Abstract: A method and apparatus for monitoring oil charge loss for use with a refrigeration system. The refrigeration system has a compressor for compressing a refrigerant gas, an oil/gas separator for separating compressed refrigerant from lubricating oil, a condenser for condensing the compressed refrigerant gas, an oil cooler for cooling oil separated from the refrigerant, the refrigerant and oil both having known and differing coefficients of heat transfer, and an injection system for injecting the cooled oil into the compressor.

Abstract: A horizontal-installation-type scroll compressor requiring small installation space adopts a technique which can reduce the amount of refrigerating machine oil circulating through the refrigeration cycle. By using this scroll compressor, an air conditioner is provided whose unit body has a reduced depth and which has satisfactory ventilation efficiency and cyclic efficiency.The scroll compressor includes a closed container which is separated into a section lodging an electric motor and a compression mechanism and a section where a discharge pipe is provided. Refrigerating machine oil is stored in the section including the discharge pipe in order to ensure the requisite amount of refrigerating machine oil. An oil separation mechanism is provided in the passage of the refrigerant gas so that refrigerant gas containing little amount of refrigerating machine oil may be sent out from the discharge pipe.

Abstract: A compressor oil management and separation system for refrigeration installations, including a main oil storage tank, a pump, valves and remote control means for selectively directing oil from the tank to any one or more of several compressors. Oil separation units are connected for collecting oil from low pressure refrigerant and delivering such separated oil to the tank for reuse or disposal. Each oil separation unit includes a collection vessel, valves for selectively alternately connecting the vessel with low pressure refrigerant and the tank, and means for increasing pressure within the vessel for forcing oil toward the tank.

Abstract: An oil collector unit of a refrigerant recovery system includes a housing, an interior middle vertical wall disposed in the housing, an interior middle horizontal wall disposed in the housing and intersecting the interior vertical wall and defining left and right pairs of upper and lower chambers on opposite sides of the middle vertical wall having passageways between the upper and lower chambers at opposite ends of the middle horizontal wall which are spaced from the opposite ends of the housing, and a plurality of tubes connected in flow communication with selected ones of the chambers of the housing so as to define a circuitous flow path through the chambers of the housing permitting travel of a fluid mixture of refrigerant and oil therethrough and separation of oil from refrigerant therewithin.

Abstract: A method of lubricating a compression type refrigerating system comprising a compressor, a condensor, an expansion valve or a capillary tube and an evaporator, involves the use of lubricants having a kinematic viscosity of 5 to 500 cSt at 40.degree. C. and an interfacial tension of 8 dyne/cm or above in combination with a mixed refrigerant comprising 1,1,1,2-tetrafluoroethane and 1,1-dichloro-2,2,2-trifluoroethane or chlorodifluoromethane as an essential component in the system.

Abstract: This invention seeks to provide a cooling device for a hermetic motor-driven compressor, which may effectively carry out not only lubrication, but cooling of a piston and a cylinder by making refrigeration oil in a hermetic casing to circulate in the interior of the piston for removing frictional heat generated between the piston and the cylinder during operation. To this end, the device comprises a crankshaft for drawing up and spouting out the refrigeration oil circulating in the interior of the piston to cool the piston, and a movable portion formed integrally with the connection portion and linearly reciprocably movable in the cylinder for compressing refrigerant gas.

Abstract: The present invention provides an improved oil separator in which the oil/refrigerant mixture is caused to flow through two different filter elements. Each of the filter elements is contained in a separate chamber within the separator. A valve assembly is also provided that selectively permits only oil to flow from the first chamber to an oil collection area in the second chamber. The valve assembly regulates the flow of collected oil to the collection area such that the oil/refrigerant mixture cannot escape from the first chamber except by flowing through the filter element of the second chamber. In one embodiment, the valve assembly can include an elongated oil drain extending from a first end adjacent to an oil drain aperture in a dividing wall separating the first and second chambers to a second, open end. A valve seat is formed on the second end of the oil drain.

