Air separation unit

Abstract

The present invention provides an air separation device that can reduce the risk of combustion in a heat exchanger connected to an oxygen turbine. Air separation unit A1 includes: a main heat exchanger 1, a medium-pressure distillation column 2, a low-pressure distillation column 4, a crude argon column 5, a nitrogen condenser 3, a crude argon condenser 6, an oxygen turbine 9, an oxygen turbine inlet pipe L32, an oxygen bypass pipe L321, and a dilution flow pipe L42. The oxygen turbine inlet pipe L32 is used to transport oxygen from the bottom of the low-pressure distillation column 4 or the refrigerant storage section of the nitrogen condenser 3 to the oxygen turbine 9 via the main heat exchanger 1, and then back to the main heat exchanger 1. The oxygen bypass pipe L321 branches off from the oxygen turbine inlet pipe L32. The dilution flow pipe L42 is used to discharge nitrogen-containing gas with a lower oxygen concentration than the oxygen discharged from the bottom of the low-pressure distillation column 4 or the refrigerant storage section in the form of a dilution flow, and introduce it into the oxygen turbine inlet pipe L32. none

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