PROCESS AND APPARATUS FOR PRODUCING OXYGEN HAVING A PURITY OF FROM 90 TO 99.5 PERCENT BY THE RECTIFICATION OF FEED AIR

摘要

D-10882 CRYOGENIC SYSTEM FOR PRODUCING LOW-PURITY OXYGEN Low purity oxygen is produced by fractional distillation of liquefied air in a double distillation column ant an auxiliary distillation column. Feed air is supplied at two different pressures. The disclosed methods of handling intermediate oxygen-enriched liquid produced by the two columns and removing nitrogen-rich gas from the auxiliary distillation column permit the system to operate with lower energy requirements ant smaller column diameter than conventional systems.