Abstract: The inner cryopanel of a cryopump includes a substrate having a plurality of holes such that the open areas represent 30% to 70% of the surface area of the substrate. A layer of cryosorbing material is secured to one surface of the substrate. An imperforate panel is juxtaposed to said one surface of said substrate.

Abstract: A cryosorption pump comprises a pump housing; a supply conduit merging into the pump housing for introducing sorption material thereinto; an outlet conduit opening into the pump housing at a location below and spaced from the supply conduit; a plurality of heat conducting wall surfaces disposed in the pump housing; a refrigerator operatively connected to the wall surfaces for cooling them to a cryogenic temperature to which the sorption material situated between the wall surfaces is exposed; a regenerator connected to the outlet and supply conduits for regenerating sorbent-laden sorption material received from the pump housing by means of the outlet conduit and for admitting sorbent-free sorption material into the supply conduit; a first conveyor arranged in the outlet conduit for advancing sorbent-laden sorption material from the pump housing into the regenerator; and a second conveyor arranged in the supply conduit for advancing sorbent-free sorption material from the regenerator into the pump housing.

Abstract: For a given temperature differential between a refrigerated heat sink (28) and frontal cryopanel array (46), the mass of the entire cryopump array is minimized by providing thermal struts (54) between the heat sink and the frontal array. The thermal struts extend through, but are isolated from, the primary pumping surface to minimize their lengths. The struts support the frontal array independent of the side radiation shield to facilitate fabrication. To further reduce the temperature differential to the frontal array, heat pipes may be provided. Parallel heat pipes or solid thermal struts may provide the thermal path during cooldown of the system. By reducing the temperature differential between the frontal cryopanel array (46) and refrigerated heat sink (28) through the use of solid thermal struts or heat pipes the load carrying capability of a cryopump can be improved.

Abstract: A cryopump 20 for differentially pumping water vapor and inert gases from a work space comprising a two stage refrigerator 45 in which a radiation shield 32 substantially encloses a second stage cryopanel 40. The radiation shield 32 incorporates a baffle plate 34 which condenses higher condensing temperature gases and restricts passage of low condensing temperature gases through orifices 36 to the second stage cryopanel 40. Backside pumping ports 38 provide a flow path to the second stage refrigerator for residual gases within the cryopump 20. This creates a high vacuum within the cryopump and allows it to operate at maximum efficiency.

Abstract: A pump for compressing a low temperature high density liquid gas, e.g. liquid helium, wherein the piston is driven by a motor through a four bar linkage which converts rotary motion to reciprocating motion. The pump also includes an improved piston ring assembly, piston venting apparatus and a cushioned discharge valve. A two-stage pump in combination with support equipment provides an improved pumping cycle wherein low temperature density liquid or gas e.g. liquid helium can be withdrawn from a storage reservoir, vaporized and compressed into cylinders.

Abstract: A cryopump installation in which a novel cryopump 20 maintains a work chamber 12 at continuous high vacuum while periodically evacuating a load lock 14 in order to allow transfer of material from the load lock 14 to the work chamber 12 without disruption of the work chamber environment. The cryopump has pumping ports 46 positioned on the radiation shield 50 in order to pump plenum 72 to a high vacuum. Load lock gases enter the cryopump through port 46 and are condensed and adsorbed by the radiation shield 50 and second stage cryopanel 54.

Abstract: The invention discloses a cryopump comprising a primary cryopanel 67 associated with a low temperature heat sink 60 having means for adsorbing a first low boiling point gas and a secondary cryopanel 80 associated with heat sink 60 and a higher temperature heat sink 48 having means for condensing a higher boiling point gas. There are means 90 for selectively conducting heat to the primary cryopanel to raise the temperature of the cryopanel above that which is necessary to cause said first gas to become desorbed from said cryopanel while having minimal effect on the capacity of the higher temperature heat sink.

