摘要 |
Air is rectified in a rectification system comprising a higher pressure rectification column, an intermediate pressure rectification column, and a lower pressure rectification column. A first reboiler-condenser provides liquid nitrogen reflux for the higher pressure rectification column and for the lower pressure rectification column and also reboils the intermediate pressure rectification column. Another reboiler-condenser provides liquid nitrogen reflux for the intermediate pressure rectification column and reboils the lower pressure rectification column. Air is fed to the higher pressure rectification column through a pair of inlets. A first oxygen product is withdrawn from the intermediate pressure rectification column by a pump. Gaseous nitrogen products are withdrawn from the intermediate and lower pressure rectification columns through a pair of outlets thereof.
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