Abstract: A refrigeration chiller makes use of the flow of oil from an oil sump location to the chiller's compressor to power an eductor to return oil which has made its way to the evaporator of the chiller system from the evaporator to the compressor.

Abstract: Compressor lubricant in a screw compressor-based refrigeration system is cooled by directing the lubricant from the system oil separator to an oil-cooling heat exchanger disposed in the lower portion of the system condenser where it is bathed in condensed system refrigerant. Parasitic capacity losses with respect to the compressor lubricant cooling process are thereby avoided.

Abstract: An oil separator for a refrigeration system employing a screw compressor includes a generally cylindrical, vertically upstanding housing the bottom of which defines an oil sump and the top of which is penetrated by discharge conduit connecting the oil separator to the refrigeration system condenser. The center line of the discharge conduit is parallel to but offset from the center line of the separator housing so that the discharge conduit is non-concentric with the housing. As a result, an enlarged tangential inlet to the interior of the separator is made possible which is unimpeded by the discharge conduit. The cross sectional flow area through which the mixture discharged from the compressor passes prior to entering the separator can therefore likewise be increased. As a result, pressure drop in the refrigerant gas as a result of the oil separation process is reduced and overall system efficiency is enhanced while the diameter of the separator housing is minimized.

Abstract: Compressor lubricant in a screw compressor-based refrigeration system is cooled by directing the lubricant from the system oil separator to an oil-cooling heat exchanger disposed in the lower portion of the system condenser where it is bathed in condensed system refrigerant. Parasitic capacity losses with respect to the compressor lubricant cooling process are thereby avoided.