Abstract: A liquefied gas unloading and deep evacuation system may more quickly, more efficiently and more completely unload liquefied gases from transport tanks, such as rail cars, into stationary storage tanks or into truck tanks. The system may utilize a two stage compressor, an electric motor, a variable frequency drive, a four way valve, a three way valve, a two way valve, a programmable logic controller based control system and pressure and temperature transmitters. The valving enables deep evacuation of the transport or supply tank to more completely empty the transport tank. The programmable logic controller and variable speed drive may be used to variably control the speed of the two stage compressor so that the system may be running as fast as possible during changes in ambient temperature and/or different stages of offloading the liquefied gases without exceeding the compressor's horsepower limit.

Abstract: A system and a method for dispensing a liquefied fuel (e.g., hydrogen) are provided. The system includes a cryotank for storing a liquefied fuel, a pump insertable into the cryotank, and a switching valve. The pump has a piston, an intake port, and an isolation valve configured to supply the liquefied fuel to the intake port. The switching valve is controlled to flow the vapor from the pump and the liquefied fuel contacting a backside of the piston to the intake port of the pump. At least one block valve is also connected with the cryotank and the pump. At least one of the switching valve, the at least one block valve, and the isolation valve can be controlled to operate the system in one of three working modes including a pressure increase mode, a pressure maintaining mode, and a pressure decrease mode.

Abstract: A cryopump includes a cryocooler which includes a high-temperature cooling stage and a low-temperature cooling stage, a radiation shield which is thermally coupled to the high-temperature cooling stage and axially extends in a tubular shape from a cryopump intake port, a low-temperature cryopanel section which is thermally coupled to the low-temperature cooling stage, is surrounded by the radiation shield, and includes axially arranged cryopanels including a top cryopanel disposed closest to the cryopump intake port, and a top cryopanel accommodation cryopanel which is thermally coupled to the high-temperature cooling stage and is disposed in the cryopump intake port to form a top cryopanel accommodation compartment.

Abstract: In a cryopump, a primary cryopumping array having adsorbent and cooled by a second refrigerator stage extends along radiation shield sides. That array is shielded by a condensing cryopumping array that extends along the primary cryopumping array. The primary cryopumping array may be a cylinder with adsorbent on an inwardly facing surface, and the condensing cryopumping array may comprise an array of baffles having surfaces facing the frontal opening. A raised surface such as a conical surface at the base of the radiation shield redirects molecules received from the frontal opening toward the primary cryopumping array. The refrigerator cold finger may extend tangentially relative to the radiation shield or connect to the base of the radiation shield.

Abstract: A heat insulating vessel for a low temperature liquefied gas pump, which includes an inner tank configured to accommodate low temperature liquefied gas, an outer tank provided externally around the inner tank, and a low temperature liquefied gas pump disposed inside the inner tank. The outer tank has an outer tank upper part that is an upper end portion thereof, and an outer tank body other than the outer tank upper part. A lid structure having a heat-insulated structure detachably fitted into an upper part of the inner tank. The pump is fixed to the lid structure, and a suction pipe and a discharge pipe are insertedly fixed to the lid structure. A vacuum insulating layer is provided between the inner tank and the outer tank. With this heat insulating vessel for the low temperature liquefied gas pump, adiabaticity of the lid structure and maintainability of the pump are increased.

Abstract: Systems and methods that facilitate forming and maintaining FRCs with superior stability as well as particle, energy and flux confinement and, more particularly, systems and methods that facilitate forming and maintaining FRCs with elevated system energies and improved sustainment utilizing multi-scaled capture type vacuum pumping.

Abstract: The pump device includes: a pump body which transfers a transfer fluid; a drive unit which drives the pump body; an operating unit which sets an operation of the drive unit; and a joint mechanism which attaches the operating unit to the drive unit. The drive unit includes a casing. The operating unit includes a user-accessible operating surface. The joint mechanism is attached to a wall surface of the casing so as to be rotationally operable about a first axis perpendicular to the wall surface and supports the operating unit such that the operating surface crosses a second axis perpendicular to the first axis and follows along an outer surface of the casing.

