Abstract: A miniature mixed gas refrigeration system and method of operation are disclosed. An optimum gas mixture is formulated from a group of component fluids, according to calculated thermodynamic properties of a group of candidate fluid mixtures. The gas mixture is pressurized by a compressor to a pressure less than 420 psia, for safety reasons. The compressed gas mixture is passed through a primary heat exchanger, and then through a primary-to-secondary heat exchanger, to precool the gas mixture. The secondary side of the primary/secondary heat exchanger is cooled by a secondary Joule-Thomson refrigeration system. Properly sized flow restrictions in the primary side of the primary/secondary heat exchanger can solidify and trap liquid contaminants that may be in the gas mixture. The gas mixture exiting the primary outlet of the primary/secondary heat exchanger passes to a primary Joule-Thomson expansion element where the high pressure gas is expanded isenthalpically to a lower temperature at least as low as 183K.

Abstract: There is disclosed a condenser for use in an air conditioning system. The condenser includes a receiver dryer fluidly communicating with it. The receiver dryer includes a fluid inlet for receiving a two-phase refrigerant mixture from the condenser and two outlets, both of which direct refrigerant back to the condenser after phase separation.

Abstract: A low-temperature refrigeration system (10) is disclosed for accurately maintaining an instrument (11) with a time varying heat output at a substantially constant predetermined cryogenic temperature. The refrigeration system (10) controls the temperature of the instrument (11) by accurately adjusting the pressure of coolant at a heat exchanger interface (12) associated with the instrument (11). The pressure and flow of coolant is adjusted through the use of one or two circulation loops and/or a non-mechanical flow regulator (24) including a heater (32). The refrigeration system further provides a thermal capacitor (16) which allows for variation of the cooling output of the system (10) relative to a cooling output provided by a cooling source (14).

Abstract: A centrifugal type separator is disposed on a downstream side of a temperature-operating type expansion valve. Liquid-phase refrigerant separated herein is again pressure-reduced by an aperture resistance and thereafter inducted to an inlet side of the evaporator by means of a liquid-phase refrigerant discharge passage. Meanwhile, gas-phase refrigerant separated by the separator is returned directly from a gas-phase refrigerant discharge passage to an evaporator outlet side passage, and after being united with superheated gas-phase refrigerant evaporated by the evaporator, is taken into a compressor. A temperature-sensing tube of the expansion valve is disposed further on the downstream side of the foregoing union location so as to enable the temperature of the superheated gas-phase refrigerant evaporated by the evaporator to be sensed accurately.

Abstract: A long-term thermally stable cryostat (40). The cryostat (40) pre-cools an incoming high-pressure gas, converts it to a cold liquid, contains the liquid, and cools an item by allowing the liquid to acquire heat from the item and boil into an exhaust gas, while maintaining an absolute pressure in the container to reduce thermal noise due to altitude-induced pressure changes. In specific embodiments, the cryostat (40) includes a hollow mandrel (52) disposed within a cooling volume (64) mounted within a dewar vacuum area (58). Pre-cooling fins (44) spiral around the hollow mandrel (52) within the cooling volume (64) and circulate an incoming high-pressure gas around the mandrel (52). A flow restrictor (60) receives the incoming gas from the pre-cooling fins (44) and releases it into the cooling volume (64), thereby converting the incoming gas into a cold liquid which can acquire heat from the item and boil into an exhaust gas.

Abstract: A gas-liquid separator for a heat pump type air conditioning system using a gas-injection cycle, which system can switch its mode of operation between heating and cooling modes, includes a reservoir for receiving refrigerant in a gas-liquid two-phase flow, an exit port which opens at a upper portion of the reservoir and allows a refrigerant gas to flow out of the reservoir, first and second ports which are provided at a upper part within the reservoir above the level of a refrigerant liquid and allows the refrigerant to flow into and out of the reservoir.