Abstract: An oil purification apparatus for use in conjunction with a refrigeration system. The oil purification apparatus includes an isolation tank for receiving a quantity of contaminated oil from the refrigeration system and holding the oil isolated from the refrigeration system. A separation system including a heater and an agitation mechanism reclaims refrigerant contaminant entrained in the oil. A vapor loop selectively conveys the reclaimed refrigerant from the oil purification apparatus to the refrigeration system.

Abstract: A refrigeration system of the type having an economizer cycle is provided with a null cycle, in addition to heating and cooling cycles, without shutting a compressor prime mover down, to preserve air flow in a conditioned space. First, second and third controllable valves respectively: (1) select main and auxiliary condensers, (2) open and close a liquid line, and (3) open and close a line which provides a warm liquid to an economizer heat exchanger. The valves are controlled in at least one predetermined open/close pattern during a null cycle, and preferably in a plurality of selectable predetermined open/close patterns, to provide a null cycle at any instant which substantially matches the net heat gain or loss taking place in the conditioned space. Thus, the temperature of the served space will be more apt to remain in a null temperature range close to set point, providing smoother and more accurate control over the temperature of the conditioned space for longer shelf life of perishables stored therein.

Abstract: Means are provided to separate liquid particles from a flowing gas and liquid particle mixture which does not require any moving parts. A housing receives the gas and liquid particle mixture and includes a porous membrane interface which separates a higher pressure area from a lower pressure area within the housing. An elongated spiral conduit forming an area of higher pressure provides a flow path from an inlet to an outlet of the housing. The liquid particles in the flowing gas and liquid particle mixture are urged by their flow through the elongated spiral conduit into contact with the porous membrane interface. The liquid particles coat the porous membrane interface and form a film created by the surface tension of the liquid. Liquid from particles which continue to come into contact with the porous membrane interface is urged through the membrane into the lower pressure area while gas is retained in the higher pressure area. The separated liquid and cleansed gas can be removed from the housing for reuse.

Abstract: A muffler and an oil separator located within a common shell. The muffler includes a plurality of chambers tuned to different frequencies. The flow path is serially through the muffler into contact with an agglomerating pad followed by flow through demister pads and a coalescer.

Abstract: The invention resides in improvements to refrigeration systems which rely on circulation of refrigerant gas through compression and expansion phases, and thereby discharging heat from a fluid to be cooled. The invention includes a subcooler (38) in the refrigerant loop, downstream of the refrigerant condenser (34) and a gas trap (36) between the condenser (34) and the subcooler (38), that assures temperature drop in the subcooler (38). The invention also comprehends a shut-off valve (44) between the compressor and the heat source heat exchanger (28). The invention further includes a high capacity-to-volume oil to air heat exchanger (48), for cooling the lubricating oil in the oil loop (26). Preferred refrigerant is ammonia. Incorporating the above improvements into refrigeration systems enables an overall reduction in system sizing. Such systems, having heat exchange capacity of at least 200,000 Btu/hr., up to at least 500,000 Btu/hr.

Abstract: An air conditioning system (10) for an aircraft, the air conditioning system (10) having a separator (14) located between the high pressure side of a compressor (12) and a condenser (18). A timer (34) activated normally open solenoid (32) is located on a separator drain line 28 to periodically dump the lubricant accumulated in the separator (14) back into the compressor (12).

Abstract: The present invention relates to the cooling and heating dual-purpose air conditioner, and more particularly to the heat pump type cooling and heating dual-purpose air conditioner wherein the stand-by control is performed in order to prevent the viscosity increases caused by the lubricating oil freeze in the compressor occurring at the initial cooling operation stage and therefore the smooth drive of a compressor in an air conditioner is performed by the preventing of the lubricating oil freeze.

Abstract: A compression refrigerating system includes an oil and air separator spaced between the refrigerant receiver and the evaporators of the system, and the refrigerant of the mixture of oil and refrigerant contributes to the cooling of the refrigerant circulating to the evaporators by the evaporation in the oil separator.

