System and method for solvent recovery and purification in a low water or waterless wash

• US 20030196282A1
• Filed: 12/30/2002
• Published: 10/23/2003
• Est. Priority Date: 04/22/2002
• Status: Active Grant

• Current Assignee: Haier US Appliance Solutions, Inc. DBA GE Appliances (Haier Group Company)
• Original Assignee: General Electric Company
• Inventors: Fyvie, Thomas Joseph, Rocha, Teresa Grocela, Shoemaker, Philip Alexander, Hallman, Darren Lee
• Granted Patent: US 7,210,182 B2
• Time in Patent Office: Days
• US Class Current: 15/3
• CPC Class Codes: D06F 43/08 Associated apparatus for handling and recovering the solvents
• CPC Class Codes: D06F 43/085 Filtering arrangements; Filter cleaning; Filter-aid powder dispensers
• CPC Class Codes: D06F 43/086 Recovering the solvent from the drying air current

Abstract

Method and apparatus for recovering and purifying a solvent used in an article cleaning appliance are provided. The method allows passing solvent-based cleaning fluid from a wash basket through a coarse filter configured to remove relatively large particulates from the cleaning fluid. The method further allows passing cleaning fluid from the coarse filter through a particulate filter configured to remove relatively fine particulates from the cleaning fluid. An aqueous phase that may be present in the cleaning fluid is separated by decanting and coalescing through a separator/filter assembly. The cleaning fluid may then be passed through a regeneration cartridge for removing any water that may remain in the cleaning fluid, and for adsorbing organic contaminants that may be present in the cleaning fluid. Recovered solvent may be stored in a tank for subsequent use in a cleaning process performed by the appliance.

Claims

1. An article cleaning apparatus comprising:

an air management mechanism;

a cleaning basket assembly;

a fluid regeneration device;

a working fluid device coupled to said fluid regeneration device, said cleaning basket assembly, and said air management mechanism, said working fluid device comprising a fluid filter/separator assembly for substantially removing an aqueous phase that may be present in a solvent-based cleaning fluid that passes therethrough;

a clean fluid device coupled to said cleaning basket assembly and said fluid regeneration device; and

a controller coupled to said air management mechanism, said cleaning basket assembly, said working fluid device, said regeneration device, and said clean fluid device;

wherein said controller is configured to control a cleaning process.

2. The apparatus of claim 1 wherein said filter/separator assembly comprises a decanting stage and a filter stage.

3. The apparatus of claim 2 wherein the filter stage comprises a filter element coated with a hydrophobic material.

4. The apparatus of claim 3 wherein the filter element comprises an axially-pleated filter element to facilitate precipitation of water droplets that coalesce thereon.

5. The apparatus of claim 2 wherein the decanting stage comprises a turbine centrifuge configured to separate a higher density fluid from a lower density fluid, wherein the higher density fluid comprises the aqueous phase that may be present in the solvent-based cleaning fluid, and the lower density fluid comprises cyclic siloxane solvent.

6. The apparatus of claim 5 wherein the filter stage is configured to substantially block passage to any aqueous phase that passes from the decanting stage.

7. The apparatus of claim 1 wherein the cleaning fluid further comprises a cleaning agent selected from the group consisting of sanitizing agents, emulsifiers, surfactants, detergents, bleaches, softeners, and any combination thereof.

8. The apparatus of claim 2 wherein the filter stage comprises a filter element having a pore size ranging from about 2 to 30 microns.

9. The apparatus of claim 1 wherein the cleaning fluid passes through the filter-separator assembly at a flow rate ranging from about 400 ml/min to about 1300 ml/min.

10. Apparatus for purifying and recovering a solvent used in an article cleaning appliance comprising:

a coarse filter coupled to receive solvent-based cleaning fluid from a wash basket, the coarse filter configured to remove relatively large particulates from the cleaning fluid;

a particulate filter coupled to receive cleaning fluid from the coarse filter, the particulate filter configured to remove relatively fine particulates from the cleaning fluid;

a fluid filter/separator assembly coupled to receive cleaning fluid from the particulate filter, the assembly configured to separate an aqueous phase that may be present in the cleaning fluid;

a regeneration cartridge coupled to receive cleaning fluid from the filter/separator assembly, the regeneration cartridge comprising water adsorption media for removing any water that may remain in the cleaning fluid, the regeneration cartridge further comprising adsorption media configured to adsorb organic contaminants that may be present in the cleaning fluid; and

a tank for storing recovered solvent for subsequent use in a cleansing process performed by the appliance.

11. The apparatus of claim 10, wherein the water adsorption media comprises materials selected form the group consisting of calcined clay, water adsorbing polymers, sodium sulfate, paper, cotton fiber, lint, and any combination thereof.

