18. The tank 18 is connected to a reverse osmosis assembly 28 comprising a relatively long tubular semi permeable membrane. The product from the assembly 28 is fed into a rinse storage tank 32. The discharge from the assembly 28 returns to the tank 18. The plant also includes an activated carbon filter 36 and a blend valve 38 for blending water from the tanks 20 and 32. Means are preferably provided for applying an electric potential across the membrane to vary the osmotic pressure. <IMAGE>

Description

Water Treatment This invention relates to water treatment and particularly but not exclusively to recycling water from a vehicle wash.

It is often required to recycle water from a vehicle wash in order to reduce water consumption and also effluent discharge. A problem encountered with vehicle washes, whether using recycled or mains water, is that dissolved solids in the water tend to prodLce "spotting" i.e. spots on the vehicle body. These spots may be of, for example, aluminium, sulphate, chlorine, sodium or detergents. Accordingly, to obviate or reduce this problem requires the reduction of the dissolved solids content in at least the water used to rinse the vehicle at the end of the wash programme.

According to the present invention there is provided vehicle wash apparatus comprising means for passing at least part of the water used therein across a semi permeable membrane to provide a product with reduced dissolved solids content which is used to rinse the vehicle.

Also according to the present invention there is provided water treatment apparatus for recycling used water in a vehicle wash, the apparatus comprising a semi permeable membrane providing a product with reduced dissolved solids content.

Means are preferably provided for applying an electric potential across the membrane such that the osmotic pressure thereacross can be varied.

The membrane is preferably cylindrical and may be substantially coaxially located in a tube with an inlet delivering water at one end of the tube to the interior of the membrane, an outlet for the product on the perimeter of the tube, and an outlet for the discharge at the other end of the tube.

Means may be provided for recirculating the water discharged from the tube. The membrane may be pleated.

The membrane is preferably connected such that the product therefrom is used for the final rinse of a vehicle. Means may be provided for blending said product with other water.

Means may be provided for filtering the water and this may be provided upstream of the membrane. The filtration means may comprise a hydrocyclone and/or an activated carbon filter and means may be provided for recirculating water through the filter means.

An electrode chamber through which the water passes having an anode and cathode may be provided, and this may be located upstream of the membrane. Means may be provided for recirculating water through the chamber.

The anode may be made of aluminium and the cathode made of steel.

Further according to the present invention there is provided a method of treating water from a vehicle wash comprising passing the water across a semi permeable membrane to provide a product with a reduced dissolved solids content.

The water is preferably also filtered and this is desirably carried out upstream of the membrane.

The water may also be passed through an electrode chamber having an anode or cathode, and the chamber is desirably located upstream of the membrane.

Water may be recycled through any of the membrane, filter, or electrode chamber.

The invention still further provides a method of washing a vehicle in a vehicle wash wherein at least some of the water used therein is first passed over a semi permeable membrane to produce a product for washing with a reduced dissolved solids content.

Said product is preferably only used to rinse the vehicle in the wash.

Embodiments of the present invention will now be described by way of example only with reference to Figures 1 to 6 of the accompanying drawings which each show a schematic diagram of a respective recycling plant for water from a vehicle wash.

The plant in Fig. 1 shows a pipe 10 leading from a vehicle wash bay to a collection storage tank 12. A pipe 14 containing a pump 16 leads from the tank 12 to a main tank 18 which is divided into three compartments; a wash compartment 20, middle compartment 22 and rinse compartment 24. The wash compartment 20 providing weiring over to the middle compartment 22 which provides weiring over to the rinse water compartment 24. The pipe 14 leads into the wash compartment 20.

