Abstract: The present invention relates to the art of refrigeration and more particularly to a method of regulating the cooling process by controlling the oil pressure in a compressor. The system prevents the accumulation of the liquid refrigerant in the crankcase of the compressor and allows a compressor to continue to work without interruption.

Abstract: An evaporator for a refrigeration chiller includes a tube bundle in which at least a portion of the tubes of the tube bundle are immersed in a pool which include both liquid refrigerant and is lubricant. Liquid refrigerant and lubricant are deposited into the pool at a first pool location. Because of the vaporization of refrigerant that occurs within the pool, a pattern of flow is established and managed that causes the lubricant in the pool to migrate from the location of its deposit into the pool to a second pool location. An outlet is provided at the second pool location from which lubricant is drawn out of the evaporator.

Abstract: An accumulator-dehydrator for use in an air conditioning system having a delivery tube that has an unobstructed free end for drawing in vaporized refrigerant and an oil pickup tube for drawing in oil and liquid refrigerant into the hollow delivery tube. The hollow delivery tube includes a venturi portion, which creates the draw necessary to pull the oil and liquid refrigerant into the hollow delivery tube. An equalization hole is also provided to prevent a liquid slug from migrating to the compressor, thereby damaging the compressor.

Abstract: A lubricant-refrigerant composition contained within a compression refrigeration system is disclosed which comprises (A) at least one fluorine-containing hydrocarbon refrigerant containing 1 to 3 carbon atoms, further wherein fluorine is the only halogen in said fluorine-containing hydrocarbon with the proviso that 1,1,1,2-tetrafluoroethane is not the sole refrigerant; and (B) at least one lubricant comprising (1) a hydrocarbyl substituted arene, (2) a phosphate ester, (3) an organic ester of a carboxylic acid and an alcohol, (4) a perfluoropolyethylene, (5) an ether; (6) a polyether; (7) a polyalphaolefin; or (8) a mineral oil; wherein at a temperature of above −60° C. a phase separation occurs such that at least two phases are formed, said phases being a refrigerant rich phase and a lubricant rich phase, further wherein the lubricant rich phase resides below the refrigerant rich phase.

Abstract: Oil return from the evaporator to the compressor of a refrigeration chiller is accomplished by routing the suction piping that communicates between the chiller's evaporator and compressor to a location physically below the lubricant-rich pool at the bottom of the evaporator shell and by connecting the lubricant-rich pool to the compressor suction piping at a location where the suction piping is disposed physically below the pool.

Abstract: An integrated modular collector—heat exchanger unit for motor vehicle air conditioners and the like has a collector housing in which a collecting space and a heat exchanger unit are disposed. The heat exchanger unit includes two separate heat exchanger ducts which are in a thermal contact. One heat exchanger duct has a helical course and is part of a first flow duct which extends from a housing inlet to a housing outlet in the collector housing. The other heat exchanger duct is part of a second flow duct extending between the collecting space and a housing connection. This other heat exchanger duct also has a helical course, its coils in each case being in a thermal contact with at least one adjoining coil of the first of the first heat exchanger duct.

Abstract: The suction accumulator is pre-charged with oil that is contained ordinarily in accumulator body. This pre-charged oil amount is in addition to the amount of oil normally charged into compressor oil sump, and makes the total amount of oil charge greater. This increased oil helps improve compressor lubrication under boundary lubrication conditions due to liquid refrigerant. Without increasing the amount of oil in the oil sump of the compressor, the quality of the oil is improved with an accumulator with pre-charged oil. That is, additional oil is charged into the accumulator, and the oil return orifice is so located in elevation that a specified volume is contained below the orifice. The volume of the accumulator is increased by providing a side discharge from the accumulator to the suction inlet of the compressor and by extending the accumulator below the suction inlet. In reality though, the volume does not necessarily contain pure oil because oil almost always contains some refrigerant.

Abstract: A portion of the condensed liquid in a condenser is diverted to a generator where it supplies heat to boil off refrigerant from a refrigerant oil mixture and is thereby subcooled. The subcooled liquid is supplied to the motor for cooling. The boiling off of refrigerant in the generator results in an “oil rich” liquid which is supplied to the bearings, etc. for lubrication. One, or more, jet or ejector pumps are preferably used to supply the oil rich liquid to the lubrication distribution system.