Abstract: A cryopump includes: a first-stage target temperature selection unit which includes a normal target temperature for a normal mode of maintaining each of a first stage cryopanel and a second stage cryopanel at an extremely low temperature region, and a cool-down target temperature lower than the normal target temperature, for a cool-down mode of cooling each of the first stage cryopanel and the second stage cryopanel from room temperature to the extremely low temperature region, and selects the normal target temperature as a first-stage target temperature in a case where a current operation mode is the normal mode, and at least temporarily selects the cool-down target temperature as the first-stage target temperature in a case where the current operation mode is the cool-down mode; and a first-stage temperature control unit which controls a first-stage cryopanel temperature according to the selected first-stage target temperature.

Abstract: A refrigerator system or cryopump includes a first refrigerator having at least first and second stages, and a second refrigerator. A thermal coupling between the first stage of the first refrigerator and a cold end of the second refrigerator is restricted to maintain a temperature difference between the cold end of the second refrigerator and the first stage of the first refrigerator. The refrigerator system or cryopump also includes a radiation shield in thermal contact with the cold end of the second refrigerator, and a condensing surface, spaced from and surrounded by the radiation shield, and in thermal contact with a second stage, e.g., coldest stage, of the first refrigerator. The restricted thermal coupling can be configured to balance the cooling load on the two refrigerators.

Abstract: The present invention relates to a cryogenic heating system including a plurality of stages to provide accurate temperature control. The system can be used to provide non-contact heating and cooling of a test sample by use of an inert fluid. Accurate temperature control can be maintained, e.g., by use of controllers to provide temperature feedback control.

Abstract: A cryopump comprises a refrigerator, a condensing array cooled by the refrigerator, a radiation shield surrounding the condensing array and cooled by the refrigerator. The radiation shield has a frontal opening covered by a frontal array that is also cooled by the refrigerator. The frontal array comprises louvers across an otherwise substantially open center region of the frontal opening and an orifice plate across an outer region of the frontal opening. The hybrid frontal array allows for pumping speeds approximating those of a louver frontal array but with flow control comparable to an orifice plate.

Abstract: A damping assembly for a valve is provided. The valve is configured to move between an open position and a close position. The valve includes a valve element and a valve stem disposed within a head. The damping assembly includes a damping chamber defined within the head. The damping assembly defines a sidewall. The damping assembly also includes a collar configured to receive the valve stem. The collar includes a collar stem. The collar also includes a collar head having an outer diameter. The collar head includes a side surface. The damping assembly includes a liquid passageway. The liquid passageway is being defined by a radial clearance between the side surface of the collar head and the sidewall of the damping chamber. The liquid passageway is configured to control a flow of a liquid as the valve moves between the open position and the closed position.

Abstract: A cryopump includes a cryocooler which includes a first cooling stage, a second cooling stage having a tip stage surface, and a cryocooler structure portion which extends in an axial direction from the first cooling stage to the second cooling stage, a radiation shield which is thermally coupled to the first cooling stage and includes a shield front end which defines a shield main opening and a shield bottom portion having a cryocooler insertion hole which receives the cryocooler structure portion such that the tip stage surface faces the shield main opening, a cap member which surrounds the tip stage surface in a non-contact manner and is thermally coupled to the first cooling stage, and a second stage cryopanel which is disposed between the cap member and the first cooling stage in the axial direction and is thermally coupled to the second cooling stage.

Abstract: A method and device for purifying a process gas mixture, such as a cryogen gas, in which impurity components of the mixture are removed by de-sublimation via cryo-condensation. The gas mixture is cooled to a temperature well below the condensation temperature of the impurities, by direct exchange of the gas mixture with a cooling source disposed in a first region of the device. The de-sublimated or frozen impurities collect about the cooling region surfaces, and ultimately transferred to a portion of the device defining an impurities storage region. The output-purified gas is transferred from the impurities storage region, is optionally passed through a first micrometer sized filter, through a counter-flow heat exchanger, and ultimately up to an output port at room temperature. A method of purging the collected impurities and regenerating the device is also disclosed.

