Air separation
US5533339A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 1995 |
| Grant date | Jul 9, 1996 |
| Priority date | — |
| Expiry date | May 22, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S62/924
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Air is compressed in compressors, cooled in a main heat exchanger, and separated into oxygen and nitrogen products in a double rectification column comprising a higher pressure rectification column and a lower pressure rectification column. A liquid oxygen product is withdrawn from the lower pressure column via a conduit. A liquid nitrogen product is also formed. An argon-enriched oxygen vapour stream is withdrawn from the lower pressure column through an outlet and has argon separated from it in an argon column. In order to help meet the requirements of the higher pressure column for reflux, a nitrogen vapour stream is withdrawn from the top of the lower pressure column, is warmed by passage through the heat exchanger, is recompressed in a compressor, and is liquefied by passage back through the heat exchanger from its warm end to its cold end and passage through a valve. A high liquid make and a high argon recovery can both be achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.