Abstract: The suction feed pipe of an accumulator extends above the flow path through a baffle dividing the accumulator thereby permitting the storage of a larger amount of liquid in the accumulator. Where the accumulator has a portion located below the fluid connection going into the compressor, this portion can be used to store a charge of make-up oil to replace the oil distributed in the system during operation without initially overcharging the compressor or of compromising the compressor oil charge.

Abstract: Oil is returned from the evaporator to the oil sump in a refrigeration chiller by directing the lubricant-liquid refrigerant mixture found in the chiller evaporator into heat exchange contact with relatively hotter system lubricant as such lubricant flows from the oil sump to the location of its use in the chiller's compressor. The oil flowing from the sump to the compressor rejects sufficient heat to the lubricant-liquid refrigerant mixture to induce the percolation thereof, such percolation being sufficiently energetic to cause slugs of the lubricant-liquid refrigerant mixture to be delivered from the location of heat exchange into the chiller's lubricant sump thereby effecting the return of oil from the evaporator for re-use in the compressor.

Abstract: A cryogenic liquid heat exchanger system has a subatmospheric pressure reservoir, a tube, and an initial fluid ejector. The sub-atmospheric pressure reservoir has a vacuum exhaust. The tube extends through the reservoir. The initial fluid ejector has a suction chamber inlet that is functionally connected to the reservoir vacuum exhaust. The system may have a plurality of fluid ejectors connected to one or more exhausts either in series or parallel. The initial fluid ejector may receive one or more pressurized fluid streams, and the streams may be steam. A process for generating sub-atmospheric pressures in a cryogenic fluid heat exchanger reservoir includes the step of discharging an initial fluid stream into an initial fluid ejector having a suction chamber functionally connected to an exhaust of the reservoir. A process for generating sub-atmospheric pressures in a cryogenic fluid heat exchanger reservoir includes the step of using a fluid ejector to reduce the pressure in the reservoir.

Abstract: A system and method for cooling a first cryogenic liquid in a vessel comprises the steps of directing a second cryogenic into the first cryogenic fluid and releasing gas from the vessel. The first cryogenic fluid has a boiling point that is higher than the boiling point of the second cryogenic fluid. Directing the second cryogenic fluid into the first cryogenic fluid results in the second fluid cooling the first fluid and the second fluid vaporizing. The vaporized fluid is released as a gas from the vessel. The vessel may be a propellant tank for a space vehicle. The first and second cryogenic fluids are delivered from supplies located outside of the vehicle. The first cryogenic liquid may be oxygen and the second cryogenic liquid may be nitrogen, neon, or helium. In another aspect of the invention, the first cryogenic liquid may be hydrogen and the second cryogenic liquid may be helium.

Abstract: A method for densifying the LO2 propellant of a vehicle (10) includes providing a heat exchanger (16) including a chamber (22), and an isolated heater (24) and cooler (26) located within the chamber (22). The method further includes the step of pumping propellant (LO2) (with pump 14) from the vehicle (10) to the first port (24i) of the path of the heater (24), to thereby create a flow of propellant (LO2) through the heater (24) path, and from the second port (24o) of the path of the heater (24). In conjunction with the pumping, propellant (LO2) is coupled from the second port (24o) of the heater (24) back to the vehicle (10), to thereby establish a recirculating flow of propellant (LO2). The chamber (22) of the heat exchanger (16) is filled with at least sufficient cryogenic liquid (LN2) to cover at least a portion of the path of the cooler (26), and preferably the entirety of the path of the cooler (26).

Abstract: Slush is made from a liquid using slush making systems or according to slush making processes. A jacketed vessel of the processes and the systems has an interior wall that defines an interior space. The interior space comprises a top and a bottom. The interior space has an average overall cross-sectional area taken through a vertical axis extending generally between the top and the bottom. The interior space also has a collection portion having an average collection portion cross-sectional area taken through the vertical axis that is less than the average overall cross-sectional area. The liquid is placed into the interior space and the interior walls are cooled. Slush forms on the interior walls and migrates to the collection portion. The collection portion is located at the interior space bottom when the slush density is higher than the liquid density and the collection portion is located at the interior space top when slush density is less than the liquid density.