Abstract: A method of operating a cryopump includes: cooling a cryopanel from an initial temperature higher than a cryogenic temperature for a vacuum pumping operation to the cryogenic temperature by using a refrigerator; and after the cooling, initiating the vacuum pumping operation, in which the cooling includes providing a cooling relief effect selectively to a high-temperature stage of the refrigerator.

Abstract: A method of regenerating a cryopump includes: supplying a purge gas to a cryopump in order to heat a cryopanel to a first temperature zone higher than the melting point of water; suspending supply of the purge gas to the cryopump while a cryopanel temperature is in the first temperature zone, and heating the cryopanel from the first temperature zone to a second temperature zone higher than a purge gas temperature.

Abstract: A cryopump includes an adsorption cryopanel including a front surface configured to receive incidence of a non-condensable gas and a back surface having an adsorption region of the non-condensable gas, and a reflection cryopanel including a reflection surface of the non-condensable gas facing the back surface. The adsorption cryopanel may have a multitude of through holes penetrating from the front surface to the back surface. The adsorption cryopanel has a passage probability of the non-condensable gas selected from a range of 10% to 70%.

Abstract: A cryopump includes a radiation shield, a top cryopanel, and a bottom cryopanel. The radiation shield includes a shield main slit that communicates a shield outside gap into a shield cavity. The top cryopanel includes a top cryopanel outer circumferential end located axially above the shield main slit. The bottom cryopanel includes a bottom cryopanel outer circumferential end located axially below the shield main slit. An annular vacant space is formed between the top cryopanel outer circumferential end and the bottom cryopanel outer circumferential end and the top cryopanel outer circumferential end is directly opposed to the bottom cryopanel outer circumferential end with the annular vacant space interposed therebetween.

Abstract: Actuator devices useable to change orientation of one or more vanes, including an actuator rod and an actuator device body configured to allow the actuator rod to move along the axis inside the actuator device body, and having an inlet flange configured to allow a third fluid to enter a space between the actuator device body and the actuator rod, and an outlet flange configured to allow the third fluid to exit the actuator device body. Besides providing a fluid seal between the first fluid and the second fluid, the third fluid may also heat the actuator rod thereby preventing ice formation.

Abstract: A method of regenerating a cryopump includes a first discharging process that includes alternately evacuating a cryopump housing and supplying a purge gas in a first pressure range, and a second discharging process that includes evacuating the cryopump housing to a low pressure region below the first pressure range. The second discharging process includes making a determination at least once in the low pressure range as to whether the second discharging process should be terminated, and supplying the purge gas to the cryopump housing prior to a first-time determination as to whether the second discharging process should be terminated.

Abstract: A cryopump includes: a cryopanel assembly including a plurality of cryopanels each having an adsorption area on both surfaces thereof; a radiation shield forming a gas receiving space that surrounds the cryopanel assembly; and a radiation cover disposed in a cryopump inlet. The radiation cover includes a main plate located at a position in the cryopanel inlet that corresponds to the cryopanel assembly and a louver portion located at a position in the cryopanel inlet that corresponds to the gas receiving space. The radiation cover may not include the louver portion.

Abstract: A cryopump includes: a radiation shield that includes a shield front end that defines a shield opening, a shield bottom portion, and a shield side portion that extends between the shield front end and the shield bottom portion; and a cryopanel assembly that is cooled to a lower temperature than that of the radiation shield. The cryopanel assembly includes a first panel arrangement including a plurality of first adsorption panels and a plurality of second panel arrangements each including a plurality of second adsorption panels. The first panel arrangement forms a multitude of adsorption sections arranged in a lattice-shaped pattern in cooperation with the plurality of second panel arrangements, each of the adsorption sections being exposed to the shield side portion.

