GB1305606A - - Google Patents

Abstract

1305606 Refrigerating PHILIPS GLOEILAMPENFABRIEKEN NV 3 March 1970 [6 March 1969] 10143/70 Heading F4H A cold gas refrigerator comprises a first compression space 7 of variable volume in a cylinder 1 which communicates serially with expansion spaces 11, 15 of variable volume via regenerators 9, 13 and freezers 10, 14 respectively. The working medium after throttling in a valve 19 and cooling an object or space 20 is recirculated back to the refrigerator via the low pressure side of a heat exchanger 18 for further compression in a second compression space 28 of variable volume formed in the bore 21 of a displacer 3. A hollow piston-like body 22 is fixed to the upper wall of the expansion space 15 and the common axis of the bore 21 and body 22 coincides or is parallel to the axis of the displacer. The interior of the body 22 communicates with a duct leading. from the throttle valve 19 and through a valve 23 to the compression space 28 which has an outlet incorporating a valve 27 arranged to open when the pressure in the space 28 exceeds the minimum pressure occurring in the refrigerator to allow the working medium to pass via a buffer space 29 to the intermediate expansion space 11 through a non-return valve 31. In a modification, a plurality of intermediate expansion spaces communicating in series through regenerators of decreasing temperatures are provided, and a similar number of further compression spaces are formed in a stepped bore of the displacer, which spaces are serially connected through valved ducts, at least one of these ducts being in heat exchange relationship with an intermediate expansion space.