Patent ID: 6098422
Filing Date: 2000-08-08
Classification: F04D,F25B

Abstract:
A refrigeration chiller comprising:a condenser;a metering device, said metering device receiving refrigerant from said condenser;an evaporator, said evaporator receiving refrigerant from said metering device;a compressor, said compressor receiving refrigerant gas from said evaporator at a first pressure and delivering refrigerant gas at a second, higher pressure to said condenser, said condenser, said metering device, said evaporator and said compressor defining a refrigeration circuit;a low pressure refrigerant, said low pressure refrigerant flowing through said refrigeration circuit when said chiller is in operation;a motor for driving said compressor; anda pump, said pump pumping said low pressure refrigerant, when said refrigerant is in its liquid state, from a location in said refrigeration circuit into contact with said compressor drive motor in order to cool said motor, said pump being a centrifugal pump having a housing, an impeller, and a motor for driving said impeller, said impeller being disposed in said housing, having an inlet portion and having a plurality of vanes, liquid refrigerant received in said inlet portion of said impeller transitioning from flow in an axial direction to flow in a radial direction prior to the interaction of such refrigerant with the leading edges of said plurality of vanes.