| 摘要 |
1,096,697. Natural gas liquefaction process. INTERNATIONAL RESEARCH & DEVELOPMENT CO. Ltd. Sept. 27, 1966, No. 43031/66. Heading F4P. Natural gas is liquefied by compressing it at 2 to a high pressure, e.g. 200 ats., cooling in a heat exchanger 5 to its liquefaction temperature, expanding at a turbine 7 to an intermediate pressure, e.g. 20 ats., further cooling in a heat exchanger 9, flashing at valve 10 into a vessel 11 at a low pressure, e.g. 1À5 ats., withdrawing product liquid gas through a line 12 and recirculating the flash gas in a separate circuit to effect cooling of the feed in heat exchangers 5, 9. The flash gas leaving the warm end of exchanger 5 is compressed to 200 ats. at 16, 18, expanded to 20 ats. at a turbine 20 and a first portion of the cooled expanded flash gas is returned through a line 25 and exchanger 5 to the inlet of compressor 18, a second portion is cooled in a heat exchanger 14 and added at 28 to the liquid feed leaving turbine 7 at the same pressure, whilst the remainder of the flash gas is expanded to 1À5 ats. at 22 and returned to vessel 11. |