Abstract: Temperatures of 0.2.degree. K or lower are achieved by feeding 3He and 4He separately into a mixing chamber (5) in an enclosure (3) in which the temperature is held at around 2.degree. K. The endothermal dilution of 3He into 4He provides the required cold. The resulting mixture (M) passes out of the mixing chamber and the enclosure while cooling the incoming fluids by means of exchangers (1, 12, 4). To compensate for thermal losses, the mixture (M) also undergoes Joule-Thompson expansion (12) optionally followed by evaporation (13), preferably between about 1.5.degree. and 2.5.degree. K, and the resulting cold is used to lower the temperature of the incoming fluids from well above 4.degree. K to between 1.5.degree. and 2.5.degree. K, which is close to the temperature prevailing inside the enclosure (13) containing the coldest point (6) in the circuit.

Abstract: A centrifugal type separator is disposed on a downstream side of a temperature-operating type expansion valve. Liquid-phase refrigerant separated herein is again pressure-reduced by an aperture resistance and thereafter inducted to an inlet side of the evaporator by means of a liquid-phase refrigerant discharge passage. Meanwhile, gas-phase refrigerant separated by the separator is returned directly from a gas-phase refrigerant discharge passage to an evaporator outlet side passage, and after being united with superheated gas-phase refrigerant evaporated by the evaporator, is taken into a compressor. A temperature-sensing tube of the expansion valve is disposed further on the downstream side of the foregoing union location so as to enable the temperature of the superheated gas-phase refrigerant evaporated by the evaporator to be sensed accurately.

Abstract: The present invention relates to an energy converter for transferring thermal energy from a low heat source to a high heat source using a mixed medium for the purposes of increasing thermal energy transfer efficiency. The present invention improves performance of an evaporator and a condenser, reduces production cost of the device, improves performance over a wide range even with partial loads, and provides a highly efficient and polyfunctional energy converter having function as a refrigerator and a heat pump with one cycle, and function as a generator.

Abstract: A cryogenic surgical apparatus comprises: a) a plurality of probes, each having a contact surface, each of which probes is suitable for creating fast temperature changes at the said contact surface; b) temperature generation means, coupled to each of the said probes, being capable of creating cryogenic and above 0.degree. C. temperatures at the said contact surface of the said probe; and c) temperature control means, to control the said temperature generation means.

Abstract: A method for deflecting a fluid supply using a skirt. The skirt comprising a remote and a close portion (with respect to distance from a fluid impinged surface). The skirt is located in close proximity to a surface to be impinged by the fluid. The deflection method is especially suited for use in conjunction with a Joule-Thomson cryostat and can also be used in conjunction with more than one cryostat for cooling of electronic devices. The remote portion of the skirt is disposed around the nozzle or nozzles of the fluid supply so that each fluid supply (or nozzle) extends through a hole in the remote portion of the skirt. The interior surface of the close portion of the skirt extends closer to the fluid impinged surface than each nozzle. The method efficiently wets the impinged surface with a fluid providing a measure of control over the outward velocity of the fluid as it progresses along the fluid impinged surface.

Abstract: An integral combination of expansion valve and evaporator in a cryostat using a single support member. The valve includes two flow orifices, one orifice being used primarily for steady-state operation and the other orifice being used only during cool-down. An actuator having a high coefficient of thermal expansion moves a needle positioned in the cool-down orifice such that a large orifice flow area at the start of cool-down is automatically and continuously reduced as the actuator temperature decreases as refrigerant is throttled through the orifice. Within a range of approximately 30 K from the desired steady-state evaporator temperature, the needle completely blocks the cool-down orifice. Then, refrigerant flows through the steady-state orifice which has a remotely adjustable needle. In the final stage of cool-down, the refrigerant system is entirely controlled by the steady-state orifice and its associated needle.