Abstract: A refrigeration system having compressors positioned higher than the dispersed evaporators requires multiple suction risers. To better ensure oil return to the compressors, only a single oil return riser is employed. This oil return riser is connected to one end of an oil collection main positioned near the lower portion of the suction risers. The oil collection main is connected by restricted oil drain conduits to the lower portions of the suction risers, thereby collecting the oil which failed to be conveyed to the top of the suction risers by their vapor velocity. The restrictions in the oil drain conduits ensure adequate vapor velocity within the oil collection main even with widely varying loads on the suction risers.

Abstract: A cryogenic propellant tank system and process for densifying cryogenic liquid propellant comprises a tank with a combined manifold, a combined manifold line, a pressurizing gas line, and a vent line. The combined manifold is located in the tank. The combined manifold line functionally connects the combined manifold to a chilling system. The pressurizing gas line and the vent line are also functionally connected to the combined manifold line. The tank may be disposed in a vehicle. The manifold is disposed proximate the top of the tank. The chilling system may be a heat exchanger/filling system. The process for filling the tank comprises the steps of charging the tank with cryogenic liquid propellant, venting gases in the tank, densifying the cryogenic liquid propellant, and pressurizing the tank. The tank is charged with the cryogenic liquid propellant such that the orifices in the combined manifold are submerged. The gases in the tank are vented through the combined manifold and out of the tank.

Abstract: An enhanced motor cooling and lubrication system for a liquid chiller includes a liquid refrigerant cooled compressor drive motor, wherein the refrigerant used to cool the drive motor is returned to the chiller's condenser, and apparatus to better facilitate the return of oil carried to the compressor entrained in the suction gas flow stream back to the chiller's oil supply tank.

Abstract: A cryogen recondensing magnetic resonance imager superconducting magnet utilizing a rare earth displacement material cryocooler with a superconducting sleeve surrounding a portion of the circumference of the cold end of the cryocooler to provide superconducting current flow of currents induced by movement of the rare earth displacer to generate opposing magnetic fields which shield the imaging region of the superconducting magnet from magnetic interference generated by movement of the cryocooler rare earth displacer.

Abstract: An accumulator is capable of preventing an excessive enlargement of the flow rate of a liquid refrigerant which is discharged from the accumulator, reducing the quantity of refrigerating machine oil which is accumulated in the accumulator, and maintaining a required quantity of refrigerating machine oil in a compressor. Liquid and a gas which circulate in a refrigerating and air-conditioning circuit are introduced into a first space by a suction pipe, and the gas refrigerant is discharged to a refrigerating and air-conditioning circuit through a gas passage pipe, a second space and a discharge pipe 5. A liquid-level maintaining mechanism prevents a rise in the height of the accumulated liquid introduced into the first space. When the height has been made to be not lower than a predetermined height, a gas communication mechanism moves liquid in the first space from the first space to the second space.

Abstract: A pressure control system for the cryogen pressure vessel of a helium cooled superconducting magnet assembly including a helium gas recondenser to return liquid helium to the helium supply including a temperature sensor proximate to the recondenser to provide a control signal for maintaining a preselected temperature of said recondenser in order to maintain a preselected pressure within said helium vessel above the pressure outside the vessel and further including an indication of the thermal conductance across the interface between the recondenser and the cryocooler which cools the recondenser.

Abstract: There is disclosed herein an accumulator for an air conditioning system. The accumulator includes a sump for collecting oil to be provided to the air conditioning compressor. There is also disclosed an outlet tube in the accumulator, the tube having a flange opening and a necked-down portion a predetermined distance from the flange opening.

Abstract: An oil separator for an evaporator in a cooling system is installed between a capillary tube and the evaporator for separating oil from the refrigerant flowing into the evaporator. The oil separator comprises an inflow member connected to the capillary tube, for receiving the oil-containing refrigerant therefrom. A refrigerant outflow member is connected between the inflow member and an inlet of the evaporator, for conducting the refrigerant upward to the inlet of the evaporator. An oil outflow member is disposed between the inflow member and an outlet of the evaporator, for conducting the oil downward to an outlet of the evaporator. The oil separator prevents oil from flowing into the evaporator, thereby preventing accumulation of the oil inside the evaporator which could reduce the amount of oil disposed inside a compressor of the cooling system.