Abstract: A refrigerant apparatus having a compressor, a condenser, an expansion value, evaporator and an oil repellent coat. An oil repellent coat is coated inside of a low pressure refrigerant passage which lubricant is easy to adhere so that lubricant is prevented from staying inside of the refrigerant passage. Since the oil repellant coat is low affinity for oil, luricant forms guttulate on the oil repellent coat by surface tension. Since the guttulate is easy to move on the inside wall with a flow of the refrigerant, it is prevented lubricant from staying on the inside wall.

Abstract: An oil recovery system for a closed type centrifugal refrigerating machine. The refrigerating machine includes a compressor that has an oil sump below the suction side thereof, a condenser that liquefies compressed refrigerant gas by cooling, an evaporator that evaporates the liquefied refrigerant, a suction volume control valve that controls the volumetric flow of refrigerant gas sucked into the compressor from the evaporator, recovery means for recovering oil from the oil sump to an oil tank in a lubricating system, and control means for starting or stopping the compressor in accordance with the magnitude of refrigeration load. The oil recovery system comprises valve opening control means for controlling the opening of the suction volume control valve such that a decrease in the amount of oil recovered to the oil tank is compensated for when the number of times of start or stop of the compressor per unit of time exceeds a set number.

Abstract: The normal path for the flow of oil/refrigerant being reclaimed from the cooler is changed during periods of low load operation such that the oil/refrigerant mixture flows directly from the cooler to the ejector rather than by way of normal suction housing pass. This is accomplished by valve means responsive to either a pressure differential or the guide vanes position, either of which is indicative of the load condition.

Abstract: An oil separator used in a refrigerating system. The oil separator comprises a body for forming a centrifugal oil separating chamber and an oil storage chamber, with a separating plate dividing the chambers. An inlet passage is connected tangentially to the oil separating chamber, to cause a swirl in the chamber, and a medium outlet passage extends inwardly from an end wall into the oil separating chamber. An oil outlet passage(s) is provided in the separating plate at a position near a periphery thereof. The oil separator body is formed integrally with the compressor housing and a ring member is fitted in an inner surface of the oil storage chamber, and a helically shaped narrow groove is provided on the outer surface thereof to form an oil returning passage. Also, the oil outlet passage can be provided in the separating plate at a position lower than a highest level of the oil storage chamber, thereby allowing the chambers to be arranged in a horizontal side by side relationship.

Abstract: A system and process of parallel compressors for compressing fluids miscible with oil. The present invention utilizes parallel-coupled compressors, wherein each compressor comprises a crankcase chamber, discharge chamber, suction chamber, and ejector which operate independent of one another. Means are provided for coupling the ejector in the return of the lubrication pump oil within the crankcase chamber and the maintenance of that oil level in all the crankcase chambers regardless of each compressor capacity and quantity with which they are operating or are not operating. The transference of suction chamber oil to crankcase chamber is performed by the ejector via energy from the lubrication pump contained within each crankcase chamber. Further, transference of oil from suction chamber to crankcase chamber via an ejector performs all necessary equalization functions.

Abstract: A helium gas compressing apparatus constructed in such as manner that: an oil separator in a high-pressure gas passage is connected to a low-pressure gas passage; and oil return path having first and second branch paths is provided between the high- and low-pressure gas passages; a capillary tube is installed in one of the two branch paths; and an adjustment valve is installed in the other branch path to adjust the pressure difference between the supply gas in the high-pressure gas passage and the return gas in the low-pressure gas passage. Because of this construction, the adjustment valve can be manipulated from outside to make fine adjustments on the pressure difference or change it to a desired value with ease even during operation of the apparatus, thereby adjusting the refrigerating capability of a helium refrigerating machine connected to the apparatus and the power consumption of the helium gas compressing apparatus.

Abstract: A device for separating oil from a gas is provided which includes a housing forming a peripheral wall with an inlet at a top end of the housing for receiving an oil/gas mixture, a gas outlet formed by a conduit extending through the top end of the housing and an oil outlet at a bottom end of the housing. Within the housing there is a helical wall extending between the gas outlet conduit and the peripheral wall to cause the oil/gas mixture to flow in a largely circumferential path along the peripheral wall. Between the helical wall and the peripheral wall there is provided a mesh screen for collecting and separating the oil from the oil/gas mixture. The collected oil drips from the screen to a baffle with apertures therein which directs the oil therethrough for receipt in an oil collection zone below the baffle. The gas outlet conduit has an opening above the baffle for permitting relatively oil-free gas to exit the oil separator.

