Air separation method for use in purification installation, involves separating part of purified air in medium pressure column into oxygen and nitrogen enriched liquids, and sending liquid from column to low pressure column

摘要

The method involves purifying a compressed air flow in an absorption unit with absorbers (R1, R2), and transmitting the air to a column system with low and medium pressure columns (BP, MP). A part of the purified air is separated in the column (MP) into oxygen and nitrogen enriched liquids. Liquid from the column (MP) is sent to the column (BP) after a trigger and during the stage of depressurizing an absorber. A liquid flow sent from the column (MP) to the column (BP) is reduced relative to liquid flow sent to the column (BP) during the stage of absorption or regeneration of the absorber.