Patent ID: 7219514
Filing Date: 2007-05-22
Classification: F25J,Y10S

Abstract:
1. A process for separating air by cryogenic distillation comprising: a) coupling a medium-pressure column and a low-pressure column, wherein said medium-pressure column operates between about 6 and about 9 bar absolute; b) cooling a quantity of compressed and purified air in an exchange line down to a cryogenic temperature, wherein the ratio of the volumetric flow rate of air entering the exchange line to the total volume of the exchange line is between 3000 and 6000 Nm c) sending at least part of the cooled air to the medium-pressure column; d) sending oxygen-enriched and nitrogen-enriched streams from the medium-pressure column to the low-pressure column; and e) withdrawing nitrogen-enriched and oxygen-enriched streams from the low-pressure column.