Abstract: A skirt for deflecting a fluid supply comprises a remote and a close portion (with respect to distance from a fluid impinged surface). The skirt is located in close proximity to a surface to be impinged by the fluid. The skirt is especially suited for use in conjunction with a Joule-Thomson cryostat and can also be used in conjunction with more than one cryostat for cooling of electronic devices. The remote portion of the skirt is disposed around the nozzle or nozzles of the fluid supply so that each fluid supply (or nozzle) extends through a hole in the remote portion of the skirt. The interior surface of the close portion of the skirt extends closer to the fluid impinged surface than each nozzle. The skirt efficiently wets the impinged surface with a fluid providing a measure of control over the outward velocity of the fluid as it progresses along the fluid impinged surface.

Abstract: A stacked multistage Joule-Thomson (J-T) cryostat is described in which each stage comprises a thermally conducting material plate member with fluid passages formed therein and in which the stages are stacked one above the other but separated from each other by thermally insulating standoff supports. Each successive stage in the stack is cooled to successively lower temperature zones by J-T expansion and liquefaction of different coolant gases. Each stage has a restricting passageway connected to a different high pressure gas coolant supply and forming a throttle valve opening into two-phase (liquid-vapor) coolant reservoir passages. The reservoir passages in all but the coldest stage are in heat exchange relation with the high pressure supply passages of the lower boiling temperature coolant gases. The coldest stage is in heat exchange relation with a cold surface on which a device to be cooled can be mounted.

Abstract: An apparatus for creating controlled temperature changes on a contact surface, comprises: a) a probe having a contact surface, which probe is suitable for creating fast temperature changes at the said contact surface; b) temperature generation means, coupled to the said probe, being capable of creating cryogenic and above 0.degree. C. temperatures at the said contact surface of the said probe; and c) processing means to control the said temperature generation means according to predetermined operating conditions.

Abstract: A short-term thermally stable cryostat (40). The cryostat (40) pre-cools an incoming high-pressure gas, converts the gas to a cold liquid, and cools an item by allowing the liquid to acquire heat from the item and boil into an exhaust gas, while maintaining a constant flow rate of the exhaust gas to reduce thermal noise due to flow rate modulation. The cryostat (40) includes an evacuated space (58) therein containing the item to be cooled and an inner cooling volume (64). Pre-cooling fins (44) spiral around a hollow mandrel (52) within the cooling volume (64) and circulate an incoming high-pressure gas around the mandrel (52). A flow restrictor (60) receives the incoming gas from the pre-cooling fins (44) and releases it into the cooling volume (64), thereby convening the incoming gas into a cold liquid which can acquire heat from the item and boil into an exhaust gas.

Abstract: A hybrid thermoelectric/Joule-Thomson cryostat with a finite cryogenic gas supply is configured to greatly increase the cold operating time of a infrared detector array. A Joule-Thomson cryostat is located within a dewar vessel along with the infrared detector array to be cooled. Cryogenic gas from a cryogenic gas source is pre-cooled by a thermoelectric cooler at a location remote from the dewar vessel. Final cooling of the cryogenic gas is then performed by a demand flow Joule-Thomson cooler which has the ability to provide the low temperatures necessary for operation of an infrared detector. The operating period of the cryogenic gas supply and Joule-Thomson cryostat are increased by the cryogenic assistance of the thermoelectric cooler.

Abstract: A demand-flow Joule-Thomson cryostat 10' adapted for use with multiple coolants uses a replaceable coolant supply reservoir 21' to fill a coolant flow control bellows 17' within the cryostat with the same coolant used to provide refrigeration to the thermal load 15'. Upon termination of the cooling cycle, the bellows 17' is drained of coolant and thus prepared for operation from a different coolant supply 21' that may contain a different cryogen.

