Method for recovery of pressurized nitrogen product in distilling column system, involves making secondary portion of vaporized/pseudo-vaporized nitrogen flow in indirect heat exchange with oxygen-enriched liquid of high pressure column

摘要

The method involves making high pressure liquid nitrogen flow (850) to a main heat exchanger (20) which vaporizes/pseudo-vaporizes and heats to ambient temperature to obtain a primary portion (853) of nitrogen product. A secondary stream (734) of compacted feed air (801) is set in indirect heat exchange with nitrogen flow and high pressure stream (737) is introduced. A secondary portion (846) of vaporized/pseudo-vaporized nitrogen flow is set in indirect heat exchange with oxygen-enriched liquid (462) in sump vaporizer (9) of high pressure column (8). An independent claim is included for device for recovery of pressurized nitrogen product by low temperature separation of air in distilling column system for nitrogen-oxygen separation.