Non-aqueous washing apparatus and method

Abstract

The invention relates to a non-aqueous washing machine, methods of using the machine, methods of washing, and recycling.

1 . A method of cleaning fabrics, including the steps of: 
 disposing a fabric load in a wash container;    delivering a wash liquor to said wash chamber, said wash liquor comprising a substantially non-reactive, non-aqueous, non-oleophilic, apolar working fluid and at least one washing adjuvant;    removing said wash liquor from said fabric load;    delivering a liquid extraction solvent to said fabric load;    removing said liquid extraction solvent from said fabric load; and    recovering the liquid extraction solvent and working fluid for reuse.    
   
   
       2 . The method of  claim 1  wherein the liquid extraction solvent has at least one of the following properties: 
 a KB Value less than 30,    a solubility in water of less than 10%, or    a flash point greater than 145 C.    
   
   
       3 . The method of  claim 2  wherein the liquid extraction solvent is selected from the group consisting of: perfluorocarbons, hydrofluoroethers, fluorinated hydrocarbons, fluoroinerts and carbon dioxide.  
   
   
       4 . The method of  claim 3  wherein the liquid extraction solvent is further selected from the group consisting of methoxynonafluorobutane, ethoxynonafluorobutane and mixtures thereof.  
   
   
       5 . The method of  claim 1  wherein said non-reactive, non-aqueous, non-oleophilic, apolar working fluid under standard conditions is further characterized by: 
 a KB value less than 30;    a surface tension less than approximately 35 dynes/cm 2 ; and    a solubility in water of less than 10%.    
   
   
       6 . The method of  claim 1  wherein the working fluid is selected from the group consisting of hydrofluoroethers, highly fluorinated hydrocarbons, volatile methyl siloxanes or mixtures thereof.  
   
   
       7 . The method of  claim 6  wherein the working fluid is further selected from decamethylcyclopentasiloxane, dodecamethylpentasiloxane, decamethyltetrasiloxane, octylmethylcyclotetrasiloxane, hexamethyldisiloxane, octamethyltrisiloxane, tetradecamethylhexasiloxane, hexadecamethylheptasiloxane, methyltris(trimethylsiloxane) silane or mixtures thereof.  
   
   
       8 . The method of  claim 1  wherein recovering the liquid extraction solvent and working fluid further comprises recovering the liquid extraction solvent before dissolved contaminants are removed from the working fluid.  
   
   
       9 . The method of  claim 8 , wherein the liquid extraction solvent is subjected to a treatment selected from the group consisting of: gravity separation, filtration, centrifugation, fractional distillation, freeze distillation, temperature reduction, adsorption, absorption, inducing electrical fields, vaporization, pressure reduction or mixtures thereof.  
   
   
       10 . The method of  claim 1  wherein the temperature of the working fluid never exceeds 30° F. below its flash point.  
   
   
       11 . The method of  claim 8  wherein the working fluid is further recovered from a wash liquor by sequentially performing the following treatments: treating the wash liquor either with carbon dioxide under pressure, performing temperature reduction, contacting it with a flocculating agent, adjusting its pH or contacting it with an ion exchange resin; and treating the effluent from the above step by means of one of the following materials: a dissolver, an emulsifier, an adsorption agent, an absorption agent, a soap, a pH shifter, a flocculating agent, a filtration material, a cake/drying material agent, by gravimetric means, by vortex separation, by distillation, by freeze distillation; treating the effluent from the above step with one of the following a coalescence agent, an absorption agent, an adsorption agent, a pH adjustment agent, an ion exchange resin; and treating the effluent from the above step by means of one of the following carbon dioxide under pressure, a flocculating agent, a pH adjuster, performing temperature reduction, an adsorption agent, an absorption agent, an ion exchange resin.  
   
   
       12 . The method of  claim 8  wherein the working fluid is further recovered from a wash liquor by sequentially performing the following treatments: treating the wash liquor either with carbon dioxide under pressure, performing temperature reduction, contacting it with a flocculating agent, adjusting its pH or contacting it with an ion exchange resin; treating the effluent from the above step with one of the following: a coalescence agent, an absorption agent, an adsorption agent, a pH adjustment agent, an ion exchange resin; then treating the effluent from the above step by means of one of the following materials: a dissolver, an emulsifier, an adsorption agent, an absorption agent, a soap, a pH shifter, a flocculating agent, a filtration material, a cake/drying material agent, by gravimetric means, by vortex separation, by distillation, by freeze distillation; and then treating the effluent by means of one of the following carbon dioxide under pressure, a flocculating agent, a pH adjuster, temperature reduction, an adsorption agent, an absorption agent, an ion exchange resin.  
   
   
       13 . The method of  claim 1  wherein after recovering the liquid extraction solvent and working fluid, they are stored separately for reuse.  
   
   
       14 . The method of  claim 8  wherein after recovering the liquid extraction solvent, the liquid extraction solvent contains less than 25% working fluid.  
   
   
       15 . The method of  claim 1  wherein the liquid extraction solvent and wash liquor undergo a treatment step to reduce the amount of dissolved contaminants.  
   
   
       16 . The method of  claim 15  wherein the treatment step is further characterized by a temperature reduction step.  
   
   
       17 . The method of  claim 16  wherein the temperature reduction step reduces the temperature to the freezing point of at least one of the solvents in the mixture.  
   
   
       18 . The method of  claim 16  wherein the treatment step is further characterized by passing the liquid extraction solvent and wash liquor through a filtration means.