Air separation
US5852940A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1997 |
| Grant date | Dec 29, 1998 |
| Priority date | — |
| Expiry date | Sep 18, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S62/924
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Air is separated in an arrangement of rectification columns comprising a double rectification column (which has a higher pressure column and a lower pressure column), an intermediate pressure rectification column and a side rectification column communicating with the lower pressure column. The side rectification column is provided with a condenser and the intermediate pressure rectification column with a reboiler and a condenser. A stream of oxygen-enriched liquid and a stream of liquid air are withdrawn from the higher pressure column through outlets and are separated in the intermediate pressure rectification column. The reboiler is heated by a stream typically withdrawn from the side rectification column through an outlet. A stream of liquid is withdrawn through an outlet at the bottom of the intermediate pressure rectification column is used to cool the condenser and is separated in the lower pressure rectification column. The mole fraction of oxygen in the stream withdrawn through the outlet is intermediate the oxygen mole fractions in the streams fed to the column via the outlets of the high pressure column.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.