Nitrogen production method
US4617037A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1985 |
| Grant date | Oct 14, 1986 |
| Priority date | — |
| Expiry date | Oct 31, 2005 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25J2270/58
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A nitrogen production method wherein air is compressed, is removed of water and carbon dioxide contained therein, and is simultaneously cooled to a temperature close to the liquefying point, and the resultant cleaned and cooled air is fed into a rectifying column for rectification so that high purity nitrogen is withdrawn from the rectifying column overhead; and wherein the oxygen-enriched liquid air withdrawn from the rectifying column bottom is expanded and fed into a condensation step wherein it becomes a source of reflux producing cold in the above-mentioned rectifying column, and then a cold is produced by adiabatically expanding the vaporized gas, after which heat exchange with raw air is performed. In this method, there is provided a closed circulating system wherein a circulating gas which is compressed is cooled by heat exchange with a return gas of the circulating gas, and the resultant cooled gas is fed into a reboiler at the bottom of the above-mentioned rectifying column wherein it vaporizes a liquid in the bottom of the rectifying column, and after the compressed circulating gas itself is liquefied through the above described step and expanded, it is fed into the abov…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.