Abstract: In an accumulator constituting a refrigerating cycle apparatus, a high liquid-level auxiliary pipe (14a) and a low liquid-level auxiliary pipe (14b), which act as oil recovery pipes, and each of which is provided with a plurality of oil recovery holes (10a), are attached to a discharge pipe (12) in positions so as to be different vertically from each other, so that lubricating oil can be surely recovered through the oil recovery holes.

Abstract: An NMR measuring device contains an NMR probe head (10a) having an NMR receiver coil (11), and the probe head can be supplied via a cryogenically insulated transfer conduit (9) with coolant from a cooling device (1a). The cooling device comprises a cryo-cooler (2) having a first cooling stage (4) with a first stage exchanger (12) and a second cooling stage (3) having a second stage exchanger (8). A pump (6) transports coolant in the cooling circuit. The NMR probe head (10a), in addition to the NMR receiver coils (11), has preamplifiers (21) for amplifying the received NMR signals and an additional cryogenically insulated transfer conduit (20) is inserted between the cooling device (1a) and the NMR probe head (10a) by means of which, the preamplifiers (21) and/or the components in contact with the preamplifiers (21) can be supplied with a flow of coolant at a higher temperature than that used for cooling the NMR receiver coils (11).

Abstract: In a multi story air conditioning system having elevated compressors and varying loads, a suction line oil return arrangement comprising dual parallel suction risers having a pressure relief valve positioned in one to ensure a minimum pressure drop for oil return in the other.

Abstract: The lowest metering port in the suction feed pipe of an accumulator is located such that a residual liquid storage volume is created which is at least 20% of the total volume available for liquid storage without overflowing into the suction feed pipe.

Abstract: A vapor compression refrigeration system for cooling a liquid in which there is a spray dispenser for distributing liquid refrigerant over the tubes in a shell-and-tube type evaporator. The differential pressure in the refrigerant flow loop across the evaporator is the sole means of producing a flow through the spray dispenser. The evaporator is operated as a hybrid falling film heat exchanger, that is, in a semi-flooded condition. The lower portion of the evaporator shell is flooded with liquid refrigerant to wet the lower tubes in the tube bundle while the tubes in the upper portion are wetted only by refrigerant spray from the spray dispenser. The system is operated in a steady state condition whereby at least twenty-five percent (25%) of the tubes in the evaporator operate in a flooded heat transfer mode. The system allows a reduction in the amount of refrigerant charge in the system while at the same time avoiding the use of a recirculating system and pump.

Abstract: In an accumulator, an oil collecting pipe is held in a sealed vessel with the lower end thereof closed, the pipe has a plurality of oil collecting apertures spaced in a vertical direction and a communication port for communicating with a discharge pipe. The communication port is disposed in the vicinity of the lowermost oil collecting aperture or to the downstream side of the aperture. Therefore, excessive liquid refrigerant flow from the accumulator is prevented even if a large amount of the liquid refrigerant resides in the sealed vessel.

Abstract: A system and method for the delivery of cryogenic fluid, more particularly a cryogenic fuel, such as, for example, but not limited to an liquified natural gas (LNG), to a cryogenic fluid using source, and more particularly an LNG fuel source, and even more particularly an LNG fuel-operated engine. The system includes a source of a cryogenic fluid, more particularly an underground tank and with a liquid level within the underground tank source. The system includes a delivery pump to deliver cryogenic fluid from the underground tank source, to a cryogenic using source, typically an LNG fuel source above the underground tank source, with the pump located below the liquid level of the cryogenic fluid in the cryogenic fluid fuel tank.

Abstract: A helium cooled superconducting magnet assembly with helium gas recondensing apparatus to return liquid helium to the helium supply in the helium vessel in which the recondensing apparatus positioned within the space between the vacuum vessel and surrounding vacuum vessel in thermal contact with a cryocooler within a fixed cryocooler sleeve in the vacuum vessel with the cryocooler positioned to minimize magnetic disturbances to the magnet assembly magnetic field and the recondenser connected through thin corrugated steel tubing to the helium vessel with the tubing sized to provide thermal and vibration isolation of the helium vessel.

