摘要 |
Air is compressed in a compressor 2, cooled in a main heat exchanger 6, partially condensed in a reboiler-condenser 12, introduced into a higher pressure rectifier 14, and separated therein into nitrogen and oxygen-enriched liquid. Resulting nitrogen is condensed in further reboiler-condensers 26 and 28. One part of the condensate is used as reflux in the higher pressure rectifier 14 and another part as reflux in a lower pressure rectifier 24. A stream of oxygen-enriched liquid is withdrawn from the rectifier 14 and sent to an intermediate pressure rectifier 30 which is reboiled by the reboiler-condenser 28 and in which further nitrogen is separated. A stream of liquid further enriched in oxygen is withdrawn from the bottom of the intermediate pressure rectifier 30 and is separated in the lower pressure rectifier 24. Impure and pure oxygen products are withdrawn respectively from outlets 88 and 84. In addition an argon-enriched oxygen stream is withdrawn from the lower pressure rectifier 24 through an outlet 92 and separated in an argon rectifier 68. Further impure oxygen product is withdrawn from the bottom of the argon rectifier 68 through an outlet 96. <MATH> |