Patent ID: 6165282
Filing Date: 2000-12-26
Classification: B08B

Abstract:
A method for removing contaminants from a substrate comprising:placing a substrate comprising contaminants in a pressure vessel;supplying to said pressure vessel a solvent fluid adapted to remove said contaminants;heating a first zone of said pressure vessel to an unstable elevated temperature effective tofacilitate a first convective flow of said solvent fluid through said first zone and into a second zone of said pressure vessel;cooling said second zone of said pressure vessel to a cooled temperature effective to facilitate a second convective fluid flow of said solvent fluid through said second zone and into said first zone of said pressure vessel, said cooled temperature also being effective to reduce solubility of said contaminants in said solvent fluid to a level sufficient to cause at least a portion of said contaminants to precipitate from said solvent fluid without requiring depressurization of said pressure vessel;providing sufficient thermal insulation between said first zone and said second zone of said pressure vessel to maintain said elevated temperature in said first zone and said cooled temperature in said second zone;wherein said first convective flow and said second convective flow produce a rate of solvent flow through said pressure vessel which is effective to remove said contaminants from said substrate.