Abstract: Methods and apparatus for (a) increasing expansion tank "acceptance" (defined herein as working fluid storage capacity); and (b) adjusting the rate of pressure variations within a prespecified range in precharged fluid storage systems (for example, holding pressure down below a prespecified threshold value for a given volume of acceptance, stored water temperature level, etc.). A "volatile" fluid (defined herein as a fluid having a boiling point within the predetermined pressure and temperature operating ranges for a given system), is used at least in part as the expansion fluid in an expansion tank included in a fluid storage system.

Abstract: An accumulator includes an axial lower region for the accumulation of liquid refrigerant and an axial upper region for the accumulation of vapor refrigerant. A desiccant bag is disposed within the accumulator for removing moisture in the refrigerant. A U or J-shaped return tube in the accumulator has a lower most portion close to the lower end wall of the accumulator. An oil inlet tube and screen assembly is connected to the return tube at the lower most portion of the return tube. A first end of the oil inlet tube is received within an orifice formed in the bottom of the return tube, while the second end of the oil inlet tube extends axially downwardly toward the lower end wall of the accumulator. A screen assembly surrounds the oil inlet tube to prevent particles from entering the return conduit. The oil inlet tube draws oil practically down to the lower end wall of the accumulator for return to the refrigeration system.

Abstract: A refrigeration system employing a screw compressor and a falling film evaporator makes use of high-side pressure to drive lubricant, which escapes the compressor and collects as a lubricant-rich mixture of lubricant and refrigerant in the system evaporator, back to the compressor. The mixture is cyclically exposed to high-side pressure for a period of time which (i) varies in accordance with the difference between a sensed condenser-related pressure and a sensed evaporator-related pressure and (ii) is calculated to maintain a predetermined oil concentration in the lubricant-rich mixture in the evaporator so as to minimize the parasitic losses to system efficiency associated with the oil return process.

Abstract: A geothermal heating and/or cooling system includes one or more of a plurality of features that enhance the efficiency of the system. Preferably, the system includes a subterranean heat exchanger having tubes disposed against a conductive sheet. The system also preferably includes a reservoir vessel for holding a supply of heat transfer fluid in a liquid phase. Also, the system preferably includes heat exchange means for exchanging heat between the heat transfer fluid and the outdoor air. In addition, the system preferably has an automatically adjusting cooling expansion valve controlled by a sensor disposed to detect the pressure or temperature of heat transfer fluid exiting an indoor air handler in a cooling mode, the system also preferably has an automatically adjusting heating expansion valve controlled by a sensor that is preferably located so as to detect the temperature or pressure of heat transfer fluid flowing from the subterranean heat exchanger to a gas compressor.

Abstract: In a refrigerating cycle using a refrigerant containing hydrofluorocarbon as a main component, of a refrigerant pipe arrangement constituting the refrigerating cycle, a refrigerant pipe extending upward from a lower side to an upper side is made to have an inner diameter not larger than a value which makes the flow rate of the refrigerant be not smaller than a zero penetration flow rate. It is possible to obtain a refrigerating cycle superior in oil returning to a compressor and hence high in reliability, even in the case of using refrigerator oil having no compatibility with a refrigerant containing hydrofluorocarbon as a main component.

Abstract: A cryogen recondensing system magnetic resonance imager superconducting magnet and a cryogen recondensing system with a rare earth displacement material cryocooler and superconductive lead bismuth magnetic sleeve provides superconducting current flow of currents induced by movement of the rare earth displacer which generate opposing magnetic fields to shield the superconducting magnet from the magnetic interference of the cryocooler rare earth displacer. Strips of high conductivity wave-shaped aluminum or sapphire rods may be embedded in the surface of the sleeve to lower the thermal resistance of the superconducting shield to enable it to quickly reach superconducting temperature.

Abstract: A refrigerant circuit suction accumulator has an inner copper U-tube with open inlet and outlet ends, a small oil inlet metering orifice formed in the closed tube end, and a threaded connection stud secured to the closed tube end. Formed on an inlet end portion of the U-tube is an integral deflector structure positioned between refrigerant outlet and inlet openings in the tube side wall. The U-tube legs extend through openings in a generally disc-shaped wire mesh filter element adjacent the closed tube end. The U-tube and filter element are disposed within a unitary tubular outer shell formed from a length of seamless copper tubing. In forming the assembly, one end of the outer copper tube is spun closed and a spaced pair of holes are formed therein.

