Method and apparatus for air separation
US5806341A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 31, 1996 |
| Grant date | Sep 15, 1998 |
| Priority date | — |
| Expiry date | Jul 31, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S62/94
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Air is compressed in an arrangement of compressors. A first flow of the thus compressed air flows through a main heat exchanger from its warm end to its cold end and is liquefied by passage through a valve. Two second stream of compressed air are taken. One is expanded in one expansion turbine and the other in another expansion turbine. The streams leaving the valve and the one expansion turbine are separated in a double rectification column. Liquid oxygen product is extracted from outlet thereof. Part is taken as liquid product and the rest is vaporized by passage through the heat exchanger from its cold end to its warm end and taken as gaseous oxygen product. The ratio of liquid oxygen product to total oxygen product is capable of being varied. Accordingly a chosen but variable proportion of the two second air streams flows to the double rectification column and a chosen but variable proportion of the two second air streams is returned to the arrangement of compressors to an intermediate compressor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.