GB1161073A - Refrigerators. - Google Patents

Abstract

1,161,073. Refrigerating. UNION CARBIDE CORP. 19 Aug., 1966 [23 Aug., 19651, No. 37150/66. Heading F4H. The inner wall of a double walled vessel housing cold members of a helium refrigeration circuit is cooled by at least one thermally conducting member which transfers heat from a portion of the wall to the helium circuit or to a container for an externally supplied liquefied gas, which container also cools a portion of the helium circuit. As illustrated, a helium refrigeration system including a compressor 10, expansion engines 16 and 25, and an expansion valve 33 for cooling a load 34a is, apart from the compressor, located within a Dewar vessel the inner wall of which has portions 19 and 27 in heat exchange relation through transverse metal members (175, 179), Fig. 2 (not shown), with portions 18 and 26 of the refrigeration circuit to reduce heat transfer between the wall and the cold end of the circuit and between the warm and cold ends of the circuit. The metal members are slightly spaced from the vessel wall and aid the insertion, removal and location of the circuit in the vessel. The inner vessel is filled with gaseous helium and the evacuated wall space includes glass fibre sheets and aluminium or copper foil. The circuit includes an absorbent bed 28 to remove uncondensed impurities. A surge tank 45 is provided. Preferred operating conditions are disclosed. The expansion engines may be replaced by throttle expansion devices. Cold helium from the expansion valve 33 may be used to cool a load outside the vessel before being returned to the vessel for recirculation.