Patent ID: 6357259
Filing Date: 2002-03-19
Classification: F25J,Y10S

Abstract:
A method of separating air to produce a gaseous product, enriched in a component of the air and in accordance with a demand cycle having high and low periods of demand, said method comprising:producing first and second liquid streams by cryogenic rectification of the air, the first liquid stream being enriched in said component of the air; during the low period of demand, forming a supply of stored product from said first liquid stream; during the high period of demand, pressurizing a first product stream formed from at least part of the stored liquid product, vaporizing said product stream to produce said gaseous product, and condensing a first further compressed air stream passing in indirect heat exchange with said product stream; and during at least the low period of demand, producing refrigeration by expanding a second further compressed air stream with performance of work, thereby to refrigerate said low temperature rectification process and to permit production of said first and second liquid stream and also, to produce a liquid product composed of said second liquid stream; whereby an air flow rate of the air to be further compressed during the low period of demand is greater than that otherwise required had said liquid product not been produced.