Abstract: The air conditioning system contains a refrigerant and comprises a compressor having an inlet and an outlet, a condenser having an inlet and an outlet, an evaporator having an inlet and an outlet and a suction conduit connecting the outlet of the evaporator to the inlet of the compressor where the refrigerant returns to the compressor as a low pressure vapor. A discharge conduit is provided which connects the outlet of the compressor to the condenser where upon removal of heat of the vapor, the gas becomes a high pressure liquid refrigerant. A liquid conduit having an injector and restrictor connects the outlet of the condenser to the inlet of the evaporator. An accumulator having an inlet port and an outlet port is interposed in the suction conduit. A liquid discharge port is also provided in the accumulator. A recirculating conduit connects the discharge port to the liquid conduit.

Abstract: In the cryo-probe, refrigerant is furnished from a high pressure, room temperature supply. Insulation of the refrigerant lines is unnecessary. Refrigerant flows through a pre-cooling heat exchanger in the probe and through a restrictor wherein the pressure drops. In accordance with the Joule-Thompson effect, the refrigerant expands and becomes cold and liquid is applied in the region of the cryo-tip to provide rapid cooling thereof. Expanded refrigerant gas at low pressure reverses direction and flows back from the cold tip in counterflow arrangement through the aforementioned heat exchanger to give a pre-cooling effect to the refrigerant incoming from the external supply. A second tube for conveying warm-up gas is located in the probe and extends to the cold tip. After cryosurgery is complete, the high pressure flow is stopped and warm gas is delivered to the tip in the probe at reduced pressure through the second tube from the same refrigerant supply as is used for cooling.

Abstract: A plurality of cryopumps are installed in each of a plurality of neutral beam injection apparatuses disposed around a nuclear fusion apparatus.The cryopanels of each of the cryopumps are refrigerated by a small helium refrigerating machine. Since the cryopanels are refrigerated from room temperature with cold liquid nitrogen used for refrigerating a heat shield plate, then a small helium refrigerating machine and finally cold liquid helium itself, various valves and a small helium refrigerating machine are disposed. This permits refrigeration of a plurality of cryopumps within a short time, thereby saving the power consumption and improving the operating reliability of a refrigeration system.

Abstract: A system for a cooler comprises: a heat exchange tube receiving a supply of pressurized gas, a gas escape aperture communicating with the interior of the heat exchange tube for permitting escape of the pressurized gas and expansion thereof during cooling mode, and a bypass assembly associated with said heat exchange tube and located after said gas escape aperture which during a cleaning mode enables most of the pressurized gas to exit the heat exchange tube without flowing through said gas escape aperture. The bypass assembly comprises a flush valve which is closed during said cooling mode and which is opened during said cleaning mode. According to a preferred embodiment, the heat exchange tube is helically wound over a cylindrical core and installed inside an insulated housing. The system may also be utilized as a gas purity tester, optionally with an additional gas pressure regulator, wherein a sensor will indicate the extent of the gas purity.

Abstract: The invention relates to a method and apparatus for providing cooling in a reloadable cooling apparatus, which can be used in actuators requiring low temperatures. According to the invention, the loading of at least one cooling element (2, 22, 32), located in the vacuum of the cooling apparatus, is carried out through at least one cooling surface (4, 25, 34), connected to outside the cooling apparatus (1, 21, 31), and the period between two loadings is extended by reducing the transversal area of the supporting member (3, 23, 33) and by reducing the heat conduction distance of the supporting member (3, 23, 33) of the cooling element from the cooling apparatus (1, 21, 33), advantageously by shaping the supporting member (3, 23, 33).

Abstract: An air conditioner has a heating capacity which is increased with a compressor driven by an engine when an outdoor temperature is too low. A work load of the compressor is increased by injecting refrigerant into the compressor via an injecting port. As a result, a load of the engine is also increased so that a coolant temperature is also increased. A large heat radiation from the hot coolant to the indoor air is established at a coolant heat exchanger.

Abstract: The refrigerative probe comprises in combination an insert member fit into, and cooperating with, a probe housing to provide an elongated flowpath in fluid communication with the inner surface of said probe housing. The elongated pathway, being partly defined by a channel formed in the outer surface of the insert member and partly formed by the probe housing, is easily formed in the assembled probe by inserting the insert member into the probe housing.

