Refrigerant Pumps Patents (Class 62/DIG2)
  • Patent number: 6145332
    Abstract: Apparatus for protecting a liquid refrigerant pump from damage due to cavitation and loss of lubrication by inclusion of means for detecting the presence of vaporized refrigerant at the pump inlet and deactivating the pump in response thereto.
    Type: Grant
    Filed: June 16, 1999
    Date of Patent: November 14, 2000
    Assignee: DTE Energy Technologies, Inc.
    Inventor: Robert E. Hyde
  • Patent number: 5974812
    Abstract: A vapor compression system having a compressor, condenser, receiver, evaporator, two liquid refrigerant tanks, a phase separator and a liquid refrigerant heat exchanger. The liquid refrigerant is pumped alternatively from one of the tanks through the heat exchanger using controlled valving such that there is no phase change and gaseous refrigerant is withdrawn by the compressor from the top of the phase separator.
    Type: Grant
    Filed: January 21, 1998
    Date of Patent: November 2, 1999
    Inventors: Lajos Katai, Lajos Katai, Jr., Zoltan Katai
  • Patent number: 5913664
    Abstract: A safety relief valve assembly for use in a fluid displacement apparatus of an automotive air conditioning system includes a valve mechanism which releases gas when the pressure in the fluid displacement apparatus increases above a predetermined pressure level. A control device is detachably mounted on the valve mechanism to direct the flow of the gas in a predetermined direction. An elastic member is forcibly disposed between the valve mechanism and the control device. The elastic member has a groove facing the valve mechanism. The groove and the valve mechanism collectively form a passage for directing excessively pressurized gas away from the hot components in the vehicle engine compartment.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: June 22, 1999
    Assignee: Sanden Corporation
    Inventors: Hidehiko Shimizu, Masashi Yaguchi
  • Patent number: 5749237
    Abstract: The invention entails the use of a positive displacement pump (4) magnetically coupled to an drive motor (42) located in a conduit arrangement (60) this is parallel to the liquid line of the refrigeration system as in FIG. 5. This parallel conduit arrangement also includes a pressure regulating valve that will regulate the amount of pressure added to the liquid line by the parallel pump and piping arrangement. In addition, a check valve (47) is located in the liquid line to maintain the pressure differential added to the liquid line. This parallel piping arrangement (60) is desirable in order to allow a constant, pre-determined pressure to be added to the liquid line regardless of variations in flow rate of the liquid refrigerant. In addition, the parallel piping arrangement allows the system to operate without liquid line obstruction in the event of pump failure.
    Type: Grant
    Filed: October 26, 1995
    Date of Patent: May 12, 1998
    Assignee: JDM, Ltd.
    Inventors: Marc D. Sandofsky, David F. Ward
  • Patent number: 5694780
    Abstract: A refrigeration system which has in a closed loop a compressor body, with a cooling jacket, for compressing a refrigerant, a condenser for condensing the compressed refrigerant to a liquid refrigerant, and a condensed liquid pump for compressor body cooling. The compressor body is thermally coupled to a cooling jacket, through which a cooling liquid flows. The condensed liquid pump pumps condensed liquid refrigerant from the condenser through the cooling jacket, cooling the compressor body, and then to the compressor cylinder head exhaust manifold, where the liquid refrigerant mixes with and cools the hot compressor discharge gas.
    Type: Grant
    Filed: December 1, 1995
    Date of Patent: December 9, 1997
    Inventor: Richard H. Alsenz
  • Patent number: 5692387
    Abstract: A refrigeration system includes in a closed loop connection a compressor for compressing a refrigerant, a desuperheater for cooling the hot compressor discharge gas via the injection of liquid refrigerant, and a condenser for condensing the compressed, desuperheated refrigerant into a liquid refrigerant. The liquid refrigerant is injected into the compressed refrigerant by utilizing a liquid column for supplying pressure to the liquid refrigerant for injecting liquid refrigerant into the compressed refrigerant without using a mechanical pump. Another method of injecting the liquid refrigerant into the compressed refrigerant is to use a venturi pump at the injection point to supply the liquid refrigerant for injection into the compressed refrigerant. The desuperheater causes the temperature of the hot refrigerant vapor leaving the compressor to be reduced from a superheated condition to temperature closer to its condensing temperature prior to its entry to the condenser.
