Patent · US Expired

Air separation

US4883517A · kind A · utility

8Cited by
6References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJan 13, 1989
Grant dateNov 28, 1989
Priority date
Expiry dateJan 13, 2009

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S62/924
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

Purified air, typically at its dew point, is introduced into distillation column 10 through inlet 2. Oxygen-rich liquid is withdrawn through outlet 6 and is introduced into the top of a mixing column 20. Nitrogen-rich vapor passes from the top of the distillation column 10 to the bottom of the mixing column 20. In the mixing column, there is a downward flow of liquid that becomes progressively richer in nitrogen and an upward flow of vapor that becomes progressively richer in oxygen. Liquid nitrogen is withdrawn from the mixing column 20 through outlet 28 and is returned to the top of distillation column 10 to provide reflux therefor. In addition, a mixed stream comprising oxygen and nitrogen is withdrawn from the column 20 as product or waste. The mixing column 20 is provided with a first condenser 30 at its top and a second condenser 40 which takes a vapor stream from intermediate the outlet 28 and the top of the column 20 and returns condensed liquid to the column 20. The second condensation is effected by heat exchange with boiling liquid taken from and returned to the column 10. An argon-enriched oxygen stream is withdrawn from the column 10 and is separated in a second distil…

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