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.

Abstract: An oil recovery system for refrigeration apparatus of the type in which an oil lubricated screw compressor is oriented with a suction inlet in communication with an evaporated chamber positioned under the compressor so that under conditions of low capacity compressor operation, lubricating oil may fall from the compressor through the suction inlet thereof and into the evaporator. The recovery system takes advantage of an existing suction distribution tray in the upper region of the evaporator chamber of such systems, normally used to assure distribution of gaseous refrigerant to the suction inlet of the compressor, by removing oil dropping into the tray and returning it back to the compressor. An existing by-pass eductor loop for returning liquid refrigerant from the evaporator to the compressor is extended by a valve controlled branch to a second eductor for withdrawing the oil from the tray and returning it to the compressor.

Abstract: Apparatus for protecting a compressor operating in a refrigeration device such as a heat pump includes a heater for maintaining lubricating oil contained in a crankcase of the compressor at a preselected temperature that will prevent the oil from absorbing any refrigerant. A control circuit is connected to an alternating current source of electrical power for controlling the operation of the compressor. The control circuit includes a thyristor having a blocking state and a conducting state. If the heater fails to operate, the thyristor will be disposed in the blocking state thereby preventing the compressor from operating. The control circuit also includes a trigger for changing the thyristor from the blocking state to the conducting state, and a full wave bridge or rectifier for converting the voltage drop across the thyristor from an alternating current voltage to a direct current voltage.

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

Abstract: A refrigerant handling system that includes a compressor having an inlet and an outlet, a condenser for withdrawing heat from and at least partially condensing refrigerant passing therethrough, and a compressor oil separator connected between the compressor outlet and the condenser for separating oil from refrigerant passing to the condenser. The compressor oil separator takes the form of a closed canister having an open internal volume, a vapor inlet and a vapor outlet at an upper portion of the canister, and an oil drain at a lower portion of the canister. A refrigerant coil is mounted externally of the canister in heat exchange relationship with the canister sidewall. The vapor inlet, vapor outlet and refrigerant coil are connected in series between the compressor outlet and the condenser coil such that heat of refrigerant passing through the coil heats the canister internal volume to prevent condensation of refrigerant therein.

Abstract: An oil separator is provided for separating oil from a refrigerant gas and returning the oil to a compressor. The separator includes a housing which has means associated therewith for conducting a mixture of refrigerant gas and oil into the housing and therein separating the oil from the gas. The separated oil is stored in a reservoir forming a part of the housing. A plurality of oil pickup devices are located within the oil reservoir. Each of the oil pickup devices has an oil pickup opening associated therewith. The oil pickup openings are located at different depths within the oil reservoir. The pickup devices are designed so that they are substantially more receptive to the flow of lubricating oil therethrough than to the flow of refrigerant gas. In one embodiment, the oil pickup devices are capillary tubes having their open ends located at different depths within the oil reservoir.

Abstract: An oil separator for an air-cooled refrigeration system employing a screw compressor includes a U-shaped housing the bottom of which defines an oil sump and the upstanding leg portions of which are connected by flow splitting apparatus. The flow splitting apparatus divides and tangentially delivers portions of a mixture of compressed refrigerant gas received from the compressor, and in which oil is entrained, into the upper region of each leg portion. The tangential delivery of the mixture into the leg portions and the centrifugal force created thereby causes the entrained oil to be separated from the gas at two distinct locations in the separator. The separated oil drains along the inner walls of the leg portions of the separator to a common sump while the compressed refrigerant gas from which the oil has been separated exits each of the leg portions through open-ended conduits which extend into the leg portions.