    Type: Grant
    Filed: April 28, 1995
    Date of Patent: December 2, 1997
    Assignee: Altech Controls Corporation
    Inventors: Richard H. Alsenz, Timothy G. Burns, Bryan J. Rees
  • Patent number: 5678626
    Abstract: A vapor compression air conditioning (cooling and heating) system adapted for operation to reduce the consumption of electric power during peak periods of demand for power is characterized by four refrigerant circuits. A first circuit includes a compressor, a first heat exchanger and a second heat exchanger. A second circuit comprises the compressor, the first heat exchanger and a third heat exchanger. A third circuit comprises the third heat exchanger, a refrigerant pump and a thermal energy storage unit characterized by a tank having a thermal energy storage medium disposed therein. A fourth circuit includes the thermal energy storage unit, the refrigerant pump and a fourth heat exchanger. The first heat exchanger is an outdoor heat exchanger. The second and fourth heat exchangers are indoor heat exchangers in heat transfer relationship with the fluid (e.g., indoor supply air) to be cooled or heated.
    Type: Grant
    Filed: November 17, 1995
    Date of Patent: October 21, 1997
    Assignee: Lennox Industries Inc.
    Inventor: Theodore C. Gilles
  • Patent number: 5666814
    Abstract: The heat transfer system of the present invention transfers heat from above to below by means of phase change of an operating fluid without applying power from outside, and it facilitates to keep balance between evaporation quantity of the operating fluid by an evaporator and return quantity of the operating fluid from a condenser to the evaporator by a heat driving pump, and to improve heat transfer efficiency, heat transfer distance and heat transfer quantity. For this purpose, the condenser 2 is provided at a position lower than the evaporator 1, and the heat driving pump 3 is installed along a flow passage to send the operating fluid 9 from the condenser 2 to the evaporator 1. In the heat driving pump 3, air bubbles generated by heating of the high temperature fluid are condensed by cooling with the low temperature fluid, and by pressure change generated, the operating fluid 9 is sent back from the condenser 2 to the evaporator 9.
    Type: Grant
    Filed: December 16, 1994
    Date of Patent: September 16, 1997
    Assignee: Agency of Industrial Science and Technology
    Inventor: Tadashi Yamamoto
  • Patent number: 5664425
    Abstract: A reheater is used in air-conditioning system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed loop. A first conduit coupling a flow of liquid refrigerant through the expansion valve into the evaporator. A second conduit coupling an outlet of the evaporator to an inlet of the compressor. A third conduit coupling an outlet of the compressor to an inlet of the condenser. A centrifugal pump is coupled to an outlet of the condenser for boosting a pressure of the condensed liquid refrigerant by an incremental pressure sufficient to pressure subcool the refrigerant.
    Type: Grant
    Filed: February 6, 1996
    Date of Patent: September 9, 1997
    Inventor: Robert E. Hyde
  • Patent number: 5626025
    Abstract: Liquid pressure amplification with Bypass is used in an air-conditioning or refrigeration system which includes a compressor, a condenser, a pump, an expansion valve, and an evaporator, interconnected by conduits in a closed refrigerant loop. A first conduit coupling an outlet of the compressor to an inlet to the condenser. A centrifugal pump is coupled to the condenser (or receiver) outlet for boosting the pressure of the condensed liquid refrigerant by a substantially constant increment. A second conduit transmits a first portion of the condensed liquid refrigerant from outlet of the pump through the expansion valve into the evaporator to effect cooling. A third conduit transmits a second portion of the condensed liquid refrigerant from the pump outlet into the condenser inlet, which cools the superheated vapor refrigerant entering the condenser, reducing head pressure.
