Patent ID: 11959702
Assignee: L'AIR LIQUIDE, SOCIETE ANONYME POUR L'ETUDE ET L'EXPLOITATION DES PROCEDES GEORGES CLAUDE
Field: Chemical engineering (Chemistry)
Classification: CPC F  B  Y | IPC B  F

Claim 0:
1. An air separation device comprising:
a first compressor configured to compress a feed air;
a second compressor installed in series or in parallel with the first compressor;
a first refrigerator configured to cool the feed air that has been compressed by the first compressor and/or the second compressor;
a second refrigerator in series or in parallel with the first refrigerator;
a pre-purification unit configured to pre-purify the feed air that has been cooled by the first refrigerator and/or the second refrigerator;
a flow rate measuring unit configured to measure the flow rate of the feed air that has been pre-purified by the pre-purification unit;
a main heat exchanger, into which the feed air that has been pre-purified by the pre-purification unit is introduced for heat exchange;
a purification portion into which the feed air led out from the main heat exchanger is fed, and which separates and purifies product nitrogen and/or product oxygen from the feed air; and
a compressor control unit configured to control the feed quantity of feed air in accordance with an increase or decrease in the production quantity of product nitrogen and/or product oxygen, wherein the compressor control unit comprises:
a pressure setting unit which determines a pressure setting value in accordance with the flow rate of the feed air fed to the purification portion;
a liquid level setting unit which, in accordance with the flow rate of the feed air fed to the purification portion, determines a liquid level setting value for oxygen-enriched liquid collected in the distillation portion; and
a compressor automatic drive unit which automatically starts the standby-side first compressor or second compressor if the flow rate of the feed air is at least equal to a first flow rate threshold, and automatically stops the compressor that is to be put on standby, selected from among the first compressor and the second compressor, if the flow rate of the feed air is at most equal to a second flow rate threshold lower than the first flow rate threshold.