Abstract: An improved cryopumping apparatus which comprises a cryopumping space which may be alternately opened and closed from the surrounding area by moveable panels, trubular cryopanels within said cryopumping space through which a coolant such as liquid helium may be passed, and an apparatus for spraying liquid argon onto said cylindrical cryopanels in order to enhance the cryogenic entrapment of such low-z ions, atoms, and molecules as hydrogen and helium.

Abstract: In a cryopump, condensation of gases such as argon, oxygen and nitrogen on surfaces other than the second stage array 38, 40 is avoided to prevent cross over hang up and pressure instability. To prevent condensation of argon, oxygen and nitrogen on the frontal cryopumping array 46, that array is held to a temperature of at least 50.degree. K. A heat load to the first stage increases as the temperature of the first stage drops. That heat load is provided by a high emissivity radiation shield 44 or by a thermal switch 56, 58. Condensation of argon and other gases on the second stage refrigerator cylinder 32 is avoided by a close fitting sleeve 52 positioned over the refrigerator cylinder 32 in thermal contact with the second stage heat sink 30 but out of thermal contact with the cylinder 32.

Abstract: This invention relates to a method for the cryopreparation of biological tissue samples for ultrastructural analysis. The process comprises vitrifying a biological tissue sample under severely rapid conditions and then depressurized. The depressurized, vitrified tissue sample is brought to equilibrium at a temperature of less than -140.degree. C. The tissue sample is then dehydrated while maintained in a state of thermal equilibrium. After reaching equilibrium the tissue sample is infiltrated with a degassed resin and followed by a polymerization of the resin to form an embedded tissue sample. This invention additionally relates to a sample holder apparatus which has unique use characteristics in the process of this invention.

Abstract: In a vacuum generating system having a liquid ring vacuum pump preceded in a gas flow path by a precompressor and followed by a liquid separator, the precompressor is driven by steam produced in a heat exchanger in contact with the working fluid of the vacuum pump. The working fluid is kept at a temperature exceeding the boiling point of water.

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 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: There is provided a method and apparatus for cooling elongate product, such as wire. A housing is provided to define a chamber with an inlet for the product and an outlet for the product, both the inlet and outlet being larger in area than the product. Within the chamber liquid is sprayed against the product to cool it, and suction is utilized to withdraw air and liquid from the chamber at a rate which results in an air-wiping effect on the product by the air entering the chamber through the inlet and outlet.

Abstract: A process for the freezing of organic tissue is disclosed, in which the atmospheric pressure in contact with the tissue is gradually lowered before or during the freezing process. The decompression is done at a rate and to a degree whereby a substantial portion of the gaseous matter dissolved in the cellular fluid is released to the atmosphere, without substantial vaporization of the fluid itself. The release of the dissolved gases permits freezing of the tissue without damage to the cellular structure, and thus permits a full return to the original appearance and consistency upon thawing.

Abstract: Process and apparatus for recovery of vapor which is contained with air in a space above a volatile liquid which is stored in a container, especially a petroleum distillate or other costly liquid. The process employs the pressure build up due to thermal effects on the space above the volatile liquid to drive the vapor through a heat exchanging region at which a venturi evaporative cooling unit is used to extract heat from the vapor and partially condense the vapor without significant compression. A part of the condensed vapor is recycled to the heat exchanging region and introduced as a spray for a condensation "seeding" effect. The vapor is further cooled after cooling by the venturi evaporative cooling unit in a second and even a third cooling stage; these stages can include use of a conventional refrigeration unit to chill a heat exchanger and an ultra low temperature can be achieved by expanding liquified gas such as nitrogen in an insulated cyclone to achieve high percentage recovery of the vapor.

Abstract: An air cooling and water condensate removal panel has at least two interconnected capillary systems close to a plate having cooling means for removing heat from the plate. The first capillary system exists in a porous, thin outer layer having a very fine capillary structure which presents a cool, wettable surface upon which moisture in the air condenses. The outer layer is maintained cool by the cold plate. The condensate water soaks through the thin porous outer layer and is drawn into the interconnected second capillary system. The second capillary system is substantially coarser than the first system to cause the water to be drawn away more rapidly than the condensate can form upon the outer surface. The water in the coarser capillary system is drawn into a discharge pipe, preferably by employing a pump to maintain a mild vacuum in the pipe.

