Air separation apparatus for nitrogen production, has exchange line including dephlegmation and heat exchanger sections, where dephlegmation section is connected to column and oxygen enriched liquid pipe

摘要

The apparatus has a pipe (1) sending compressed and purified air to an exchange line (3). Another pipe sends compressed, purified and cooled air from the exchange line to a simple distillation column (7). A pipe (11) withdraws oxygen enriched liquid from the column and sends the liquid to the exchange line. The exchange line includes a dephlegmation section (3B) and a heat exchanger section (3A), where the dephlegmation section is connected to the column and the oxygen enriched liquid pipe and the heat exchanger section is connected to the cooled air pipe and the dephlegmation section. An independent claim is also included for a method of separating air.