    Type: Grant
    Filed: March 15, 1994
    Date of Patent: May 6, 1997
    Inventor: Robert E. Hyde
  • Patent number: 5544496
    Abstract: A refrigeration system is disclosed in which negative energy storage is provided to significantly reduce electrical energy consumption during peak air conditioning hours. A transfer pump is provided in the system for pumping condensed and mixed phase refrigerant from the negative energy storage to an evaporator coil where it absorbs heat energy from an air conditioned space. The transfer pump is a positive displacement pump employing a rotor and vanes rotating in a pumping chamber. Dual inlets and discharges from the pumping chamber are located to balance forces on the rotor. The inlets enter the pumping chamber radially. A hermetic enclosure seals the pump and an electric drive motor to eliminate dynamic seals within the pump and thereby greatly reduce leakage of refrigeration from the system. A refrigeration overfeed system using a hermetically sealed pump according to the invention is also disclosed.
    Type: Grant
    Filed: July 15, 1994
    Date of Patent: August 13, 1996
    Assignee: Delaware Capital Formation, Inc.
    Inventors: Thomas D. Stoll, Lawrence E. Switek
  • Patent number: 5537835
    Abstract: A system for transferring a refrigerant from a first refrigerant vessel having at least one refrigerant port to a second refrigerant vessel having at least one refrigerant port is disclosed. This system includes a condenser, a pump assembly having an inlet and an outlet, and conduits for operatively connecting the condenser and pump assembly to the first and second refrigerant vessel in several configurations. The pump assembly includes two pumps operated by one motor and interconnected to either provide series or parallel pumping. This system may also include a transfer tank interposed between the first and second refrigerant vessels. The transfer tank can be used to condense the vapor phase of the refrigerant removed from the first refrigerant vessel and collect the condensed refrigerant in one configuration, then to transfer the condensed refrigerant to the second refrigerant vessel in an alternate configuration.
    Type: Grant
    Filed: September 28, 1995
    Date of Patent: July 23, 1996
    Assignee: American Standard Inc.
    Inventor: Robert J. Roth
  • Patent number: 5533345
    Abstract: A system for transferring a refrigerant from a first refrigerant vessel having at least one refrigerant port to a second refrigerant vessel having at least one refrigerant port is disclosed. This system includes a condenser, a pump assembly having an inlet and an outlet, and conduits for operatively connecting the condenser and pump assembly to the first and second refrigerant vessel in several configurations. The pump assembly includes two pumps operated by one motor and interconnected to either provide series or parallel pumping. This system may also include a transfer tank interposed between the first and second refrigerant vessels. The transfer tank can be used to condense the vapor phase of the refrigerant removed from the first refrigerant vessel and collect the condensed refrigerant in one configuration, then to transfer the condensed refrigerant to the second refrigerant vessel in an alternate configuration.
    Type: Grant
    Filed: August 12, 1994
    Date of Patent: July 9, 1996
    Assignee: American Standard Inc.
    Inventor: Robert J. Roth
  • Patent number: 5509272
    Abstract: A reheater is used in air-conditioning system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed loop. A first conduit coupling a flow of liquid refrigerant through the expansion valve into the evaporator. A second conduit coupling the an outlet of the evaporator to an inlet of the compressor. A third conduit coupling an outlet of the compressor to an inlet of the condenser. A centrifugal pump is coupled to an outlet of the condenser for boosting a pressure of the condensed liquid refrigerant by an incremental pressure sufficient to pressure subcool the refrigerant.
