Patent ID: 6536059
Filing Date: 2003-03-25
Classification: B08B,D06F

Abstract:
A method for pumpless transfer of liquid carbon dioxide cleaning medium in a carbon dioxide dry cleaning apparatus having a wash vessel, a working vessel, a vapor vessel, and a compressor, said method comprising the steps of:(a) storing liquid carbon dioxide dry cleaning medium in said working vessel; (b) storing a vapor comprising air and carbon dioxide as a gas under pressure in said vapor vessel; (c) transferring a portion of said vapor from said vapor vessel to said wash vessel, by at least partially equilibrating the pressure between said vapor vessel and said wash vessel, with said wash vessel remaining at a pressure less then that of said working vessel; then (d) transferring at least a portion of said liquid carbon dioxide cleaning medium from said working vessel to said wash vessel by the force of a pressure differential therebetween; (e) washing articles to be cleaned in said wash vessel while concurrently (f) circulating at least a portion of said liquid dry cleaning medium (i) from said wash vessel to said working vessel by compressing vapor from said working vessel into said wash vessel with said compressor, and then (ii) from said working vessel back to said wash vessel by compressing vapor from said wash vessel into said working vessel with said compressor.