Abstract: A cryopump system includes: a plurality of cryopumps connected to a common roughing pump in a rough line and provided with a plurality of rough valves in the rough line, respectively; and a controller configured to control each of the rough valves for regenerating a corresponding one of the plurality of cryopumps. A delay time is set between closing of an open one of the plurality of rough valves and opening of a closed one of the plurality of rough valves. The controller applies the delay time uniformly upon closing of each of the rough valves.

Abstract: A cryopump includes a nested array of cryopanels. A hydrogen molecule incident into a clearance in the nested array of cryopanels is reflected by a cryopanel. The reflected hydrogen molecule is adsorbed by another cryopanel. Each of the cryopanels may have an inverted frustum shape.

Abstract: An apparatus for achieving a cryogenic temperature in a movable system, includes a rotating table, a vacuum chamber which is fixed on the rotating table, a cryogen-free refrigerator which has a cooling section inside the vacuum chamber, an inner cylinder which is fixed to a bottom of the rotating table, an outer cylinder which stores the inner cylinder such that the inner cylinder is rotatable and includes an outward and return gas port which is provided to be continuous with gas passages, a compressor which circulates gas to the cryogen-free refrigerator through the outward and return gas passages, and a rotary joint for wiring which is fixed to the inner cylinder and rotatably conducts electricity, wherein a piece of internal wiring is led through a through-hole and a hole, and electricity is supplied to a piece of equipment on the rotating table through the piece of internal wiring.

Abstract: The invention relates to a method for realizing a vacuum in at least one vacuum chamber. The method comprises providing an arrangement comprising a plurality of vacuum chambers, wherein each vacuum chamber is connected to a shared vacuum system. The shared vacuum system comprises a plurality of turbo molecular pumps, at least one common fore pump, and a piping system comprising one or more pipes for connecting the at least one common fore pump to each of the plurality of turbo molecular pumps. Each turbo molecular pump is separately connected to a corresponding vacuum chamber. The piping system further comprises flow regulators for controlling a flow within the piping system. The method further comprises selecting at least one vacuum chamber for pump-down, and separately pumping down the at least one selected vacuum chamber by means of the shared vacuum system.

Abstract: A cold trap is provided with a cold panel provided in a pumping path such that the panel is exposed, a refrigerator thermally coupled to the cold panel and operative to cool the cold panel; and a controller configured, in a regeneration process for evaporating a gas frozen on the surface of the cold panel and discharging the gas outside using the vacuum pump, to control the refrigerator so as to raise the temperature of the cold panel to a temperature exceeding a non-liquefaction temperature range and to adjust a pressure in the pumping path at the temperature so that the gas frozen on the surface of the cold panel is evaporated without being melted, the non-liquefaction temperature range being a range in which it is guaranteed that a gas frozen on the surface of the cold trap is evaporated without being melted.

Abstract: The cryogenic fluid generator includes at least one pump assembly having an actuator mounted to a container assembly. A pump assembly housing includes a longitudinal positioning opening and a pressurization cavity at a distal end terminating with a pump assembly outlet. An internal check valve assembly includes a shaft positioned within an opening of the pump assembly housing that extends into the pressurization cavity. The shaft is attached to the actuator and includes a longitudinal guidance slot; a fluid passageway; and, an internal sealing surface. A positioning bar assembly is positioned within the guidance slot. A connecting rod is securely connected at a first end to the positioning bar assembly, the connecting rod being positioned within the fluid passageway and terminating with a flow inhibiting element. A seal is positioned between the pump assembly housing and the check valve to provide a closure for the pressurization cavity.

Abstract: The invention relates to a method of realizing a vacuum in a vacuum chamber. The vacuum chamber is connected to a pumping system shared by a plurality of vacuum chambers. The method includes separately pumping down each vacuum chamber. The invention further relates to n arrangement of a plurality of vacuum chambers connected to a pumping system. In this arrangement, the pumping system is arranged for pumping down each vacuum chamber separately.