Abstract: An airborne cryogenic cooling system in which a first cryogenic material located within an on-board container is cooled to the solid state prior to launch a remotely located second cryogen conduited to the container. Immediately prior to becoming airborne connection is broken to the second cryogen and on-board cooling is achieved by venting the container to space environment causing sublimation of the solid first cryogenic, or, alternatively, the container may be left sealed and cooling results from triple-point transition of the solid cryogen.

Abstract: The present invention relates to a particular needle-orifice fluid flow regulator to be used in a cryocooler. The flow regulator comprises a fluid outlet port adapted to receive therethrough a pressurized cooling fluid via a conduit. The needle is arranged for variable positioning relative to said outlet and temperature responsive needle positioning means for positioning said needle relative to said port as a function of temperature, whereby the needle is floatingly mounted relative to said needle positioning means. The positioning means is adapted to apply displacement forces to the needle along an axis which extends through said fluid outlet port, being constructed in a manner which enables to maintain the needle substantially coaxial with the outlet port. The fluid outlet port has a funnel shaped portion with a relatively narrow end arranged for fluid communication with said conduit configured to engage and guide the needle into mating engagement with the fluid outlet port.

Abstract: A closed cycle refrigerating system for cryogenic temperatures using a single stage compressor with a refrigerant comprising a gas mixture. The refrigerating system includes a heat exchanger having a throttling orifice which is arranged to provide refrigeration, and a single stage oil lubricated compressor for compressing the refrigerant. The compressor is typically of the rolling piston type. The refrigerant is a mixture of at least one cryogenic gas having a normal boiling point below 120 degrees K and at least two other gases having normal boiling point temperatures below 300 degrees different from each other and from said one gas. There is also included means for cooling the compressed refrigerant and for circulating the cooled refrigerant to the heat exchanger and its throttling orifice and then back to the compressor. The system does not require any cascaded heat exchangers or intermediate phase separators.

Abstract: The invention provides a controlled connection, or heat switch, between a source of cryogenic cooling and an item which is to be cooled, using control valve means which is not itself subjected to the cryogenic temperatures involved.

Abstract: The throttling sensitivity of a demand flow cryostat may be controlled and stabilized by selectively exposing refrigerant to the surface of a sensor which actuates a refrigerant throttle valve. The sensor is formed of a plastic material such as high density polyethylene which has a high coefficient of thermal contraction.

Abstract: In a cooling apparatus for cooling an object by means of expanding a pressurized gas which is precooled below its inversion temperature, the pressurized, precooled gas is passed through a depressurization outlet and thereby expanded in a manner such that a gas jet exits from the depressurization outlet and is directed towards a surface of the object to be cooled. This surface has a central impingement area which is impinged upon by the gas jet and which is surrounded by a plurality of spiral-shaped outwardly extending ribs. The heat transfer is thereby improved. The gas, which is in the saturated condition, forms a vortex and, as a result, droplets are separated from the gas. This enables utilizing the heat of vaporization of such droplets.

Abstract: A cryostat in which a venting conduit is connected to a reservoir of the cryostat but no venting of cryogen within the reservoir can occur while fluid is flowing under pressure within the heat exchanger of the cryostat.

Abstract: A method and apparatus for cooling and filling a cryogen reservoir with liquid cryogen from the gas/liquid discharge of a heat exchanger. The cryogen reservoir has a cryogen liquid retaining material and a temperature sensing means remote from the heat exchanger. The gas/liquid discharge is located in a region within the reservoir proximate to the temperature sensing means. At least a portion of the discharge is passed through the liquid retaining material to be absorbed, thereby.