Abstract: The invention relates to a method for treating moist pulverulent material and is particularly useful for removing the moisture from such material. In one aspect of the invention, the material is hot foundry sand, where the sand is first moistened by the addition of water and then the moist sand is treated in a vibrating container under vacuum.

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: A method of cooling a block of porous material comprising inserting said block into a chamber, subjecting the chamber to air pressure less than that of the ambient air and inserting means into the said block to induce a flow of cooling air through the interior of the block to the said chamber, whereby the lower pressure in the chamber causes the cooling air to flow inwardly through the means inserted in the block for cooling the block.

Abstract: In a water chilling plant and method, normally with two or more stages of vacuum chilling, the vapor from the chilling stage or stages is presented to an air cooled heat exchanger for condensation in two different flow streams at different stages of compression, so that the cooler air nearer the air inlet works on vapor at a lower stage of compression.

Abstract: A method of cooling a moisture-containing foodstuff article is described, which involves placing the article in a chamber and evacuating the chamber to reduce the pressure in the chamber, whereby moisture evaporates from the article and the latent heat of the moisture is extracted from the article. In order to prevent damage to the article by a too-rapid evaporation, the evacuation is controlled in response to dimensional change (typically the height) of the article.The invention also includes a method of controlling the evacuation of the chamber by progressively opening a valve in the pumping system to reduce the impedance (and hence increase the pumping rate) of the pumping system. This progressive opening of the valve is however, subject to an over-riding control which may arrest the opening action or initiate closing of the valve in response to a detected dimensional change of the article.

Abstract: A multiple stage cryogenic vacuum pump is disclosed for transferring matter or species between a gas and a vacuum chamber. The vacuum chamber has an orifice through which the matter or species moves and through which some of the gas leaks into the chamber. The chamber also has an interior surface which is spaced from the path of movement of the matter or species and encircles such path, and an internal divider extending to a position adjacent the interior surface and dividing the chamber into a first region adjacent the orifice and a second region downstream from the first region, with the interior surface extending in both regions. The surface is cooled by a single refrigerating device to below the condensation temperature of the gas, to produce a pressure below atmospheric in the first region and a lower pressure in the second region. The divider contains an aperture through which the matter or species travels and may itself be cooled to precool gas contacting it.

Abstract: The temperature of bakery products is reduced immediately after the discharge thereof from the oven, by means of vacuum, by first subjecting the bakery products to a substantially linear pressure reduction as a function of time at a rate of not more than 60 mm Hg per second through at least half of the total pressure drop to be achieved. The pressure reduction rate is then allowed to increase substantially for a terminating vacuum treatment. At least one vacuum chamber is provided and is adapted to be connected to a source of vacuum through a vacuum conduit and a valve, and has a closeable opening for bringing bakery products into and out of the chamber. In the vacuum conduit, in parallel to a servo-valve serving to apply a full vacuum effect from the source of vacuum during the remaining portion of the total pressure drop, there is inserted a by-pass conduit having a permanently open cross-section which can be adjusted to provide the substantially linear pressure reduction.

Abstract: Atomic hydrogen, for use as a fuel or as an explosive, is stored in the presence of a strong magnetic field in exfoliated layered compounds such as molybdenum disulfide or an elemental layer material such as graphite. The compound is maintained at liquid helium temperatures and the atomic hydrogen is collected on the surfaces of the layered compound which are exposed during delamination (exfoliation). The strong magnetic field and the low temperature combine to prevent the atoms of hydrogen from recombining to form molecules.

Abstract: An evaporative refrigerator or cooler comprising a bundle of spaced, porous walled tubes closed at one of their ends and vented to a vacuum at the other end is disclosed. The tube bundle is surrounded by a water jacket having a hot water inlet distribution manifold and a cooled water outlet through a plenum chamber. In operation, hot water is pumped into the jacket to circulate around the tubes, and when this water meets the vacuum existing inside the tubes, it evaporates thereby cooling the water in the jacket. If cooling proceeds to the point where water penetrating or surrounding all or part of the tubes freezes, operation continues with local sublimation of the ice on the tubes while the circulating water attempts to melt the ice. Under some conditions, both sublimation and evaporation may take place simultaneously in different regions of the device.