Abstract: A cryopump and a regenerating method of the cryopump whereby temperatures of a first stage and a second stage can be securely increased to target temperatures and time required for regenerating can be shortened are provided. At the time of regenerating, the temperature of the second stage cooling stage is controlled based on the temperature detected by the second temperature detection part. In the case where the temperature of the first stage cooling stage reaches the limiting temperature, namely critical temperature, of the first stage displacer, the rotation in the reverse direction of the reversible motor is controlled or stopped and thereby the regenerating process is stopped for a while.

Abstract: A storage method of a cryopump is provided, the storage method including: closing, with a pump cover, a pump inlet in the cryopump for receiving gases to be pumped by the cryopump; and reducing a pressure in the cryopump through a fluid channel for communicating an interior of the cryopump to an exterior of the cryopump. A start-up method of a cryopump is also provided, the start-up method including releasing a negative pressure in the cryopump by removing a closing member from a cover main body of a pump cover mounted to the cryopump.

Abstract: A cryopump includes a radiation shield provided with a main inlet at one end thereof and a sub-inlet in a side thereof; and a cryopanel assembly cooled to a temperature lower than that of the radiation shield. The cryopanel assembly includes an upper structure having at least one cryopanel and a lower structure having at least one cryopanel. The upper and lower structures are arranged inside the radiation shield along a direction away from the main inlet. A frost accommodating space connected to the sub-inlet may be arranged between the upper and lower structures such that an amount of captured gas on an upper end cryopanel of the lower structure is greater than an amount of captured gas on a lower end cryopanel of the upper structure.

Abstract: An exposure apparatus of the present invention includes a vacuum container accommodating a structure, a vacuum pump configured to increase the degree of vacuum achieved inside the vacuum container, a radiation unit configured to perform a heat exchange through radiation for the structure, a temperature detecting unit configured to detect the temperature of the structure, and a control unit configured to control the radiation unit based on the detected temperature, wherein the radiation unit is arranged at a position determined so that the radiation unit does not interfere with a heat exchange achieved through radiation between the vacuum pump and the structure.

Abstract: A cryopump includes: a cryopump housing arranged to define an inner space of the cryopump from an outer environment; an exhaust duct arranged to connect with the cryopump housing so as to exhaust fluid from the inner space of the cryopump to the outer environment; and a filter structure. The filter structure includes: a filter arranged to remove a foreign body from fluid exhausted through the exhaust duct; and a filter mounting member arranged to mount the filter to the exhaust duct, wherein at least a part of a bypass flow passage that diverts fluid from the filter is formed in the filter mounting member.

Abstract: Ice condensed in a portion in a case in which a cryogenic refrigerator is installed, which is cooled by the cryogenic refrigerator, is melted by increasing a temperature of the ice to a melting point of the ice or higher. Then, while the temperature of the melted ice and a pressure thereof are kept to be equal to or higher than a freezing point of water, the pressure is reduced by rough evacuation so as to vaporize water. At a time at which the water is discharged, the pressure is further reduced so as to discharge water vapor. In this manner, regeneration of water is performed in accordance with a state of the water (i.e., a solid state, a liquid state, and a gas state), thereby shortening a regeneration time.

Abstract: A cold trap is provided with a cold panel provided in a pumping path such that the panel is exposed, a refrigerator thermally coupled to the cold panel and operative to cool the cold panel; and a controller configured, in a regeneration process for evaporating a gas frozen on the surface of the cold panel and discharging the gas outside using the vacuum pump, to control the refrigerator so as to raise the temperature of the cold panel to a temperature exceeding a non-liquefaction temperature range and to adjust a pressure in the pumping path at the temperature so that the gas frozen on the surface of the cold panel is evaporated without being melted, the non-liquefaction temperature range being a range in which it is guaranteed that a gas frozen on the surface of the cold trap is evaporated without being melted.

Abstract: An apparatus and method are provided for pumping a cryogenic fluid from a storage vessel. The cryogenic fluid is pumped from the storage vessel to a heat exchanger and then to a delivery conduit. A pressure sensor measures fluid pressure in the delivery conduit. An electronic controller is programmed to monitor a signal from the pressure sensor, process the signal to determine from the measured process fluid pressure when cryogenic pump performance is degraded, and to send a signal to an operator of the apparatus indicating when the electronic controller determines that cryogenic pump performance has degraded below a predetermined threshold volumetric efficiency.