    Type: Grant
    Filed: July 18, 1994
    Date of Patent: April 23, 1996
    Inventor: Robert E. Hyde
  • Patent number: 5467812
    Abstract: A vapor compression air conditioning (cooling and heating) system adapted for operation to reduce the consumption of electric power during peak periods of demand for power is characterized by three refrigerant circuits. A refrigerant circuit includes a compressor, outdoor heat exchanger and first indoor heat exchanger for selectively cooling or heating an indoor air space and a second refrigerant circuit comprises the compressor, outdoor heat exchanger and a thermal energy storage unit characterized by a tank having a thermal energy storage medium disposed therein and a heat exchanger coil in communication with the compressor and outdoor heat exchanger for cooling the thermal energy storage medium. A third refrigerant circuit includes the thermal energy storage heat exchanger coil, a refrigerant pump and another indoor heat exchanger in communication with the fluid (e.g., indoor air) to be cooled or heated.
    Type: Grant
    Filed: August 19, 1994
    Date of Patent: November 21, 1995
    Assignee: Lennox Industries Inc.
    Inventors: William J. Dean, Theodore C. Gilles
  • Patent number: 5457964
    Abstract: This invention is a low pressure refrigeration or air-conditioning system comprising a compressor, a condenser and an evaporator interconnected in series in a closed loop for circulating refrigerant therethrough, and an improved subcircuit including a subcooler and centrifugal pump connected in series to recycle a portion of the liquid refrigerant from the condenser outlet back to the condenser inlet to desuperheat compressed refrigerant vapors. The subcooler receives a portion of the condensed liquid refrigerant from the outlet of the condenser at condenser outlet temperature and lowers that temperature by an increment of temperature, typically about 2.degree.-3.degree. F., to a temperature sufficiently lower than the condenser outlet temperature to prevent flashing of the refrigerant in the pump intake.
    Type: Grant
    Filed: May 24, 1994
    Date of Patent: October 17, 1995
    Inventor: Robert E. Hyde
  • Patent number: 5435148
    Abstract: A compression-type refrigeration system is disclosed, in which "flash gas" formation is eliminated without artificially maintaining condenser temperature and pressure levels. Condenser temperatures and pressures are allowed to fluctuate with ambient operating conditions, resulting in reduced compressor load and increased refrigeration capacity. After condensation, liquified refrigerant in the conduit between the receiver and the expansion valve is pressurized without adding heat, by means of a combination of (a) a positive-displacement pump, in parallel with the conduit, (b) a bypass conduit pressure regulating controller, and (c) a check valve in the conduit, to a pressure sufficient to suppress flash gas in the conduit. A variable speed liquid injection pump is provided to inject liquid refrigerant from downstream of the positive-displacement pump to upstream of the condenser, at a controlled rate sufficient to desuperheat the refrigerant upstream of the condenser.
    Type: Grant
    Filed: September 28, 1993
    Date of Patent: July 25, 1995
    Assignee: JDM, Ltd.
    Inventors: Marc D. Sandofsky, David F. Ward
  • Patent number: 5435152
    Abstract: An air treating device having a bellows box in which is mounted a bellows compressor formed of two spaced apart diaphragms having memory-shaped metal alloy elements embedded therein. The diaphragms are caused to contract and expand by selective heating of the memory-shaped metal alloy elements. The bellows compressor is supported spaced in the bellows box whereby air can flow through the box and as the bellows expand the air in the box is cooled and expelled. As the diaphragms of the bellows compressor contract, more air is sucked into the bellows box and at the same time the refrigerant fluid inside the bellows is expelled into a condenser where it is condensed to liquid. When the refrigerant liquid enters into the bellows it is vaporized and cools the bellows walls in their expanded state and the diaphragms act as a heat exchanger to cool air in said bellows box and expel it therefrom.
    Type: Grant
    Filed: February 18, 1994
    Date of Patent: July 25, 1995
    Assignee: Microcool Corporation
    Inventor: Robert McCausland
  • Patent number: 5400615
    Abstract: A refrigeration apparatus comprises a primary refrigeration circuit of the vapour compression type. Cooling is then provided at desired locations remote from the primary circuit using a secondary circuit containing carbon dioxide as a volatile secondary heat transfer substance. The carbon dioxide is liquified in secondary condenser (cooled by primary evaporator) and is circulated by circulation pump to expansion valves and cooling units at desired locations where it evaporates and provides cooling. The volume of possibly environmentally harmful refrigerant employed in the vapour compression primary circuit is minimized.
