Prevention of oil backflow from a screw compressor in a refrigeration chiller
AssigneeAmerican Standard Inc.
InventorDennis M. Beekman
Life of this patent
Estimating the term…
Abstract
A screw compressor in a refrigeration chiller includes one or more baffles disposed in the compressor housing so as to intercept and redirect oil which may flow and/or be blown, under certain operating conditions, in an upstream direction against the stream of suction gas that flows into the compressor from the evaporator. The baffles cause oil to be retained in the compressor rather than being blown back to the system evaporator to ensure that sufficient oil is available to the compressor under all operating conditions and eliminates the need for structure/apparatus in the evaporator dedicated to returning such oil to the compressor.
Claims30
A refrigeration chiller comprising:
- a condenser;
- an expansion device;
- an evaporator;
- a compressor, said compressor, said condenser, said expansion device and said evaporator being serially connected for refrigerant flow and forming a refrigeration circuit, and compressor having a housing, at least one baffle, a working chamber and a location, upstream of said working chamber, where oil tends to collect, said at least one baffle being disposed upstream of said working chamber in said housing and being positioned to prevent the flow of oil out of said housing against refrigerant gas flowing in a downstream flow direction through said housing from said evaporator to said working chamber.
A screw compressor comprising:
- a housing, said housing defining a working chamber, a suction area in which oil tends to collect and a location at which suction gas enters said housing;
- a first screw rotor;
- a second screw rotor, said first and said second screw rotors being disposed in intermeshing relationship in said working chamber, said suction area being defined intermediate said working chamber and said location at which suction gas enters said housing and being a location where oil tends to collect;
- and
- a baffle, said baffle being disposed in said housing, upstream of said working chamber but downstream of said location at which suction gas enters said housing, said baffle being positioned to prevent the backflow of oil from said suction area back to and through said location at which suction gas enters said compressor housing.
A method for preventing the backflow of oil from the compressor in a refrigeration chiller system to the refrigeration system evaporator comprising:
- delivering refrigerant gas from said evaporator to said compressor in a downstream direction;
- flowing said refrigerant gas delivered to said compressor in said delivering step in said downstream direction through said compressor and to a working chamber in said compressor;
- flowing oil to said compressor for use therein, a portion of said oil collecting, after being used, in a location in said compressor which is upstream of said working chamber;
- and
- disposing at least one baffle in said compressor to intercept oil which flows out of said location where oil tends to collect in a direction which is opposite said downstream direction.
Dependencies are inferred from the claim text.