Carbon dioxide dry cleaning system

Abstract

A carbon dioxide dry cleaning system features a pair of liquid carbon dioxide storage tanks in communication with a compressor. A sealed cleaning chamber contains the objects to be cleaned. By selectively pressurizing the storage tanks with the compressor, liquid carbon dioxide is made to flow to the cleaning chamber through cleaning nozzles so as to provide agitation of the objects being dry cleaned. Liquid carbon dioxide displaced from the cleaning chamber returns to the storage tanks. In an alternative embodiment, a single storage tank is pressurized via a compressor with gas from the cleaning chamber so that liquid solvent from the storage tank travels to the cleaning chamber through nozzles. The objects in the cleaning chamber are agitated by a rotating basket. After a prewash cycle, liquid solvent from the cleaning chamber is directed to a still. The liquid solvent in the still is boiled through a connection with the head space of the cleaning chamber. The still may be positioned within the storage tank and partially surrounded with a shroud for efficient heating of the still with gas from the cleaning chamber. During agitation, liquid solvent from the cleaning chamber may be heated and filtered.

1 - 9 . (canceled)  
   
   
       10 . A method for cleaning or sterilizing objects in a liquid fluid cleaning system comprising a high-pressure storing/working vessel, a cleaning chamber, and a low-pressure supply vessel, the method comprising the steps of: 
 (i) loading the cleaning chamber with objects to be cleaned or sterilized;    (ii) supplying cleaning fluid to the cleaning chamber from the low-pressure supply vessel by means of pressure difference;    (iii) supplying cleaning fluid to the cleaning chamber from the high-pressure storing/working vessel;    (iv) cleaning the objects in the cleaning chamber with the cleaning fluid;    (v) transferring cleaning fluid from the cleaning chamber to the high-pressure storing/working vessel; and    (vi) unloading the cleaned objects from the cleaning chamber.    
   
   
       11 . In a liquid fluid based cleaning system, comprising a high-pressure customer application system including a cleaning chamber and a storing/working tank interconnected via a first tube system, a method for the cleaning or sterilizing of objects, e.g., garments, fabrics, substrates, complex materials or the like, comprising the steps of: 
 (i) loading the objects to be cleaned or sterilized into the cleaning chamber;    (ii) closing the cleaning chamber;    (iii) evacuating major part of the air in the cleaning chamber;    (iv) supplying a predetermined amount of cleaning fluid, pure or with additives, to the cleaning chamber from a customer supply system including a low-pressure liquid supply tank with cleaning fluid, pure or with additives, of a pressure higher than the present cleaning chamber pressure via a second tube system by simply, during a predetermined period of time, opening a valve of said second tube system;    (v) cleaning or sterilizing the objects by, during a predetermined period of time, circulating cleaning fluid, pure or with additives, or by agitating the objects;    (vi) emptying the cleaning chamber from major part of the cleaning fluid by transfer it to the storing/working tank;    (vii) opening the cleaning chamber, and thereby letting a predetermined amount of cleaning fluid leave the application system, which amount corresponds mainly to the supplied amount of cleaning fluid or to the supplied amount of cleaning fluid divided by some integer; and    (viii) unloading the cleaned or sterilized objects.    
   
   
       12 . The method as defined in  claim 11 , comprising choosing carbon dioxide as the cleaning fluid.  
   
   
       13 . The method as defined in  claim 12 , wherein the step of supplying comprises transferring the predetermined amount of carbon dioxide completely, or at least to a major extent, in its liquid phase.  
   
   
       14 . The method as defined in  claim 11 , wherein the low-pressure liquid supply tank is located remote from the application system to allow for installation of the customer application system in a cramped space.  
   
   
       15 . The method as defined in  claim 11 , wherein the low-pressure liquid supply tank has a filling means including an outdoors mounted connection socket in its far end, and wherein the liquid supply tank is filled through the connection socket from a low-pressure distribution unit, comprising a mobile tank, at time intervals, e.g., of one or two weeks.