    Type: Grant
    Filed: July 23, 1992
    Date of Patent: March 28, 1995
    Assignee: Thornliebank Industrial Estate
    Inventor: Stephen F. Pearson
  • Patent number: 5386700
    Abstract: Liquid pressure amplification with superheat suppression is used in an air-conditioning or refrigeration system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed refrigerant loop. A first conduit coupling an outlet of the compressor to an inlet to the condenser. A centrifugal pump is coupled to the condenser (or receiver) outlet for boosting the pressure of the condensed liquid refrigerant by a substantially constant increment. A second conduit transmits a first portion of the condensed liquid refrigerant from outlet of the pump through the expansion valve into the evaporator to effect cooling. A third conduit transmits a second portion of the condensed liquid refrigerant from the pump outlet into the condenser inlet, which cools the superheated vapor refrigerant entering the condenser, reducing head pressure.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: February 7, 1995
    Inventor: Robert E. Hyde
  • Patent number: 5385033
    Abstract: A compression-type refrigeration system is disclosed, in which "flash gas" formation is eliminated without artificially maintaining condenser temperature and pressure levels. Condenser temperatures and pressures are allowed to fluctuate with ambient operating conditions, resulting in reduced compressor load and increased refrigeration capacity. After condensation, liquified refrigerant in the conduit between the receiver and the expansion valve is pressurized without adding heat, by means of a combination of (a) a positive-displacement pump, in parallel with the conduit, (b) a bypass conduit pressure regulating controller, and (c) a check valve in the conduit, to a pressure sufficient to suppress flash gas in the conduit. A variable speed liquid injection pump is provided to inject liquid refrigerant from downstream of the positive-displacement pump to upstream of the condenser, at a controlled rate sufficient to desuperheat the refrigerant upstream of the condenser.
    Type: Grant
    Filed: September 28, 1993
    Date of Patent: January 31, 1995
    Assignee: JDM, Ltd.
    Inventors: Marc D. Sandofsky, David F. Ward
  • Patent number: 5341649
    Abstract: Method and apparatus for remotely monitoring the condition of a heat transfer fluid in the liquid line of a heat transfer system. The operation of the system is controlled in response to the results of the remote monitoring which may be used to indicate excessive moisture in the heat transfer fluid, low levels of heat transfer fluid, and non-condensed transfer fluid in the liquid line. Based upon the monitoring of the transfer fluid for non-condensed fluid, the rate of movement of a cooling fluid past a condenser for the transfer fluid is varied so that the temperature of the heat transfer fluid is kept as low as possible without formation of bubbles of non-condensed transfer fluid in the liquid line.
    Type: Grant
    Filed: March 5, 1993
    Date of Patent: August 30, 1994
    Assignee: Future Controls, Inc.
    Inventors: James N. Nevitt, Laurel R. Chapman
  • Patent number: 5329782
    Abstract: A reheater is used in air-conditioning system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed loop. A first conduit coupling a flow of liquid refrigerant through the expansion valve into the evaporator. A second conduit coupling the an outlet of the evaporator to an inlet of the compressor. A third conduit coupling an outlet of the compressor to an inlet of the condenser. A centrifugal pump, coupled to an outlet of the condenser, for boosting a pressure of the condensed liquid refrigerant by an incremental pressure sufficient to pressure subcool the refrigerant.
    Type: Grant
    Filed: October 12, 1993
    Date of Patent: July 19, 1994
    Inventor: Robert E. Hyde
  • Patent number: 5291744
    Abstract: Liquid pressure amplification with superheat suppression is used in an air-conditioning or refrigeration system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed refrigerant loop. A first conduit coupling an outlet of the compressor to an inlet to the condenser. A centrifugal pump is coupled to the condenser (or receiver) outlet for boosting the pressure of the condensed liquid refrigerant by a substantially constant increment. A second conduit transmits a first portion of the condensed liquid refrigerant from outlet of the pump through the expansion valve into the evaporator to effect cooling. A third conduit transmits a second portion of the condensed liquid refrigerant from the pump outlet into the condenser inlet, which cools the superheated vapor refrigerant entering the condenser, reducing head pressure.
