Air separation
US5551258A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 28, 1995 |
| Grant date | Sep 3, 1996 |
| Priority date | — |
| Expiry date | Nov 28, 2015 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25J2250/20
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A stream of air is compressed in compressor and has water vapor and carbon dioxide removed therefrom in purification unit. A part of the resulting purified air is cooled by passage through heat exchanger and is employed to heat an intermediate reboiler in a lower pressure rectification column. The air flow from the reboiler passes into a higher pressure rectification column which supplies a stream of oxygen-enriched liquid air for separation in the lower pressure rectification column. Liquid nitrogen reflux for the higher pressure column is provided by taking nitrogen vapor from this column through an outlet and condensing it in another intermediate reboiler located above the reboiler in the lower pressure rectification column. The condensed nitrogen is returned to the top of the column. Another air stream is employed to reboil a further reboiler at the bottom of the lower pressure rectification column with the resulting condensed air stream being introduced into the higher pressure rectification column through an inlet. An impure oxygen product is withdrawn from the bottom of the lower pressure rectification column through outlet in liquid state and is vaporized in the heat exchan…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.