GB554807A - Improvements in and relating to refrigerant evaporators - Google Patents

Abstract

554,807. Refrigerating. BRITISH THOMSONHOUSTON CO., Ltd. July 31, 1942, No. 10764. Convention date, Aug. 1, 1941. [Class 29] An evaporator of the type having continuous conduits 22, 23 supplied through a capillary tube 18 or other restricted orifice is provided with a subheader 24 between portions of the conduits to trap liquefied refrigerant therein during idle periods of the compressor, during which liquid may still flow through the capillary tube from the condenser, and as soon as the compressor is started this store of liquid is drawn into a portion of the conduits and evaporates to produce cold immediately. The conduit portion 22 may extend around the edge regions of a V-chaped plate 19 forming a cabinet cooling unit, while the portion 23 forms a sinuous coil within the edge regions. As shown in Fig. 3 the conduit portion 22 discharges into the top of the subheader, and the inlet to the portion 23 is formed as a bent dip extension 34 having an open end 35 in the vapour space, a small orifice 36 in the liquid space, and a pressure-equalizing orifice 37 in the vapour space. Any liquid flowing into the evaporator during idle periods is retained in the subheader and does not reach the compressor. The conduit 23 discharges refrigerant into a suction header 25 in active periods and a conduit 31 in a shelf 28 is maintained flooded with refrigerant by connections 32, 33 with the suction header. As shown in Fig. 4 the main suction pipe 16 may have a bent dip portion 40 in the suction header, between incomplete transverse baffles 38, 39, and lubricant is entrained through an orifice 42 with the vapour suction. A further orifice 43 is provided in the bent pipe above the liquid level.