The wash compartment 20 is connected through a pump 26 to a reverse osmosis assembly 28. The assembly 28 comprises a relatively long tube containing a tubular semi permeable membrane. Water is passed into one end of the tube and the filtrate passes through the membrane through an outlet 30 on the outside of the tube into a rinse storage tank 32. The water entering the tank 32 has a considerably reduced dissolved solids content. The water not passing through the membrane passes through an outlet at the far end of the tube back into the wash compartment 20 thus providing for recirculation through the assembly 28. The middle compartment 22 connects via a pump 34 to an activated carbon filter 36 for removal of detergent from the water. The output of the filter 36 passes into the compartment 24.Fresh water intake into the system passes into the middle compartment 22 through a break tank 37 and sensors are provided to indicate when such water is required.

The tank 32 and compartment 24 are connected together via a blend valve 38 which connects with a further valve 40. The wash compartment 20 also connects to the valve 40 the outlet of which leads via a pump 42 to the vehicle wash.

In use, water for washing passes directly from the compartment 20. As this water has not passed through the filter 36 there will already be some detergent in the water therefore providing a saving therein. For rinsing a blend suitable for the particular situation can be achieved by operation of the valve 38. This blend would depend on a number of conditions including the amount of dissolved solids in the mains water at the particular location. The water from the tank 32 provides for considerably reduced 'spotting' on the vehicle.

In this plant the filtrate from the assembly 28 is not used for washing but only for rinsing thus reducing the required capacity of the assembly 28. The blending providing by the valve 38 enables a blend with the required minimum permissible amount of dissolved solids to be used, again preventing over use of the osmosis assembly 28 thus reducing the cost of use and installation of the plant.

Fig. 2 shows a similar plant but with a hydrocyclone 44 downstream of the tank 12. The hydrocyclone 44 provides for an initial filtration of the water to remove solids suspended therein. The filtrate from the hydrocyclone 44 passes into the compartment 20 whilst the waste therefrom returns to the tank 12.

In the plant illustrated in Fig. 3 the reverse osmosis assembly 28 is situated immediately downstream of the mains inlet for topping up the plant. The reject from the assembly 28 is directly discharged. This plant also includes an electrode chamber 46 which receives water from the wash compartment 20 via a pump 48. The chamber 46 has aluminium anodes and steel cathodes charged at a nominal 12 V DC. The aluminium anodes produce aluminum ions which break down and remove wax from the water. The discharge from the chamber 46 returns to the compartment 20 thereby providing recirculation through the chamber 46. This plant would obviously be appropriate with vehicle washes which use wax.

The plant illustrated in Fig. 4 is similar to that in Fig. 3 except that the mains water passes through a break tank 36 into the middle compartment 22 as in the plant illustrated in Fig. 1. In the plant of Fig. 4 the reverse osmosis assembly 28 is fed from the middle tank 22 through a pump 50. The product from the assembly 28 passes into the rinse compartment 24 and the rejected water passes into the wash water compartment 20. In this plant there is no provision for blending as there is no separate rinse water tank. Further, no carbon filter is provided for removal of detergents. Accordingly in this plant the detergents will be removed by the assembly 28.

The plant of Fig. 5 is similar to that of Fig. 4 except that a rinse water tank 32 is provided which receives the product from the assembly 28. A carbon filter 36 is also provided which receives water from the middle compartment 22 and feeds water into the rinse water compartment 24. Blending is again provided by the valve 38.

The plant shown in Fig. 6 has two collection tanks 12A and B. The tank 12A is connected to a two compartment tank 52 having a wash water compartment 54 and rinse water compartment 56. The tank 12A connects with the tank 52 through a hydrocyclone 44. Water from the compartment 54 is recirculated through an electrode chamber 46 and may also be fed to the washing machine.

The tank 12B connects via a further hydrocyclone 58 to a carbon filter 36 and reverse osmosis assembly 28. The product from the assembly 28 passes into the rinse compartment 56 while the rejected water passes back into the tank 128. Water from the compartment 56 can be fed to the washing machine through a blend valve 60 permitting blending with water from the compartment 54.

Fresh water feeds directly into the compartment 56.

There is thus described a method and apparatus for providing water for a vehicle wash with a reduced dissolved solids contents, thus obviating spotting. As is described above in the different arrangements, the apparatus maybe such that only the water used for rinsing vehicles has the dissolved solids removed by reverse osmosis.

