GB675810A - Improvements in and relating to two-temperature refrigerating systems - Google Patents

Abstract

675,810. Refrigerating. BRITISH THOMSON-HOUSTON CO., Ltd. April 18, 1950 [April 21, 1949], No. 9486/50. Class 29 In a compression refrigerating system comprising a low temperature evaporator 2 and a high temperature evaporator 3 having a common suction trap 11, liquid refrigerant from the capillary tube 6 is fed into a reservoir 7 pivoted on a horizontal axis 17, normally biassed by a spring 21 to the position shown wherein liquid flows by a pipe 9 to the evaporator 2, and provided with a solenoid 23, 24 energized by a thermal bulb 26 so that, upon a predetermined maximum temperature being attained in the evaporator 3, the reservoir is tilted to feed a body of refrigerant to the evaporator 3 by a pipe 10. When vapour is being withdrawn from the evaporator 3, this vapour is prevented from entering the evaporator 2. The pipes 6, 9, 10 include coiled parts 18, 19, 20 to make them flexible and the pipe 9 joins the reservoir at the upper part so that the reservoir stores liquid when in the position shown, this store flooding into the evaporator 3, when tilting occurs, to increase the suction pressure, a check valve 16 being provided to prevent refrigerant vapour entering the evaporator 2. The trap 11 has a partition 15. Instead of the valve 16, the suction conduit from evaporator 2 may enter the bottom of the trap so that a liquid seal forms in this conduit to prevent refrigerant vapour entering the evaporator 2. The compressor is controlled by a thermal bulb 32 responsive to the temperature of evaporator 2.