Abstract: A modulator in a coolant recirculation line for a refrigerating apparatus. The modulator is used for storing an excess amount of the coolant recirculated in the system. The modulator has a space extending vertically, upward and a bottom end connected to the recirculating line at a position downstream of a condenser, in such a manner that only a part of the coolant passed through the condenser is introduced into the modulator to compensate for variations in the amount of coolant needed for recirculation in the system. The modulator can be arranged in the middle of the heat exchanger, and defines therein a boundary between the liquid phase and the gas phase, for a separation of the gas from the coolant, so that the portion of the heat exchanger downstream of the modulator can operate as a super cooler.

Abstract: A household refrigerator includes a refrigerant circuit having a compressor, a condenser receiving refrigerant from the compressor and a phase separator receiving refrigerant from the condenser. The liquid refrigerant containing portion of the phase separator is connected to the inlet of the freezer evaporator, the outlet of which is connected to the compressor. The vapor refrigerant containing portion of the phase separator is connected to the compressor. The fresh food evaporator is connected to the phase separator to receive liquid refrigerant from the phase separator and to return vapor refrigerant to the phase separator.

Abstract: A dewar (20) useful in rapidly cooling a sensor (28) supported thereon includes a bore tube assembly having a cylindrical dewar bore tube (22) with an end cap (24) at one end to close the bore tube (22). The bore tube assembly is cooled by directing a stream of coolant at the interior of the end cap (24). The sensor (28) is mounted directly to the exterior surface of the end cap (24). A cold shield (34) partially encloses the sensor (28). A cold shield support bracket (38) mounts the cold shield (34) to the cylindrical side walls of the dewar bore tube (22) at a mounting location (36) axially displaced from the end cap (24) and therefore less effectively cooled than the end cap (24), so that heat is extracted from the support bracket (38) and the cold shield (34) less rapidly than from the sensor (28). From an uncooled starting condition, the sensor (28) is cooled to its operating temperature, and the cold shield (34) is cooled to its operating temperature, in about the same time.

Abstract: Cryogenic cooling apparatus comprising an inlet path through which refrigerant gas is caused to flow, a Joule-Thomson expansion nozzle which communicates with the inlet path and in which, in use, a proportion of the refrigerant gas is caused to liquefy and an outlet path communicating with the outlet of the expansion nozzle, the inlet path being in heat exchange relationship with the outlet path. An elongate valve needle cooperates with the outlet side of the expansion nozzle and together with the latter constitutes a valve. A sensor is disposed in the space on the outlet side of the expansion nozzle and is arranged progressively to close the valve as the amount of liquid refrigerant in contact with it increases. The valve needle defines a bypass passage which extends along its entire length and remains open at all times. The apparatus is accommodated within a container, to the outer surface of a portion of the wall of which a thermal load is connected.

Abstract: Oil laden refrigerant is supplied tangentially into an oil separator for a primary removal of oil and then into a coalescer for a secondary removal of oil. Flow between the oil separator and coalescer is controlled by a valve so as to insure that a rapid build up of pressure takes place in the sump to insure adequate lubrication to the compressor.

Abstract: A receiver tank includes a container extending vertically along one of two spaced opposed header pipes of a condenser, a guide pipe extending from a lower end of the one header pipe into the internal space in the container and further extending upwardly within the container, the guide pipe having a number of perforations at an upper portion thereof for guiding a refrigerant into the container, and a refrigerant outlet pipe connected at a lower end portion of the container for discharging the refrigerant from the container. The guide pipe is inserted into the container from the bottom end thereof and guides the refrigerant from the condenser into an upper part of the container. The receiver tank having such guide pipe and container is easy to assembly. The refrigerant flows out from perforations formed at the upper portion of the guide pipe and then falls down toward the bottom of the receiver tank so that a vapor-liquid separation process can be performed efficiently.