    Type: Grant
    Filed: September 21, 1992
    Date of Patent: March 8, 1994
    Inventor: Robert E. Hyde
  • Patent number: 5239835
    Abstract: The present inventions are intended to improve heat efficiency of a refrigeration system having plural refrigerating cycles of different evaporating or condensing temperatures typically used in breweries. Each of main lines of different evaporating temperatures are connected with each of suction lines to a compressor respectively, to enable the system to save energy and to establish a back-up system of compressors. A different condensing temperature system having a common refrigerant source is provided with refrigerant transferring means to transfer refrigerant from an refrigerant excess cycle to an refrigerant insufficiency cycle.
    Type: Grant
    Filed: April 21, 1992
    Date of Patent: August 31, 1993
    Assignees: Asahi Breweries, Ltd., Mayekawa Mfg. Co., Ltd.
    Inventors: Masaru Kitaguchi, Shigeru Sakashita
  • Patent number: 5174130
    Abstract: A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.
    Type: Grant
    Filed: March 14, 1990
    Date of Patent: December 29, 1992
    Assignee: Sonic Compressor Systems, Inc.
    Inventor: Timothy S. Lucas
  • Patent number: 5150580
    Abstract: Liquid pressure amplification with superheat suppression is used in an air-conditioning or refrigeration system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed refrigerant loop. A first conduit coupling an outlet of the compressor to an inlet to the condenser. A centrifugal pump is coupled to the condenser (or receiver) outlet for boosting the pressure of the condensed liquid refrigerant by a substantially constant increment. A second conduit transmits a first portion of the condensed liquid refrigerant from outlet of the pump through the expansion valve into the evaporator to effect cooling. A third conduit transmits a second portion of the condensed liquid refrigerant from the pump outlet into the condenser inlet, which cools the superheated vapor refrigerant entering the condenser, reducing head pressure.
    Type: Grant
    Filed: March 8, 1991
    Date of Patent: September 29, 1992
    Inventor: Robert E. Hyde
  • Patent number: 5088292
    Abstract: A refrigeration system (10) having a compressor rotor (20) rotatably supported by a plurality of hydrodynamic bearings (22 and 24) lubricated by oiless pressurized liquid refrigerant supplied to a refrigerant circuit (36) coupled to the hydrodynamic bearings at least in part from the compressor rotor and pressurizing refrigerant which flows to a condenser (34) providing liquid refrigerant which flows to an evaporator (68) in fluid communication with the condenser includes a bearing pump (26), coupled to the refrigerant circuit and to the condenser, for providing pressurized refrigerant to the refrigerant circuit at a pressure higher than a pressure of the refrigerant provided by the compressor rotor when the bearing pump is operating; and a controller (28) for activating the bearing pump in accordance at least one the predetermined conditions of operation of the refrigeration system.
    Type: Grant
    Filed: July 10, 1990
    Date of Patent: February 18, 1992
    Assignee: Sundstrand Corporation
    Inventors: John M. Champagne, Peter D. Waters
  • Patent number: 5086828
    Abstract: An apparatus for rejecting waste heat from a system located on or near the lunar equator which utilizes a reflective catenary shaped trough deployed about a vertical radiator to shade the radiator from heat (i.e., infrared radiation) emitted by the hot lunar surface. The catenary shaped trough is constructed from a film material and is aligned relative to the sun so that incoming solar energy is focused to a line just above the vertical radiator and thereby isolate the radiator from the effects of direct sunlight.The film is in a collapsed position between side by side support rods, all of which are in a transport case. To deploy the film and support rods, a set of parallel tracks running perpendicular to length of the support rods are extended out from the transport case.
