SE321246

1,196,473. Refrigerating. INSTITUTE OF GAS TECHNOLOGY. 2 May, 1967, No. 20330/67. Heading F4H. [Also in Division F1] The compressor of a refrigeration system is of the heat-actuated regenerative type comprising an oscillating rotary piston or a reciprocating displacer piston 13 movable in a chamber 1 having disposed therein in series a cooler 7, a regenerator 9 and a heater 11. The working fluid which may be carbon dioxide or sulphur dioxide is admitted at constant pressure from an evaporator through an inlet valve 3 when the working fluid in the chamber 1 occupies the cool part 14 of chamber 1 adjacent the cooler 7 and the hot part 17 of the chamber 1 is almost completely occupied by the piston 13. During the power stroke of the piston 13, working fluid in the cool chamber part 14 is transferred at constant volume through the cooler, regenerator and heater to the hot chamber part 17 and the consequent increase in mean temperature causes the pressure to rise and open an outlet valve 5 leading to a condenser. Thus high pressure working fluid is exhausted at constant pressure. The return stroke of the displacer returns the working fluid at constant volume to the cool chamber part 14 to complete the cycle, which is thereafter repeated. The displacer is driven by an electric or pneumatic motor having sufficient power to overcome the various frictional forces. The cooler is preferably in the form of a finned heat exchanger of copper or aluminium; the regenerator in the form of a matrix of stainless steel wire cloth arranged in layers between corrugated wire mesh; and the heater is in the form of a tube heated from within by a gas burner and surrounded by a radiation shield or wire cloth. A lining 2 covers the chamber 1 and is preferably calcium silicate reinforced with asbestos fibres or calcined diatomaceous silica, bonded with asbestos and coated with a high temperature gas impervious material or fused silica glass foamed to a cellular structure.