Abstract: There is disclosed herein an accumulator for an automotive air conditioning system. The accumulator includes a sump for collecting oil to be provided to the air conditioning compressor. There is also disclosed an outlet tube in the accumulator, the tube having a flange opening and a necked-down portion a predetermined distance from the flange opening.

Abstract: Super cooling the cryogenic liquid propellant in a vehicle propellant tank densities the propellant allowing the vehicle propellant tank to carry more fuel in the same volume tank while lowering the vapor pressure and thus the tank operating pressure. Lowering the tank operating pressure reduces the stress and therefore allows the walls of the tank to be thinner. Both the smaller tank volume and thinner tank wall results in an overall smaller and lighter vehicle with increased payload capability. The cryogenic propellant can be supercooled well below the normal boiling point temperature level by transporting the liquid propellant from the vehicle tanks to a ground based cooling unit which utilizes a combination of heat exchanger and compressor. The compressor lowers the coolant fluid bath pressure resulting in a low temperature boiling liquid which is subsequently used to cool the recirculating liquid. The cooled propellant is then returned to the vehicle propellant tank.

Abstract: A helium cooled superconducting magnet assembly including helium gas recondensing apparatus to return liquid helium to the helium supply in the helium vessel includes a recondenser positioned in the helium vessel above the helium supply connected to a cryocooler in a dual-sleeve assembly enabling breaking of thermal joints with thermal isolation from the helium for servicing of the cryocooler during superconducting operation of the magnet assembly, and providing recondensing of helium gas to fall by gravity back to the helium supply.

Abstract: A compression type refrigerator has an evaporator, a condenser, a compressor for compressing a refrigerant gas, an oil tank for storing a lubricating oil, and an oil supply device connected to the oil tank for supplying the lubricating oil to the compressor by an oil pump. The discharge side of the oil pump is connected to the oil tank through an ejector. A pipe connected at one end to the evaporator to take out a refrigerant liquid is connected at the other end to a negative pressure generation portion of the ejector.

Abstract: A MRI cryostat, which contains a superconducting magnet operating in a bath of liquid helium, reduces the boil-off rate of helium by intercepting most of the heat in-leakage by means of a throttle cycle (TC) refrigerator operating at a low side temperature of about 90K. The main heat exchanger for the throttle cycle refrigerator is located within or immediately adjacent to the cryostat housing and delivers cold liquid to a cold heat exchanger that is in thermal contact with an outer radiation shield, support struts, neck tube and electrical leads inside the cryostat. Heat is intercepted by the outer shield from essentially all paths between a 300K ambient and a 4K load temperature, which temperature results from liquid helium boil-off to atmosphere. A second, inner radiation shield at 35K is cooled by gaseous helium that boils from the liquid helium bath. There are no moving parts of the refrigeration system in the cryostat. Thus, vibration, noise and disturbance of the magnetic field are reduced.

Abstract: A cryogen delivery apparatus for delivering cryogen in a saturated state includes a vessel to contain the cryogen in liquid and vapor phases. The vessel has a headspace region and a heat exchanger located within the headspace region for indirectly exchanging heat between the vapor located within the headspace region and a liquid stream composed of the liquid phase of the cryogen. In case the cryogen is introduced into the vessel as a subcooled liquid, the vapor will condense into the liquid phase and the subcooled liquid will be converted into a saturated liquid. The saturated liquid will then be discharged from a liquid outlet connected to the heat exchanger. In the event the liquid enters the vessel as two-phase flow, the vessel will act as a phase separator. A branched supply line is provided having a liquid inlet branch connected to a bottom liquid inlet of the vessel so that a supply stream composed of the cryogen flows into the vessel.

Abstract: A refrigerant circuit suction accumulator has an inner copper U-tube with open inlet and outlet ends, a small oil inlet metering orifice formed in the closed tube end, and a threaded connection stud secured to the closed tube end. Formed on an inlet end portion of the U-tube is an integral deflector structure positioned between refrigerant outlet and inlet openings in the tube side wall. The U-tube legs extend through openings in a generally disc-shaped wire mesh filter element adjacent the closed tube end. The U-tube and filter element are disposed within a unitary tubular outer shell formed from a length of seamless copper tubing. In forming the assembly, one end of the outer copper tube is spun closed and a spaced pair of holes are formed therein.

