Method and apparatus for gas liquefaction with plural work expansion of feed as refrigerant and air separation cycle embodying the same
US5271231A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 10, 1992 |
| Grant date | Dec 21, 1993 |
| Priority date | — |
| Expiry date | Aug 10, 2012 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25J2290/10
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method of liquefying a low-boiling gas, in which gas is compressed to a high pressure, is cooled in heat exchange structure and is isenthalpically expanded to condense a portion of the same to liquid. The liquid being separated from residual gas and the residual gas is used to cool the heat exchange structure and is then recycled. A portion of the gas is compressed to an intermediate pressure between the high and low pressures, is isentropically expanded at a first temperature and is used to cool a relatively warm portion of heat exchange structure and is then recycled. A portion of the high pressure gas is isentropically expanded at a second temperature and used to cool a relatively cool portion of the heat exchange structure and then again isentropically expanded at a third temperature to that low pressure and returned through the heat exchange structure to cool the same and is then recycled. That first temperature is higher than the second temperature and that second temperature is higher than the third temperature. The gas is preferably nitrogen. The cycle can be part of an air separation unit, whose low pressure nitrogen product is make-up for the liquefaction cycle and whos…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.