Abstract: A cryopump pumps gas from a vacuum chamber in a vacuum apparatus performing vacuum processing. The cryopump comprises: a refrigerator; a cryopanel cooled by the refrigerator; and a controller configured to control an operating cycle of the refrigerator such that the cryopanel is controlled so as to have a target temperature. When an operating cycle of the refrigerator has reached a first determination reference, the controller monitors the operating cycle for a first determination period of time, and when the operating cycle has reached a second determination reference, which corresponds to a higher load than the first determination reference, the controller monitors a temperature of the cryopanel for a second determination period of time, which is shorter the first determination period of time.

Abstract: A pump for supplying a cryogenic liquid coolant in accordance with the present invention includes: a housing having an inlet port for introducing a cryogenic liquid coolant, an outlet port for discharging the cryogenic liquid coolant introduced through the inlet port, and a chamber for connecting the inlet port and the outlet port; an impeller rotatably retained in the housing for introducing the cryogenic liquid coolant through the inlet port and discharging the same through the outlet port; and a vapor exhausting part provided in the housing for exhausting vapor generated from the cryogenic liquid coolant.

Abstract: The cryogenic fluid generator includes at least one pump assembly having an actuator mounted to a container assembly. A pump assembly housing includes a longitudinal positioning opening and a pressurization cavity at a distal end terminating with a pump assembly outlet. An internal check valve assembly includes a shaft positioned within an opening of the pump assembly housing that extends into the pressurization cavity. The shaft is attached to the actuator and includes a longitudinal guidance slot; a fluid passageway; and, an internal sealing surface. A positioning bar assembly is positioned within the guidance slot. A connecting rod is securely connected at a first end to the positioning bar assembly, the connecting rod being positioned within the fluid passageway and terminating with a flow inhibiting element. A seal is positioned between the pump assembly housing and the check valve to provide a closure for the pressurization cavity.

Abstract: A cryopump includes a radiation shield provided with a main inlet at one end thereof and a sub-inlet in a side thereof; and a cryopanel assembly cooled to a temperature lower than that of the radiation shield. The cryopanel assembly includes an upper structure having at least one cryopanel and a lower structure having at least one cryopanel. The upper and lower structures are arranged inside the radiation shield along a direction away from the main inlet. A frost accommodating space connected to the sub-inlet may be arranged between the upper and lower structures such that an amount of captured gas on an upper end cryopanel of the lower structure is greater than an amount of captured gas on a lower end cryopanel of the upper structure.

Abstract: A method and apparatus for compressing a natural gas stream is disclosed. The natural gas stream to be compressed is liquefied and then compressed by means of at least one cryogenic pump. Liquefaction of the natural gas stream to be compressed preferably takes place using the energy from a low-temperature process, specifically in the exchange of heat countercurrent to at least one medium to be heated, preferably countercurrent to a cryogenic medium.

Abstract: A cryopump includes: a cryopump chamber having an inlet port through which a gas to be pumped is introduced; a refrigerator provided with a second cooling stage provided in the cryopump chamber; an intermediate member thermally coupled to the second cooling stage; and a cryopanel having a connecting part connected to the intermediate member at a position farther from the inlet port in the direction in which the gas is introduced than the second cooling stage, and extending from the connecting part toward the inlet port. For example, a cryopump having a suspended panel structure is provided.

Abstract: A cryopump regeneration method includes a temperature raising step of raising the temperature of a cryopanel so as to vaporize gas molecules condensed on the exhaust surface of the cryopanel, an evacuation step of evacuating a pump vessel, a determination step of determining whether the internal pressure of the pump vessel has reached a set pressure higher than the water vapor pressure at 0° C., a pressure rise test step of stopping the evacuation and performing a pressure rise test, and an observation step of observing residual water based on the internal pressure of the pump vessel.