Abstract: A pump for cryogenic liquids is provided with an enclosing vessel of the construction of a Dewar flask. A submerged multistage rotary pump is suspended from the mouth of the flask by means of a system providing thermal insulation opposing the flow of heat down the neck of the flask. The drive motor is coupled to the drive shaft of the immersion pump through a magnet coupling of which the elements are separated by a pressure seal. The latter and the extensive thermal insulation make the pump suitable for pumping liquid air or liquid nitrogen in a pressurized closed circuit and the presence of a supply of the cryogenic liquid around the pump itself makes it possible to start the pump at once after a quiescent period. A level-control sonde operates to assure that the presence of the necessary minimum of liquid in the vessel.

Abstract: A cold surface for cryogenic pumps in the form of a (filled/through-streamed) double wall which is acted upon by a liquid refrigeration medium, as well as to a process for the production of such a cold surface. The double wall is formed by a series of thin-walled narrow tubes which are interconnected with each other, to which there are presently attached thin axially parallel, good heat conductive metal lamellas, wherein the tube diameter, tube spacing and wall thickness, as well as the lamella thickness, with consideration being given to a minimization of the total mass of the surface, are so correlated and dimensioned with respect to each other that the temperature differences within the lamellas of the surface which is acted upon with liquid refrigeration medium at a maximum occuring heat loading will remain below 0.1.degree. K.

Abstract: The piston compressor has a cylindrical block with at least one cylinder lining in which a piston moves without making contact. A collecting chamber for leakage gases which escape along the piston is provided at an end of the cylinder liner remote from the compression chamber. The cylinder liner is double walled to form a chamber through which forced coolant can be passed. In addition, an annular space is provided between the cylinder liner and the cylinder block to prevent leaking gas from passing into the cooling water contained in the cylinder block or cylinder liner.Forced cooling results in a good direct cooling of the cylinder liner.

Abstract: A piston pump having an intake valve whose valve member is approached by the pump piston. The piston magnetically attracts the valve member during the intake stroke to overcome the force of the spring biasing the valve member into its closed position.

Abstract: A cold surface, (e.g. for use in a so-called cryopump, i.e. a cryogenic vacuum vapor pump), is formed by a reservoir for liquid hydrogen surrounded by a double-wall vessel over an intervening evacuated insulating space. The lowest points of the compartment formed between the walls of the double-wall vessel and the interior of the liquid helium reservoir are connected by a conduit provided with a valve.

Abstract: For a given temperature differential between a refrigerated heat sink and frontal cryopanel array, the mass of the entire cryopump array is minimized by providing thermal struts between the heat sink and the frontal array. The thermal struts extend through, but are isolated from, the primary pumping surface to minimize their lengths. The struts support the frontal array independent of the side radiation shield to facilitate fabrication. To further reduce the temperature differential to the frontal array, heat pipes may be provided. By reducing the temperature differential between the frontal cryopanel array and refrigerated heat sink through the use of solid thermal struts or heat pipes the load carrying capability of a cryopump can be improved. Heat pipes may also serve as a thermal switch between a heat sink and a cryopanel.

Abstract: A cold trap for use in a high vacuum system to analyze the vapor component or components of the gases in, or introduced into, the vacuum system, including the assessment of the partial pressure of any specific component which may be present in the said gases, comprising a chamber closed at its upper end by a thin metallic diaphragm dished inwardly to receive a liquid coolant such as liquid nitrogen, an outlet to interconnect the chamber with a high vacuum system, and means to introduce successive doses of liquid coolant into the diaphragm. This construction allows the trap to be rapidly cycled. It is shown to be advantageous for the radius of curvature of the lowest part of the diaphragm to be such that the area of the diaphragm which remains at the temperature of the coolant until all the coolant has evaporated is larger than the effective area of the outlet.

Abstract: Cryopump apparatus for evacuating very large chambers to ultra high vacuums includes cryogenic panels alternating with radiation shields having a unique Z-configuration which optically blind the panels. The panels and shields are supported by and housed within structure having specific components slidable along one another to thereby permit necessary movement of the components when the apparatus is subjected to cool-down or warm-up. The apparatus is characterized by very high pumping speeds and is capable of cryopumping from both sides thereof.

