Combined process to produce liquid helium, liquid nitrogen, and gaseous nitrogen from a crude helium feed
US4659351A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1986 |
| Grant date | Apr 21, 1987 |
| Priority date | — |
| Expiry date | Jan 29, 2006 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25J2260/20
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention is directed to a process for the purification and liquefaction of helium from a feed stream consisting essentially of nitrogen and helium with some minor impurities, wherein the helium is purified in a two step process: the first purification step comprising refrigerating the feed stream to condense nitrogen and any impurities from the feed stream, feeding the cooled feed stream to a separator, and removing from the bottom of the separator the condensed nitrogen and impurities in the feed stream and from the top of the separator a gaseous, high-helium-content stream; the second purification step comprising warming the gaseous, high-helium-content stream from the first purification step, feeding said stream to a pressure swing adsorber, and removing from the pressure swing adsorber an essentially pure helium stream, which is liquefied by feeding said essentially pure helium stream to a liquefier; wherein refrigeration is provided for the warm end of the liquefier and the two step purification; the improvement comprising providing said refrigeration by compressing a side stream of the essentially pure helium in a compressor and expanding said compressed stream i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.