Abstract: A rotary displacement compression heat transfer system and method for improving its efficiency includes a rotary displacement compressor for compressing a refrigerant, a condensor connected with the outlet of the compressor, an evaporator connected with the inlet of the compressor, an oil pump for injecting oil into the compressor, an oil separator for separating out the oil and recirculating it to the compressor, a non-chlorinated hydrocarbon refrigerant, and a synthetic oil ingredient in the oil providing an inverse solubility characteristic where a mixture of the refrigerant and oil has two immiscible phases in the compressor's operating temperature range and has only one dissolved liquid phase at a temperature in the evaporator's operating range at a weight concentration of oil less than about 5%.

Abstract: An oil separator suitable for separating oil from vaporized refrigerant leaving the high pressure discharge side of a refrigerant compressor, and for returning the separated oil to the compressor crankcase. The oil separator includes an elongated housing having a longitudinal axis. Oil separation stages and a capillary tube are disposed within the housing. The capillary tube has a first end into which oil may flow, and a second end in fluid flow communication with an oil return outlet on the housing. The first end of the capillary tube and the oil return outlet are positioned relative to one another such that the longitudinal axis of the housing may be oriented at any selected angle in a range of ninety degrees between horizontal and vertical orientations. The capillary tube has a bore and length selected such that a predetermined refrigerant flow rate is created which carries oil to the crankcase.

Abstract: Sound attenuating liquid-gas separation apparatus includes nested elements which are tuned to abate noise in general and at predetermined frequencies in particular in a screw compressor assembly. The apparatus includes a helical flow path defined internal of an outer shell. The shell is selectively perforated at its downstream end to allow for the egress of separate oil from it. The apparatus includes a columnar, open-ended cylindrical member internal of the outer separator shell and a discharge conduit which penetrates both the separator shell and the open end of the columnar cylindrical member disposed within the shell to create the nesting which both contributes to the oil separation proces and abates noise. By selectively dimensioning and therefore "tuning" the nested members in accordance with the characteristics of the particular compressor with which they are used, compressor assembly noise abatement at predetermined frequencies is accomplished.

Abstract: A control apparatus for a multi-air-conditioner system provided with a freezing cycle wherein refrigerant is supplied from a common outdoor unit to a plurality of indoor units via respective control valves. In order for a compressor to recover refrigerant and oil contained therein remaining in an indoor unit under interception, the control valve of the indoor unit under interception is opened cyclically to a degree of opening corresponding to the rated capacity of the indoor unit for the predetermined time while circulating the refrigerant cyclically for a predetermined time to the indoor unit.

Abstract: A rotary displacement compression heat transfer system and method for improving its efficiency includes a rotary displacement compressor for compressing a refrigerant, a condensor connected with the outlet of the compressor, an evaporator connected with the inlet of the compressor, an oil pump for injecting oil into the compressor, an oil separator for separating out the oil and recirculating it to the compressor, a non-chlorinated fluorinated refrigerant, and a synthetic oil providing an inverse solubility characteristic where a mixture of the refrigerant and oil has two immiscible phases in the compressor's operating temperature range at a weight concentration of oil in the range of about 10-60% and has only one dissolved liquid phase at a temperature in the evaporator's operating range at a weight concentration of oil less than about 5%.

Abstract: In a variable speed air conditioning system driven by an electronically commutated DC motor, the large DC capacitor associated with the compressor motor drive discharges to the normally AC powered compressor oil sump heater upon the loss of AC power to the system.

Abstract: A system for refrigeration comprises: a compressor having an inlet, an oil sump, and an outlet; a condenser having an outlet, and an inlet connected to the compressor outlet; an expansion valve operable for controlling refrigerant flow in the system and having an outlet, and an inlet connected to the condenser outlet; an evaporator having an inlet connected to the expansion valve outlet and an outlet connected to the compressor inlet; and a control unit for operating the expansion valve to maintain a predetermined temperature differential between the temperature of oil in the oil sump and the saturated temperature of the refrigerant in the vicinity of the compressor inlet. The temperature differential is selected such that refrigerant in liquid phase in the compressor does not excessively dilute the compressor oil.

