| 摘要 |
788,173. Liquefaction and revaporization of gases. CONSTOCK LIQUID METHANE CORPORATION. Jan. 31, 1955 [May 10, 1954], No. 2834/55. Class 8(2). Liquefaction of natural gas comprising mostly methane issuing at 2500 p.s.i. and 80‹F. from a well 1, Fig. 4, is effected by preliminary cooling in an exchanger 5 traversed by the gas having been expanded to 1000 p.s.i. at a valve 6 and freed from liquefied higher hydrocarbons which are collected in a separator 8, and then by cooling in an exchanger 12 freeing from carbon dioxide and water vapour in an amine contacter 14 and drier 17 expanding to just below atmospheric pressure and -259‹F. in a turbine 20 and collecting methane so liquefied in a separator 23 ; residual gas being recompressed and after cooled at 28 to 1000 p.s.i., cooled in an exchanger 26 to -95‹F. and added to the gas entering the turbine 20, which, assisted by a steam turbine 31 fed by a boiler 32 fired with some of the recompressed methane, serves to drive the compressor 28. The liquid methane is forced by a pump 35 through a duct 34 to a plurality of metal tanks 36, Fig. 1, loaded on a water-borne vessel 24 powered by an engine 68 running on methane vaporized from the tanks 36 and' stored in a chamber 66. To this end each tank has a balsa wood lining 37, Fig. 3, which conducts sufficient ambient heat to vaporize a portion of the liquid methane and which passes through a duct 49 to the storage chamber 66. Excess gas is vented to atmosphere through a valved port 46, a header 47 and a nozzle 62 of an injector supplied with air from a blower 65. Rapid vaporization of the liquid methane at the destination port is effected by a heating coil 42 and a superheater coil 43 in a closed circuit traversed by a low boiling point liquid forced from a reservoir 54a by a pump 50. The cold so removed from the tanks 36 by the circulating liquid serves to chill brine in a chamber 54 supplied by a pump 58 from a cold storage chamber 56. Blocks of solid carbon-dioxide at the bottom of each tank 36 provides an inert atmosphere during discharge of liquid methane. Reference has been directed by the Comptroller to Specification 766,128. |