Abstract: A cooling apparatus for cooling a pivotable detector contains a first cooler which serves for cooling the detector and contains a depressurization outlet through which pressurized argon which has been precooled below its inversion point, is depressurized and thereby cooled. A second cooler is operated using pressurized methane and serves for precooling the pressurized argon. The second cooler constitutes a Joule-Thomson cooler containing a depressurization nozzle for depressurizing and thereby cooling the pressurized methane, and a countercurrent heat exchanger arranged upstream of the depressurization nozzle for precooling the infed pressurized methane by the depressurized and cooled methane. The first cooler constitutes an expansion cooler containing a depressurization outlet and a heat exchanger upstream of the depressurization outlet for exclusive heat exchange between the pressurized argon and the depressurized and cooled methane.

Abstract: A heat sink apparatus for convective cooling of circuit packages or components by direct impinging fluid operation employing a housing having an inlet port and a plurality of radially fluid flow passages communicating with the inlet port with each passage also having an outlet port. A fluid deflection member is supported with the housing in line with the inlet port and is provided with a deflection surface adapted to redirect the fluid flow from the inlet port to the air flow passages.

Abstract: A Joule-Thomson cryogenic refrigeration system capable of achieving high temperature stabilities in the presence of varying temperature, atmospheric pressure, and heat load is provided. The Joule-Thomson cryogenic refrigeration system includes a demand-flow Joule-Thomson expansion valve disposed in a cryostat of the refrigeration system. The expansion valve has an adjustable orifice that controls the flow of compressed gas therethrough and induces cooling and partial liquefaction of the gas. A recuperative heat exchanger is disposed in the cryostat and coupled to the expansion valve. A thermostatically self-regulating mechanism is disposed in the cryostat and coupled to the J-T expansion valve. The thermostatically self-regulating mechanism automatically adjusts the cross-sectional area of the adjustable valve orifice in response to environmental temperature changes and changes in power dissipated at a cold head.

Abstract: Perforated plate heat exchangers and cryocoolers based on plates with extremely small, tubular holes are disclosed. The plates may have hole diameters down to the low micron size range and length-to-diameter ratios above unity and from 2 to 6 for typical applications. Such perforated plates function as tubes rather than screens and provide high efficiency, especially for compact cryocooler applications. The plates, which are made of a high thermal conductivity metal, and alternating spacers of low thermal conductivity material are disposed in an elongated stacked array of a large number of units such as 100. For use in a recuperative heat exchanger for a cryocooler employing the Linde-Hampson cycle, webs at the plate and spacer edges and a strip across the middle define two flow chambers, one for gas flow in each direction. One end of the array communicates with a high-pressure gas inlet for introducing gas in one chamber and a low-pressure gas outlet for removing gas from the other chamber.

Abstract: A two-stage Joule-Thomson cryostat (10) has a first-stage cryostat (12) with a helical-coil heat exchanger (14) and and isenthalpic gas expansion orifice (20) that discharges a mixture of cooled gas and cryogenic liquid into a liquid cryogen plenum (26). A second-stage cryostat (30) with a helical coil heat exchanger (32), wound to a larger diameter than the first-stage heat exchanger coil (14), is wound around and in thermal contact with the liquid cryogen plenum (26). This arrangement achieves a high degree of interstage heat transfer and cooling of the gas flowing in the second-stage heat exchanger coil (32) by the liquid cryogen in the first-stage liquid cryogen plenum (26). In operation, a gas flow management system (60), designed for rapid cooldown, initially passes a first gas of high specific refrigerating capacity through both stages (12 and 30).

Abstract: A cryogenic refrigeration system has a control system that controls the operation of the refrigeration system and provides status information to the operator of the refrigeration system. The cryogenic refrigeration system includes one or more heater and at least one Joule-Thomson valve. The heaters are used to control the recondensing capacity of the refrigeration system and to heat the at least one Joule-Thomson valve and other points to melt away contaminants that may freeze at such points. The control system controls operation of the heaters. The control system also automates an initialization routine that utilizes the heaters to prevent blockage of the valves, and cools the refrigeration system down to a desired temperature. In addition, the control system shuts down the refrigeration system if the status information it monitors exceed a safe range.