Abstract: Two stage cryogenic pump having axially spaced baffle members for shielding the second stage from external thermal radiation while permitting substantially unimpeded gas flow from the inlet opening to the second stage.

Abstract: An improved cryopump has cryopanels with pressed zeolite plates mounted thereon. The plates are maintained in intimate but unbonded contact with the panels by use of spring-type mechanisms. Older style panels have clay-bonded zeolite casts attached to their surfaces. The new configuration allows relative expansion and contraction between the zeolite plates and the panels, thereby improving durability of the zeolite. The resilient attachments assure that intimate contact and consequent good cooling of the zeolite adsorptive surface will be maintained during operation of the pump. The zeolite panels are desirably less than about 8 mm thick and are made by isostatic compaction of powders having pore sizes in the range of 2-25.times.10.sup.-10 m.

Abstract: A cryogenic apparatus comprises refrigeration means utilizing a two-stage expansion of compressed helium gas that circulates in a closed loop, whereby a first pumping stage can be maintained at a temperature in the range from 50.degree. K. to 80.degree. K. and a second pumping stage can be maintained at a colder temperature in the range from 10.degree. K. to 20.degree. K. The first pumping stage comprises an array of louvers of chevron configuration. These louvers enclose the second pumping stage, and serve as baffles to shield the pumping surfaces of the second stage from thermal radiation that would reduce the usable refrigeration capacity of the second stage for removing gases from a chamber to be evacuated. The chevroned baffles also protect a cryosorbent coating on the interior surfaces of the second stage from becoming iced or plugged by gas species that cryocondense at the higher temperature of the first stage.

Abstract: Two-stage cryogenic pumping apparatus having individual plate members with cryosorbent coatings secured by removable fasteners to permit easy assembly and replacement of the plate members. The plate members are spaced apart to provide relatively unrestricted access to the cryosorbent material for the gases to be adsorbed thereon.

Abstract: A cryopump consisting of cryopanels attached to an elongated source of refrigeration in which heat is transferred from cryopumping surfaces to various stages of refrigeration by conduction including a chevron baffle or louver mounted parallel to the long axis of the refrigerator source and directly to the warmest stage of refrigeration.

Abstract: Cryopump apparatus includes means for supplying cryogenic fluid, means for supplying higher temperature refrigerant fluid, a panel having heat exchange surfaces on respective opposite sides thereof, with a conduit conducting cryogenic fluid therethrough, and a zigzag passageway formed by opposite sides of two radiation shields in spaced relationship with each other having the panel therebetween. The radiation shields are spaced from the panel, optically enclosing the panel therewithin. Corresponding edges of adjacent shields define open bottom channel-configured passageways for flow of gas therethrough to respective heat exchange surfaces of a panel interjacent the shields. The shields include conduits for flow of refrigerant fluid therethrough. Heat insulative positioning spacer means contact two adjacent panels and a shield therebetween, maintaining the panels and shield in spaced relationship.

Abstract: A cryopump device comprising a refrigerator section which has at least two expansion chamber cooling elements disposed in a space to be evacuated, a shielding wall disposed in the space encircling both expansion chamber cooling elements and formed by a thermally conductive material, the shielding wall being in heat transfer contact with one of the expansion chamber cooling elements, a condensation panel disposed inside the shielding wall and being in heat transfer contact with the other of the expansion chamber cooling elements, the shielding wall having an opening proximate the condensation panel so that the space is cooled by the other expansion chamber cooling element through the condensation panel.

Abstract: The invention relates to a cryogenic pump for liquid gases which comprises, within a housing, a cylinder connected to the supply of liquified gas through a non return valve and to an overflow duct. A movable piston is displaceble within this cylinder defining a suction chamber and an evacuation chamber and this piston carries a skirt cooperating with a piston rigidly fixed to the frame defining together a compression chamber. This compression chamber is connected through a non return valve to the high pressure output of the pump and to the suction chamber by means of at least one passage provided with a non return valve.

