Abstract: An evaporator including a side plate formed with a number of openings each having rigidly secured therein the upper end portion of one of a number of U-shaped refrigerant tubes, a cover plate attached to the upper surface of the side plate and formed, by recessing its inner surface, with a plurality of bend sections each intercommunicating the upper end portions of the two tubes of the adjacent U-shaped refrigerant tubes forming a set, a distributor section for supplying a suitable refrigerant to refrigerant passages provided by the U-shaped tubes and the bend sections, a manifold section for collecting the refrigerant from the refrigerant passages and discharging same therefrom, and an expansion valve section extending between the distributor section and the manifold section in a manner to intercommunicate the two sections, and an expansion valve assembly mounted in the expansion valve section.

Abstract: An improved change of phase refrigeration system utilizing low compressor head pressures to maximize compressor efficiency, employing a relatively low temperature cooling medium to cool refrigerant gases, using a metering device which is operable at a relatively low pressure differential to feed condensate to the evaporator coil and providing additional controls to temporarily increase head pressure and thus condensate temperature when such increased temperature is needed for heat recovery or gas defrost. Because the proposed refrigeration system employs condensate at a relatively low temperature it may be necessary to enlarge the supply line for liquid refrigerant running from the condenser to the metering device to minimize evaporation of the condensate in the supply line. Further, it may be preferable to insulate the liquid refrigerant line so as to minimize premature evaporation of condensate in that line.