Abstract: An outdoor unit has at least two variable-capability compressors and has an outdoor heat exchanger coupled to the compressors having lubricating oil supplying sections coupled together by an oil-balancing member. A plurality of indoor units are each coupled to the outdoor unit for forming a refrigerating cycle and each have at least an indoor heat exchanger and an output section for outputting demand capability data according to an air conditioning load of the indoor heat exchanger. In accordance with the demand capability data, a controller generates a parallel operation command for parallel operation involving both of the compressors of the outdoor unit with capability according to a sum of the demand capability data from the indoor units.

Abstract: The present invention provides a method and apparatus for recovering and purifying a refrigerant containing lubricant from a refrigerant system. The apparatus includes an evacuation means for evacuating the refrigerant and lubricant from the refrigerant system. A reservoir means receives the evacuated refrigerant and lubricant. A means allows lubricant and refrigerant to exit the apparatus and enter the refrigerant system.

Abstract: A lubricant composition with decreased solubility in a liquid refrigerant and increased foaming characteristics useful in refrigeration systems to promote oil return to a compressor. A lubricant composition comprises a base lubricant, synthetic paraffinic oil, and a foaming agent. These ingredients are blended in predetermined amounts, so that when the lubricant is used in the refrigeration system, an oil rich layer will form atop the liquid refrigerant in the system's flooded evaporator, and a thick, stable foam will form when vaporized refrigerant boils up through the oil rich layer. The oil foam is then drawn through a connection at the top of the flooded evaporator and returned to the compressor.

Abstract: A heat pump having reversible heating and cooling cycles for circulating a refrigerant therein for adding heat to and removing heat from space, the heat pump comprising a heat exchanger for adding heat to and removing heat from air passed over it, a condenser/evaporator coil for removing heat from or adding heat to refrigerant; and a compressor for circulating refrigerant. The heat pump further comprises a conduit for conducting refrigerant to the heat exchanger during the heating cycle and conducting refrigerant from the heat exchanger during the cooling cycle. A first line supplies the conduit with refrigerant during the heating cycle and is smaller than the conduit so that the refrigerant decelerates, causing oil that may have been picked up by the refrigerant to drop out. A second line also conducts refrigerant from the conduit during the cooling cycle. This line is larger than the conduit so that the refrigerant decelerates during, causing oil that may have been picked up by the refrigerant to drop out.

Abstract: This invention is comprised of an improved cryogenic refrigeration compressor which contains an externally adjustable relief valve positioned between the helium supply line and the helium return line whereby if the pressure within the helium supply line exceeds a predetermined value the externally adjustable relief valve opens up and allows helium to flow from the supply line to the return line. The relief valve is externally adjustable. It is comprised of a coaxial inlet and outlet member and externally adjustable spring compression means. Together they define a duct. Within the inlet member is a poppet valve and a spring. The spring exerts bias against the valve to close the valve against present fluid pressures.

Abstract: Oil separation for a horizontal refrigeration screw compressor is achieved in a series of steps which achieves nearly oil-free refrigerant gas. The refrigerant is discharged from the compressor into a generally cylindrical shell which is divided into three chambers. A generally horizontal, but slightly tilted, divider plate unequally divides the cylindrical shell into two chambers for the greater portion of the cylindrical shell. A cylindrical chamber at the end of the cylindrical shell provides fluid communication between the other two chambers. The compressor discharge is located in the lower and larger chamber which is a segment of a circle portion which also contains the oil sump. A discharge deflector turns the compressor discharge flow at least 90.degree., but as much as 135.degree., and causes it to impact upon the lower surface of the divider plate and depositing oil thereon. The flow striking the divider plate is deflected 180.degree. and is caused to turn approximately 90.degree.

Abstract: The invention relates to a method for a refrigerant system having a circulation circuit comprising a screw compressor (1), a condenser (4), an expansion valve (5) and an evaporator (6). In a refrigerant process, in which an oil injected compressor is connected it is impossible to prevent oil from flowing together with the refrigerant out into the circulation circuit, which among others impairs the operation of the evaporator. According to the invention a drastic reduction of the amount of circulating oil has been obtained together with an improved cooling of the compressor by supplying the low pressure side of the compressor with refrigerant liquid with a pressure and temperature lower than the pressure and temperature of the refrigerant in the condenser in such amounts per unit of time that the required cooling and sealing of the compressor is obtained, the effect of the circulating oil being restricted merely to lubricating.