Abstract: A cryopump having a cryopanel adapted for being cooled by a first refrigerant and shielded from radiation incident thereon by shields adapted for being cooled with a second refrigerant is disclosed. The cryopanel and the radiation shield are fabricated with a first material having high thermal conductivity, such as aluminum, while means for distributing refrigerant from refrigerant dewars to the cryopanel and shields are made of a second material, such as stainless steel. The stainless steel and aluminum sections are connected by an aluminum-steel transition connector adapted for providing vacuum tight connections at cryogenic temperatures. Both the cryopanel and chevrons comprising the shields are fabricated and extruded aluminum with coolant passages formed therein. Thermal distortions during operation are compensated by the use of stainless steel bellows within refrigerant distribution lines.

Abstract: This invention relates to cryopumps, and consists in the incorporation of walls for trapping by condensation exemplified by outer faces of partitions, and walls for trapping by adsorption, exemplified by inner faces of these partitions. These walls define a confined area in the closed position, in which the adsorbent is isolated from condensable gases. Once these gases have been condensed on the said outer faces, the partitions are opened to place the adsorbent layers in communication with the remainder of the pumping enclosure.The invention is applicable to the production of high and uncontaminated vacua (in particular for the production of thin films).

Abstract: Conventional installations for pumping of liquid LNG (liquefied natural gas) from a sealed tank of a marine vessel to a shore installation commonly include a pump immersed in the liquid, a riser pipe from the pump to a level above the liquid, a stop valve on the riser pipe outside the tank, and a connection to the header leading to the shore installation. With the stop valve closed, operation of the pump can cause slamming of the liquid, accelerating up the riser pipe, against the stop valve, to the extent that the valve or piping may be damaged or destroyed. The invention provides a method of operation, and apparatus to permit it to be carried out, whereby a pocket of non-liquefiable gas is formed in the riser pipe above the liquid level so that, upon operation of the pump with the stop valve closed, although LNG vapor in the riser pipe may become compressed to liquid, the pocket of gas remains to act as a compressible buffer between the rising liquid and the stop valve.

Abstract: A liquid cryogen pump in which liquid is maintained on both sides of the pump piston during operation. In the preferred embodiment, vapor, when present in the pump chamber, is passed from in front to behind the piston by providing a predetermined clearance between the piston and the cylinder in which it is reciprocated. The clearance is preferably large enough to pass enough liquid cryogen to maintain the desired head of liquid behind the piston. In the embodiment set forth, the pump is arranged so that it can be immersed in the liquid cryogen to be pumped with its pumping chamber and valves at or close to the bottom of the liquid cryogen supply. Heat transfer between the warm, upper end of the pump and its cold end is effectively restricted, and, preferably, the warm end is connected to the cold end of the pump by thin-walled tubular members formed of low thermal conductive materials to minimize heat transfer by conduction.

Abstract: A mixed phase pump for rapidly rotating cryogenic machinery is disclosed, preferably for installation to a superconducting generator rotor. The superconducting generator rotor includes an inner and outer rotor structure joined in a thermally insulated configuration not unlike that of a Dewar flask. The inner rotor contains a support cylinder for a refrigerant, typically helium, which when refrigerated to 3.5.degree. Kelvin at one half a standard atmosphere under the normal rapid rotation of the axially aligned support cylinder, classifies itself into a two-phase liquid gas system. The phases include an outer cylindrical helium pool and an axially inward gaseous core separated by a cylindrical gas-liquid interface. During normal operation of the rapidly revolving rotor, a pump removes the gas for recooling to a liquid state by receiving the gas in the vicinity of the axis of the rotor at an inlet.

Abstract: The invention provides a high vacuum pump system of high pumping speed in which the surfaces that are to be cooled are coated with adsorbents in such a manner that it is possible to bale out and activate the coatings at temperatures between 250.degree. and 400.degree. C and then to use them for the maintenance or repeated generation of high vacua containing no hydrocarbons down to pressures as low as about 10.sup.-8 torrs.

Abstract: The invention relates to a regeneration-type cryopump which has an annular reservoir for liquid nitrogen situated above an annular reservoir for liquid helium and incorporates, sliding in the central opening in the said reservoir, a valve member which is mounted on a rod. When the valve member is in one position, the cryopump is in normal operation, whereas when the valve member is in another position and rests against a seating, regeneration may take place.Such a pump may be used for generating very high vacua.

