Air separation
US5657644A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 1996 |
| Grant date | Aug 19, 1997 |
| Priority date | — |
| Expiry date | Mar 20, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S62/924
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A stream of precooled and purified air is introduced into a double rectification column comprising a higher pressure rectification column and a lower pressure rectification column and is separated therein into an oxygen-rich fraction and a nitrogen-rich fraction. A stream of argon-enriched oxygen vapour flows from the lower pressure rectification column into a side column in which argon is separated therefrom. An oxygen-enriched liquid air stream is taken from the bottom of the higher pressure rectification column. A vaporous oxygen-enriched air stream is introduced into the lower pressure rectification column above the point at which argon-enriched oxygen vapour is removed. At least part of the oxygen-enriched liquid is partially reboiled in a reboiler and is separated in a further rectification column, thereby to form a vapour depleted of oxygen and a liquid air stream further enriched in oxygen. At least one stream of the further-enriched liquid is vaporised to form the oxygen-enriched vapour that is introduced into the lower pressure rectification column. A part of the oxygen-depleted vapour is condensed and is taken as product or reintroduced into the lower pressure rectificat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.