Abstract: A refrigeration system has multiple compressors in a parallel arrangement. The pressures in the shells of operating compressors are maintained equal by the controlled delivery of suction gas and entrained oil to the shells of individual operating compressors in quantities which maintain the pressures therein equal. A valve, directly responsive to compressor shell pressures, occludes the flow of suction gas to the shell of an operating compressor in which the pressure is greater than that found in the shell of another operating compressor so as to equalize the pressures in the compressor shells. The equalizing valve arrangement directs and apportions essentially the entire amount of suction gas to the shells of operating compressors while cutting off the flow of suction gas into the shells of non-operating compressors.

Abstract: Oil normally having refrigerant gas entrained therein is drawn from a sump. A portion of the oil is returned to the sump to agitate the oil in the sump to enhance gas separation therefrom. The remainder of the oil is subjected to centrifugal separation to remove the entrained refrigerant. The separated refrigerant is vented while the separated oil is fed to the lubrication system where contaminant removal takes place.

Abstract: An air conditioner including a cooling medium compressor, a condenser, an expansion valve and an evaporator, these being connected one another by a cooling medium capillary tube to circulate a cooling medium, whereby an oil returning mechanism of an evaporator for the air conditioner is characterized in that there is provided an oil reservoir for reserving a lubricating oil after oil separation at a lower part of the evaporator, the oil reservoir and an outlet tube for guiding the cooling medium passed through the evaporator to the cooling medium compressor being connected by an oil returning tube, the oil returning tube being provided with a controlling valve, when a pressure differential between the oil returning tube and the outlet tube is a predetermined level or more, the controlling valve being closed to enhance a normal flow of the cooling medium from the evaporator to the cooling medium compressor, when the pressure differential is a predetermined level or less, the lubricating oil staying in the oil

Abstract: In a cryogenic refrigeration system, a hermetic refrigerant compressor pump is used to compress helium. The compressor pump 10 is oil cooled by a heat exchange jacket 46 surrounding a compressor housing 28. Oil from an oil sump 30 within the compressor housing 28 is pumped through an external heat exchanger 44 where it is cooled, to the heat exchange jacket 46. From the heat exchange jacket 46, oil is recycled back to the oil sump 30. Pressure developed by the compressor pump 10 is used to pump the oil.

Abstract: A device for collecting lubricating oil in the turbo-refrigerator comprising an evaporator, a condenser, a compressor, a suction vane arranged in front of the compressor to control the amount of refrigerant gas sucked, a mechanism for returning the lubricating oil, which remains in a space located downstream the suction vane, back to an oil reservoir, and a tube for communicating the space located downstream the suction vane with a space on the evaporation surface of the evaporator.

Abstract: The slide valve assembly by which the capacity of an oil-injected screw compressor is controlled includes a valve portion connected to a piston. The valve portion is located in the screw rotor housing while the valve actuating piston is located within a pressure housing interior of a centrifugal oil separator in what would otherwise be unused space. The rod connecting the valve portion and piston penetrates the discharge port of the compressor. The piston is actuated and the compressor is loaded by directing separated oil from the oil sump in a sealed sump housing into the pressure chamber within the centrifugal oil separator. The oil separator is located within the sealed oil sump housing. Oil is vented from the pressure housing into a suction area within the rotor housing to unload the compressor. Such oil is sucked into the working chamber of the compressor where it assists in the cooling, lubricating and sealing of compressor components.

Abstract: In a refrigerating machine, a reservoir heated by an electric motor driving a compressor contains oil up to certain level. The reservoir is fed with refrigerating liquid complemented with oil. The liquid vaporizes while oil falls down in the liquid state. A number of lubrification conduits connect individual bearings of the compressor with the reservoir above the oil level on the one hand and with the reservoir below the oil level through a micro-orifice on the other hand, so as to send to the bearings refrigerating gas loaded with an oil mist. The bearings are in fluid communication with the intake of the compressor.