| 摘要 |
1392302 Liquefying hydrogen and helium BRITISH OXYGEN CO Ltd 23 May 1972 [25 May 1971] 16957/71 Heading F4P In a liquefaction process for hydrogen or helium in which a compressed feed stream is heat exchanged with expanded portions of the feed stream in heat exchanges 14, 16, 18, 20, 22 and then expanded through a Joule-Thompson valve 28 into a collector vessel 30, the expanded vapour therefrom, which provides the cooling for the heat exchanger 22, is passed over one end 34 of a heat pipe 32 whose other end 36 is connected to a point in the system at which the temperature is below the inversion temperature of the gas being liquefied, the heat pipe 32 containing a fluid which freezes above the boiling point of the expanded vapour. For helium liquefaction the fluid is preferably hydrogen and for hydrogen, neon. Expansion of the feed stream portions takes place in turbines 24, 26. Good heat contact between the vapour and the ends of the heat pipe is ensured by baffles, coils or heat exchangers. On starting up the process the heat pipe will transfer heat from end 34 to end 36 to provide a sufficiently cool stream through h.e. 22 so that the gas passing through J.-T. valve 28 is below its inversion temperature. As cooling progresses the vapour from vessel 30 will eventually freeze the fluid in the end 34 of the heat pipe and reduce the loss of heat from that end. |