Abstract: Compression refrigeration apparatus for removing heat from a heat load using a falling film evaporator, operated with an azeotropic refrigerant and utilizing a vapor-liquid separator, preferably inside the evaporator vessel. In one embodiment, two types of heat exchange surfaces are utilized--one for maximizing the axial distribution of refrigerant film on a heat exchange surface, the other for encouraging liquid refrigerant in contact with a heat exchange surface to boil and evaporate. The apparatus allows for efficient recovery of lubricant deposited in the evaporator without redistributing the lubricant within the evaporator.

Abstract: Process for the temperature stratification-free storage of a cryogenic liquid in a thermally insulated tank under gravitation conditions or under gravitation and movement conditions, which generate a liquid volume with a clearly limited, unmoving or only moderately moving liquid level as well as with a gas space located above it in the storage volume of the tank. Liquid is pumped off from the area near the bottom of the tank continuously or at time intervals, it is fed into the area of the gas space, and it is directed vertically or at an acute angle toward the liquid level there in the form of at least one high-energy jet.

Abstract: A refrigeration system includes a dewar and a refrigerator/liquefier which meets the variable demands of a superconducting magnet within the dewar. The system is sized to meet average loads over a defined duty cycle, and is variably operable to meed demands. In the preferred embodiment, a first supply of fluid circulates through a "condenser" element positioned in a dewar ullage to liquefy a separate supply of fluid in the dewar, and to refrigerate a pulsed cryogenic load therein, such as a superconducting magnet. A portion of the first supply of fluid may be diverted to refrigerate a second pulsed cryogenic load, such as magnet current leads permanently connected to the magnet. The dewar includes a cold gas vapor storage chamber separate from the dewar ullage, and the chamber is preferably located within the inner core of a solenoid superconducting magnet for compact and thermally efficient design. Responsive, independent adjustment of refrigeration to pulsed cryogenic loads is made possible.

Abstract: A compression type refrigerator has an evaporator, a condenser, a compressor for compressing a refrigerant gas, an oil tank for storing a lubricating oil, and an oil supply device connected to the oil tank for supplying the lubricating oil to the compressor by an oil pump. The discharge side of the oil pump is connected to the oil tank through an ejector. A pipe connected at one end to the evaporator to remove a refrigerant liquid, is connected at the other end to a negative pressure generation portion of the ejector.

Abstract: Cryogenic fluid piston pump functions as stationary dispensing pump, mobile vehicle fuel pump etc., and can pump vapour and liquid efficiently even at negative feed pressures, thus permitting pump location outside a liquid container. Piston inducts fluid by removing vapour from liquid in an inlet conduit faster than the liquid therein can vaporize by absorbing heat, and moves at essentially constant velocity throughout an induction stroke to generate an essentially steady state induction flow with negligible restriction of flow through an inlet port. Stroke displacement volume is at least two orders of magnitude greater than residual or dead volume remaining in cylinder during stroke changeover, and is greater than volume of inlet conduit. Cryogenic tank has a liquid compartment, a vapour compartment, and inlet and overflow conduits. Inlet conduit receives liquid from dispensing pump and widely disperses liquid into liquid tank to contact and condense vapour.

Abstract: A refrigeration system includes a dewar and a refrigerator/liquefier which meets the variable demands of a superconducting magnet within the dewar. The system is sized to meet average loads over a defined duty cycle, and is variably operable to meed demands. In the preferred embodiment, a first supply of fluid circulates through a "condenser" element positioned in a dewar ullage to liquefy a separate supply of fluid in the dewar, and to refrigerate a pulsed cryogenic load therein, such as a superconducting magnet. A portion of the first supply of fluid may be diverted to refrigerate a second pulsed cryogenic load, such as magnet current leads permanently connected to the magnet. The dewar includes a cold gas vapor storage chamber separate from the dewar ullage, and the chamber is preferably located within the inner core of a solenoid superconducting magnet for compact and thermally efficient design. Responsive, independent adjustment of refrigeration to pulsed cryogenic loads is made possible.