Abstract: A method of controlling the capacity of a gas blower for pumping gas at a given discharge pressure involving cooling the gas at the suction side of the blower. The method is especially useful for controlling the pressure in a liquefied gas storage tank so as to maintain it substantially constant. The boil-off gas in the tank is exhausted by a gas blower and liquefied gas is injected into the boil-off gas exhausted from the tank at a point on the suction side of the blower for cooling the boil-off gas exhausted from the tank prior to its being pumped by the blower. The amount of liquefied gas injected into the boil-off gas is proportional to the pressure of the boil-off gas in the storage tank.

Abstract: A double acting piston pump for cryogenic mediums is disclosed. The pump includes a vertically positioned cylinder having a base portion and a cover portion, and inlet valves are disposed in the cover portion and the base portion for admitting the cryogenic medium into the cylinder and for providing a pressure component of approximately zero against the direction of flow of the cryogenic medium. Outlet valves are disposed in the cover portion and the base portion for discharging the cryogenic medium from the cylinder. A piston is slideably mounted in the cylinder and a drive rod connected to the piston extends through either the cover portion or the base portion of the cylinder. A drive arrangement engages the drive rod for actuating the piston. A housing is also provided which has a portion defining the cylinder. The drive rod and the drive arrangement are mounted in the remaining portion of the housing, whereby the housing is common to the piston, the drive rod and the drive arrangement.

Abstract: Motor driven inducer equipped centrifugal pumps have the inducer and centrifugal pump impellers mounted on a motor shaft on opposite ends of the motor so that the inducer will not create prerotation in the impeller entrance permitting both the inducer and the impeller to operate independently and produce a head which is the sum of the two individual heads produced by the inducer and the impeller. The heretofore required relationship between the inducer outer diameter and the impeller inner diameter is eliminated and inducer sizes may be varied for best efficiency. Pumpage is vented to the motor through a hollow motor shaft to cool the motor and lubricate the bearings. Multi-staging of the pump is simplified with standard parts being stacked to produce the desired number of stages and, in the multi-stage embodiment, the second stage impeller is subjected to an upward thrust by the pumpage from the first stage to balance inducer thrust loads on the bearings with opposite impeller thrust loads.

Abstract: A suction of fluid control valve for a submerged type pump for storage containers containing cryogenic fluids. The valve is normally open and includes a fluid control valve member having ports for communicating with the liquid stored in the storage container. A gas source is provided for producing relative movement between the valve members for sealing off the fluid ports and exposing the ports to thereby control the flow of the stored liquid into the pump housing.

Abstract: a system and method are provided for transferring a liquid cryogen from a supply tank to a receiver tank by pressurizing the supply tank with cold vapor from the receiver tank. This method minimizes heat added to the transferred liquid and minimizes the temperature of the vapor returned to the supply tank, making it particularly useful for optimizing the transfer of liquid cryogens such as helium, hydrogen, nitrogen and oxygen which vaporize well below ambient temperatures. A cold vapor pump is provided which is insulated from ambient temperatures for pumping the cryogen vapor from the receiver tank to the supply tank with a minimum of heat input.

Abstract: Cryopump apparatus includes means for supplying cryogenic fluid, means for supplying higher temperature refrigerant fluid, a panel having heat exchange surfaces on respective opposite sides thereof, with a conduit conducting cryogenic fluid therethrough, and a zigzag passageway formed by opposite sides of two radiation shields in spaced relationship with each other having the panel therebetween. The radiation shields are spaced from the panel, optically enclosing the panel therewithin. Corresponding edges of adjacent shields define open bottom channel-configured passageways for flow of gas therethrough to respective heat exchange surfaces of a panel interjacent the shields. The shields include conduits for flow of refrigerant fluid therethrough. Heat insulative positioning spacer means contact two adjacent panels and a shield therebetween, maintaining the panels and shield in spaced relationship.