    Type: Grant
    Filed: September 25, 1991
    Date of Patent: February 11, 1992
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Michael K. Ewert
  • Patent number: 5050389
    Abstract: A refrigeration system (10) having a compressor rotor (20) rotatably supported by a plurality of hydrodynamic bearings (22 and 24) lubricated by oiless pressurized liquid refrigerant and pressurizing refrigerant which flows to a condenser (34) providing liquid refrigerant which flows to an evaporator (68) in fluid communication with the condenser and the compressor in accordance with the invention includes a refrigeration circuit (36) coupled to the compressor, for providing pressurized refrigerant to the hydrodynamic bearings from the compressor and to the evaporator; a bearing pump (26), coupled to the refrigerant circuit and to the condenser, for providing pressurized refrigerant to the refrigeration circuit; a first temperature sensor (101) sensing a temperature Tsink of a heat exchange fluid at the condenser and providing a temperature signal representative of the temperature Tsink of the heat exchange fluid at the condenser; a second heat exchange sensor (103) sensing a temperature Tsource of a heat exc
    Type: Grant
    Filed: July 10, 1990
    Date of Patent: September 24, 1991
    Assignee: Sundstrand Corporation
    Inventors: David B. Wigmore, John C. Lentz, Edward S. Blain, Peter D. Waters
  • Patent number: 4599873
    Abstract: A compression-type refrigeration system is disclosed, in which "flash gas" formation is eliminated without artificially maintaining condenser temperature and pressure levels. Condenser temperatures and pressures are allowed to fluctuate with ambient operating conditions, resulting in reduced compressor load and increased refrigeration capacity. After condensation, liquified refrigerant in the conduit between the receiver and the expansion valve is pressurized without adding heat by a centrifugal pump to a pressure sufficient to suppress flash gas in the conduit.
    Type: Grant
    Filed: January 31, 1984
    Date of Patent: July 15, 1986
    Inventor: Robert E. Hyde
  • Patent number: 4419865
    Abstract: The invention relates to improvements in a refrigeration system having an oil cooled screw compressor from which mixed oil and compressed refrigerant issues to an oil separator via a discharge duct, and wherein a refrigerant pump draws liquid refrigerant from the high pressure receiver and delivers it to the discharge duct to cool the oil and desuperheat the refrigerant. The refrigerant pump and a hydraulic motor that drives it are in a single sealed housing. The hydraulic motor is energized with pressure oil from the oil pump whereby oil is returned to the compressor from the oil separator. Oil flow to the hydraulic motor is throttled in accordance with output from a temperature sensor at the discharge duct, to maintain a constant temperature of oil-refrigerant mixture passing to the oil separator. A standpipe arrangement prevents cavitation at the refrigerant pump.
    Type: Grant
    Filed: December 31, 1981
    Date of Patent: December 13, 1983
    Assignee: Vilter Manufacturing Company
    Inventor: Paul G. Szymaszek
  • Patent number: 4123919
    Abstract: A refrigeration feed system includes an accumulator adapted to contain liquid in its lower portion and to contain gas in its upper portion. A plurality of individual evaporators are arranged each at a different elevation above the accumulator. A pump withdraws liquid from the lower portion of the accumulator and pumps the liquid through a supply manifold to each one of the evaporators. There is a return manifold from each of the evaporators to the upper portion of the accumulator. Each evaporator has an upgoing pipe coming from the supply manifold and has a downgoing pipe going to the return manifold. A connecting device between the upgoing and downgoing pipes forms a weir disposed substantially at the elevation of the upper portion of the respective evaporator to which the manifold is connected. Liquid rising in the upgoing pipe can overflow into and mix with gas in the downgoing pipe and continue by gravital drainage back to the accumulator for recirculation.
    Type: Grant
    Filed: July 25, 1977
    Date of Patent: November 7, 1978
    Assignee: NPI Corporation
    Inventor: Gustav James Fehlhaber