Abstract: A cryopump apparatus includes a sensor which detects at least one of the temperature and pressure in a cryopump, a controller which detects a change in at least one of the temperature and pressure in the cryopump on the basis of the detection result obtained by the sensor, thereby determining the connection state between the controller and the cryopump, and a display device which displays an abnormal point for the cryopump estimated from the determination result obtained by the controller.

Abstract: A vacuum system comprises, as an integral assembly, a vacuum pump with drive motor, a purge valve, a roughing valve and an electronic control module. A cryogenic vacuum pump and a turbomolecular vacuum pump are disclosed. The control module has a programmed processor for controlling the motor and valves and is user programmable for establishing specific control sequences. The integral electronic control module is removable from the assembly and is connected to the other devices through a common connector assembly. In the turbomolecular pump system proper introduction of a purge gas through the purge valve is detected by detecting the current load on the pump drive or by detecting foreline pressure. To test the purge gas status, the purge valve may be closed and then opened as drive current or pressure is monitored. After power failure, the controller will continue normal drive of the turbomolecular pump so long as the speed of the pump has remained above a threshold value.

Abstract: A pumping/compressing apparatus for use in a fluid handling system transferring a fluid from one location, e.g., a tank, to another location or to an end use is provided. The apparatus basically includes a motor and a multistage, e.g., two stage, device including at least one reciprocating piston, an inlet stage chamber, an outlet stage chamber, an inlet, and an outlet. The piston is arranged to be reciprocated at multiple, e.g., respective first and second, speeds. The second speed is higher than the first speed, whereupon when the piston is reciprocated at the first speed the device effectively pumps liquid or mostly liquid to the outlet. When the piston is reciprocated at the second speed the device effectively compresses gas or mostly gas fluid and provides it to the outlet. A blowby port may be provided to provide blowby fluid back to the tank or the device.

Abstract: The apparatus comprises a double walled vacuum insulated vessel defining a cryogen space for holding a cryogenic fluid, a pump assembly comprising a pump with a suction inlet disposed within the cryogen space, and at least one elongated member extending from the pump to a drive unit disposed outside the cryogen space. The elongated member comprises an elongated non-metallic section that has a thermal conductivity that is less than that of a structurally equivalent elongated stainless steel member of the same length. In preferred embodiments, the elongated member can be one or both of a drive shaft or a rigid structural member for supporting the pump and holding it in a fixed relationship to the drive unit. The method employs the apparatus to increase hold times for holding cryogenic fluids by reducing heat leak into the cryogen space.

Abstract: A method of generating a high-level vacuum comprises evacuating a chamber having a substantially-pure gas therein to a medium-level vacuum, and freezing the residual gas to generate the high-level vacuum within the chamber. Impurities, such as atmospheric air, may be purged from the chamber by evacuating the chamber to a medium level vacuum (e.g., around 10?2 Torr) and subsequently filling the chamber with the gas. This purging process may be repeated multiple times to decrease the level of impurities in the gas filling the chamber. The substantially-pure gas may have an impurity-level of less than approximately 100 PPM and may comprise carbon-dioxide, although the scope of the invention is not limited in this respect. The medium level vacuum may range between approximately 1×10?2 Torr and 5×10?2 Torr allowing the use of a roughing pump, and the high-level vacuum may range between approximately 1×10?5 and 1×10?8 Torr.

Abstract: A double-acting, reciprocating piston, high discharge pressure, cryogenic fluid pump having a unique blow-by venting system. In two different embodiments, a double-acting piston has two pair of piston heads and two sets of seals. In a first embodiment, a blow-by vent system is provided by a passageway that communicate with the cylinder between the pair of piston heads and vents the vapor or fluids axially through the piston rod. A second embodiment has the two piston heads separated on the piston rod a distance equal approximately to the stroke of the piston. This provides an annulus around the piston rod forming a manifold in communication with passageways through the pump cylinder wall to vent blow-by vapors or fluids. In both cases, blow-by vapors or fluids that leak or creep past the piston heads are vented to the liquid being pumped inside an insulating enclosure surrounding the pumps.