Various modifications other than those described above may be made. The reverse osmosis assembly may take a different form. Different arrangements of tanks and other types of filtration may be used.

Claims

1. Water treatment apparatus for recycling used- water in a vehicle wash, the apparatus comprising a semi permeable membrane providing a product with reduced dissolved solids content.

2. Vehicle wash apparatus comprising means for passing at least part of the water used therein across a semi permeable membrane to provide a product with reduced dissolved solids content which is used to rinse the vehicle.

3. Apparatus according to Claims 1 or 2, in which means are provided for applying an electric potential across the membrane such that the osmotic pressure thereacross can be varied.

4. Apparatus according to any of Claims 1 to 3, in which the membrane is cylindrical.

5. Apparatus according to claim 4, in which the membrane is substantially coaxially located in a tube with an inlet delivering water at one end of the tube to the interior of the membrane, an outlet for the product on the perimeter of the tube, and an outlet for the discharge at the other end of the tube.

6. Apparatus according to Claim 5, in which means are provided for recirculating the water discharged from the tube.

7. Apparatus according to Claims 5 or 6, in which the membrane is connected such that the product therefrom is used for the final rinse of a vehicle.

8. Apparatus according to any of Claims 5 to 7, in which means are provided for blending the product with other water.

9. Apparatus according to any of the preceding Claims, in which the membrane is pleated.

10. Apparatus according to any of the preceding Claims, in which means are provided for filtering the water.

11. Apparatus according to Claim 10, in which the filtering means are provided upstream of the membrane.

12. Apparatus according to Claims 10 or 11, in which the filtration means comprises a hydrocyclone and/or an activated carbon filter.

13. Apparatus according to any of Claims 10 to 12, in which means are provided for recirculating water through the filter means.

14. Apparatus according to any of the preceding Claims, in which an electrode chamber having an anode and cathode is provided through which the water passes.

15. Apparatus according to Claim 14, in which the electrode chamber is located upstream of the membrane.

16. Apparatus according to Claims 14 or 15, in which means are provided for recirculating water through the chamber.

17. Apparatus according to any of claims 14 to 16, in which the anode is made of aluminium and the cathode made of steel.

18. Vehicle wash apparatus comprising used water treatment apparatus for recycling water used in the wash, the water treatment apparatus being according to any of Claims 3 to 17 when dependent of Claim 1.

19. A method of treating water from a vehicle wash comprising passing the water across a semi permeable membrane to provide a product with a reduced dissolved solids content.

20. A method according to Claim 19, in which the water is also filtered.

21. A method according to Claim 20, in which the filtration is carried out upstream of the membrane.

22. A method according to any of Claims 19 to 21, in which water is recycled through the filter.

23. A method according to any of Claims 19 to 22, in which the water is also passed through an electrode chamber having an anode or cathode.

24. A method according to Claim 22, in which the chamber is located upstream of the membrane.

25. A method according to Claims 23 or 24, in which water is recycled through the electrode chamber.

26. A method according to any of Claims 19 to 25, in which water is recycled through the membrane.

27. A method of washing a vehicle in a vehicle wash wherein at least some of the water used therein is first passed over a semi permeable membrane to produce a product for washing with a reduced dissolved solids content.

28. A method according to Claim 27, in which the product is only used to rinse the vehicle in the wash.

29. Vehicle washing apparatus substantially as hereinbefore described with reference to any one of the accompanying drawings.

30. Water treatment apparatus substantially as hereinbefore described with reference to any one of the accompanying drawings.

31. A method of treating water from a vehicle wash substantially as hereinbefore described with reference to any one of the accompanying drawings.

32. A method of washing a vehicle in a vehicle wash substantially as hereinbefore described with reference to any one of the accompanying drawings.

33. Any novel subject matter or combination including novel subject matter disclosed in the foregoing specification or claims and/or shown in the drawings, whether or not within the scope of or relating to the same invention as any of the preceding claims.