Abstract: An integral cryogenic refrigerator, or cryocooler, for cooling an electronic device to cryogenic temperatures. The cryocooler has a minimum number of moving parts. A lightweight flexure links a compressor piston to a coupler which is also connected to a regenerator via a lightweight vane. An electric motor with an offset shaft drives the coupler via a bearing through a circular path to impart properly timed motion to the compressor piston and regenerator. This arrangement minimizes the weight and number of moving parts, resulting in maximum efficiency and operating life. Vibration transmission is minimized by mounting the device to be cooled on an end cap having a raised castlated rim. A reusable access port allows the cryocooler to be readily recharged.

Abstract: Heat pump systems (principally FIG. 3; also FIGS. 5, 7 or 9) comprising, in circuit of fluid, an injected compressor 113, communicating a compressed gas discharge 137 to a condenser 100, communicating an at least partly liquid output 130 to an expansion valve 101, communicating therefrom 131 to a separator 110, communicating liquid therefrom 134 to a capillary tube 111, and communicating gas therefrom 132 to a control valve 112 that is responsive to ambient temperature; 111 communicating the liquid therefrom 135 to an evaporator 102, communicating gas therefrom 136 to an inlet of the injected compressor 113; the control valve 112 communicating gas therefrom 133 to an injection input of the injected compressor 113; and the expansive valve 101 being adjustable 176,171 responsive to the temperature of the gas communicating 136 from the evaporator 102 to the injected compressor 113. Where the fluid comprises a non-azeotropic refrigerant blend (NARB), the system (FIG. 5; also FIG.

Abstract: There is provided by this invention a method and an apparatus for cooling a heat load that is operable in zero gravity conditions and while in any orientation due to the design of the apparatus. The apparatus' components are also selected so as to comprise a lightweight refrigeration system. The apparatus utilizes direct contact between two fluids, a liquid coolant and a refrigerant, with widely different vapor pressures so that one fluid, the coolant, always remains a liquid in the system. The two fluids may be totally or partially soluble in one another or they may be totally insoluble in one another with the degree of solubility affecting the system's efficiency, but not its reliable operation. The refrigerant, which boils and condenses during the refrigeration cycle, is mixed with the coolant and condensed prior to the portion of the system's cycle in which the heat is rejected to a heat sink and is subsequently separated from the coolant.

Abstract: A pressurized flow of a refrigerant gas discharged from a gas compressor and which has compressor lubricating oil entrained as a mist therein, is subjected to an oil separation in a separating unit of a separator assembly wherein by impacting flow of the oil-containing gas against impact structure in the separating unit, oil is caused to separate from the gas with the oil falling to the bottom of the separating unit, post-impact flow of the refrigerant gas being in a torturous flow path in the separating unit which torturous flow produces further and additional oil separation from the gas. The gas ultimately, has outlet from the unit at an upper end thereof from whence the gas passes to a point of use, the separated oil passing from the unit through a return capillary tube conduit to the compressor.

Abstract: Cryogenic cooling apparatus comprising an inlet path through which refrigerant gas is caused to flow, a Joule-Thomson expansion nozzle which communicates with the inlet path and in which, in use, a proportion of the refrigerant gas is caused to liquefy and an outlet path communicating with the outlet of the expansion nozzle, the inlet path being in heat exchange relationship with the outlet path. An elongate valve needle cooperates with the outlet side of the expansion nozzle and together with the latter constitutes a valve. A sensor is disposed in the space on the outlet side of the expansion nozzle and is arranged progressively to close the valve as the amount of liquid refrigerant in contact with it increases. The valve needle defines a bypass passage which extends along its entire length and remains open at all times. The apparatus is accommodated within a container, to the outer surface of a portion of the wall of which a thermal load is connected.