12. The apparatus of claim 10, wherein the organic adsorption media comprises materials selected from the group consisting of activated charcoal, carbon, carbon nanotubes, calcined clay, Kaolinite, adsorption resins, carbonaceous type resins, silica gels, alumina in acid form, alumina in base form, alumina in neutral form, zeolites, mol seives, and any combination thereof

13. The apparatus of claim 10 wherein the coarse filter, the particulate filter, the filter/separator assembly, and the regeneration cartridge comprise a unitary assembly.

14. The apparatus of claim 10 wherein the coarse filter, the particulate filter, the filter/separator assembly, and the regeneration cartridge comprise individualized components.

15. The apparatus of claim 10 wherein the cleaning fluid comprises cyclic siloxane solvent plus approximately 0.25 to 15% of a polar solvent.

16. The apparatus of claim 15 wherein the polar solvent comprises water.

17. The apparatus of claim 15 wherein the cleaning fluid further comprises approximately approximately 0.01 to 0.5% detergent by weight of a total fluid charge.

18. A method for recovering and purifying a solvent used in an article cleaning appliance, the method comprising:

passing solvent-based cleaning fluid from a wash basket through a coarse filter configured to remove relatively large particulates from the cleaning fluid;

passing cleaning fluid from the coarse filter through a particulate filter configured to remove relatively fine particulates from the cleaning fluid;

separating an aqueous phase that may be present in the cleaning fluid by decanting and coalescing of fluid through a separator/filter assembly;

passing the cleaning fluid through a regeneration cartridge for removing any water that may remain in the cleaning fluid, and for adsorbing organic contaminants that may be present in the cleaning fluid; and

storing recovered solvent in a tank for subsequent use in a cleaning process performed by the appliance.

19. The method of claim 18 wherein the cleaning fluid is processed at a first flow rate selected to partially remove contaminants present therein while the appliance performs an ongoing operational cycle to be followed by a successive operational cycle, and wherein cleaning fluid is subsequently processed at a second flow rate selected to remove any remaining contaminants, wherein the first flow rate is sufficiently fast relative to the second flow rate so that partially purified cleaning fluid may be available for any successive operational cycles of the appliance.

20. The method of claim 18 comprising a first solvent-purifying iteration wherein cleaning fluid is passed at a first flow rate through the coarse and particulate filters for removing particulates present therein, the method further comprising a second solvent-purifying iteration wherein cleaning fluid is subsequently passed at a second flow rate through the regeneration cartridge, wherein the first flow rate is sufficiently fast relative to the second flow rate so that partially purified cleaning fluid from the first iteration may be available on demand for any successive operational cycle of the appliance without having to wait for completion of the second iteration.

21. The method of claim 19 further comprising diluting partially purified cleaning fluid with purified cleaning fluid, wherein the volume of purified solvent comprises at least 50% of the volume of the partially purified cleaning fluid.

22. The method of claim 20 further comprising diluting partially purified cleaning fluid with purified cleaning fluid, wherein the volume of purified solvent comprises at least 50% of the volume of the partially purified cleaning fluid.

23. The method of claim 18 wherein a first portion of the solvent-based cleaning fluid used for a next operational cycle of the appliance comprises solvent recovered from an ongoing operational cycle, and a second portion of the cleaning fluid comprises purified solvent extracted from the storage tank, whereby the volume of the first portion is sufficiently high relative to the volume of the second portion to avoid use of a relatively large storage tank, and further whereby the volume of the first portion is sufficiently low relative to the volume of the second portion to avoid a relatively high flow rate for processing the recovered solvent.

24. The method of claim 22 wherein the volume of the first portion of the cleaning fluid recovered from an ongoing operational cycle comprises about 45% relative to the volume extracted from the storage tank.

25. The method of claim 19 wherein the first flow rate comprises about 1300 ml/min, the second flow rate comprises about 650 ml/min, the tank size comprises about 38 liters, and total cycle time for processing the cleaning fluid comprises about 90 minutes.

26. The method of claim 18 wherein the cleaning fluid is processed at a single flow rate selected to remove contaminants present therein while the appliance performs an ongoing operational cycle, wherein the single flow rate comprises a relatively slower value, thereby providing a relatively longer cycle time for processing the fluid.

27. The method of claim 25 wherein the single flow rate comprises about 650 ml/min, and the cycle time for processing the fluid comprises about 100 minutes.

28. The method of claim 18 wherein the cleaning fluid is processed at a single flow rate selected to remove contaminants present therein while the appliance performs an ongoing operational cycle, wherein the single flow rate comprises a relatively slower value, and in combination with a relatively larger tank size avoids extending a cycle time for processing the fluid.

29. The method of claim 27 wherein the single flow rate comprises about 650 ml/min, the tank size comprises about 57 liters, and the cycle time for processing the fluid comprises about 90 minutes.