GB1015321A - Improvements in or relating to refrigeration apparatus - Google Patents

Abstract

1,015,321. Refrigeration. L. STERNE & CO. Ltd. Dec. 28, 1961 [Dec. 31, 1960], No. 44901/60. Heading F4H. In refrigeration apparatus including a main condenser 3, an expansion device 7, an auxiliary evaporator 8 and a main evaporator 13 connected in series, the auxiliary evaporator may be caused to function as a condenser while the main evaporator continues to function as an evaporator. The apparatus shown is for use in a refrigerated display cabinet in which the main evaporator is incorporated in the side wall of the cabinet and the auxiliary evaporator is located above the maximum level to which foodstuffs are loaded, air cooled by the auxiliary evaporator being deflected by plates to flow over the foodstuffs stored in the cabinet. In such apparatus, the auxiliary evaporator requires more frequent defrosting than the main evaporator, and such defrosting is effected while the auxiliary evaporator functions as a condenser. During normal operation, refrigerant is passed from a compressor 1 through a water evaporating coil 2, the fan-cooled finned condenser 3, a drier 5, heat exchanger 6, main expansion capillary 7, the evaporator 8, a solenoid valve 9, the evaporator 13, and a liquid refrigerant accumulator 14 and is returned to the compressor via the heat exchanger 6 and a liquid trap 15. For defrosting, the condenser cooling fan is stopped, valve 9 is closed and a valve 16 is opened by a timercontrolled electric circuit (Fig. 2, not shown). The condenser 3 is then by-passed, and refrigerant from the compressor flows direct via a coil 18 and evaporator 8 which both act as condensers), and then via a filter 8 and auxiliary expansion capillary 12 to the evaporator 13. The coil 18 prevents refreezing of the defrosted water dropping from the exterior of evaporator 8.