CA2049464A1 - Hot gas defrost system for refrigeration systems and apparatus therefor - Google Patents

Abstract

This invention provides a full flow vaporizer for use in a refrigeration system (which may be part of a heat pump) employing hot gas from the compressor to periodically defrost the cooling coil or coils. The vaporizer usually consists of three concentric circular cross-section tubes, the innermost tube receiving the fluid from the coil and being divided about midway along its length by a disc transverse barrier into first and third chambers. The cylindrical wall of the first chamber is provided with a plurality of holes directing the fluid forcefully radially outwards into a second chamber between the innermost and middle tubes and against the inner wall of the middle tube, which is heated by hot refrigerant gas passing in a fourth chamber between the middle and outermost tubes, the fluid then passing from the second chamber into the third chamber through a similar plurality of holes in the innermost tube cylindrical wall. The first and third chambers and the configuration of the holes leading from them into the second chamber are similar, so that the device is completely reversible and it is immaterial which end of the innermost tube is used as the inlet and which end is used as the outlet. The flow capacities of the passages and the bores are chosen to be in a specific range of flow capacities relative to one another, so that when not in use the vaporizer has no appreciable effect on the remainder of the system.