Abstract: Liquid carbon dioxide substantially free of particles is prepared by evaporating liquid carbon dioxide, passing the resulting gaseous carbon dioxide through a suitable filter to remove particles therefrom and cooling the particle-free gas to reliquefy it.

Abstract: The present invention discloses a heat tube device through which a working fluid can be circulated to transfer heat to air in a conventional air conditioning system. The heat tube device is disposable about a conventional cooling coil of the air conditioning system and includes a plurality of substantially U-shaped tubes connected to a support structure. The support structure includes members for allowing the heat tube device to be readily positioned about the cooling coil. An actuatable adjustment device is connected to the U-shaped tubes for allowing, upon actuation thereof, for the heat tubes to be simultaneously rotated relative to the cooling coil for allowing the heat transfer from the heat tube device to air in the air conditioning system to be selectively varied.

Abstract: The present invention relates to an isothermal container with isothermal walls comprising a thermally conducting reservoir (10) for refrigerant product disposed in the upper part of the container; a baffle (3) of thermally insulating material, of a size slightly less than the internal section of the container and having about its periphery an annular space (8) suitable for the free passage of the gas is disposed horizontally below the reservoir (10), at a distance sufficient to delimit in the upper part of the container a region (6) suitable for natural convective heat exchange; the reservoir (10) and the baffle (3) comprising securement and support means (4, 12, 13, 14) in the container (1), characterized in that it computes at least one food compartment (c) disposed in the container, below the plate forming a baffle, of a size substantially less than the internal volume of the container, a space remaining free about the compartment (c) in the container.

Abstract: An improved refrigeration system is provided for use in a rail car or the like to refrigerate perishable items such as produce. The refrigeration system includes a plurality of modular ceiling panels mounted near the roof of a rail car or the like to define an upper ceiling compartment disposed over a main storage compartment. The ceiling compartment includes a central bunker for receiving a cryogenic material, such as carbon dioxide snow, wherein the bunker is separated by short partition walls from a pair of elongated plenum chambers extending along both sides of the bunker. Cryogenic gas formed by sublimation spills over the partition walls for passage from the bunker into the plenum chambers, and for further passage from the plenum chambers through downflow ports in the panels into the underlying main storage compartment to refrigerate perishable items therein.

Abstract: A shipping container for shipping both a set of vessels to be maintained in a frozen state and a set of vessels to be maintained in an unfrozen state during shipment, using a single supply of pre-frozen refrigerant material. The container includes an insulated chest and three trays removably positioned within the chest. The chest has a refrigerant well with one tray positioned immediately adjacent to the well and containing the vessels to be maintained frozen. The two trays positioned away from the well contain the vessels to be maintained in an unfrozed, but yet refrigerated state. The shipping container further includes a storage member to hold items to be shipped with the vessels but not requiring freezing or refrigeration. The chest is sized to receive three kit containers which each contain three trays and a storage member, and the chest is closed with a removable insulated lid.

Abstract: Apparatus for freezing liquid-carrying pipes, with an annular casing having an inwardly open cross-section, with a supply line, provided with a valve, for supplying a refrigerant to the interior of the casing, which is improved in that the casing (1) has two parts (2,3) which can be directly fixed together at right angles to the casing axis and with end walls (4,6;7,8) kept spaced by a jacket wall (9,11) and that a carbon dioxide supply lance (43) with its end face (44) having an opening can be brought up to the connecting face of the inside edges (41) of end walls (4,6;7,8).

Abstract: A flexible cryogenic hose is comprised of an inner cryogenic tube surrounded by a concentric heat shield, a closed concentric chamber and an outer protective jacket. At normal ambient temperatures the chamber is completely filled with carbon dioxide gas. As cryogenic liquid is pumped through the inner cryogenic tube, heat is transferred from all structures within the hose, including in particular the carbon dioxide gas in the closed chamber, which runs the length of the cryogenic tube. As the carbon dioxide gas is cooled, it liquefies, thereby substantially evacuating the chamber. The chamber has sufficient structural rigidity to avoid collapse at normal atmospheric pressures. After the cryogenic hose is used, cryogenic flow ceases and the hose warms. In warming, carbon dioxide gas in the chamber gassifies and again refills the chamber.

Abstract: A transportable container for carrying refrigerated products in frozen (sub zero) or refrigerated (for example, 40.degree. F.) temperatures includes a structural container having an insulated outer shell with an access doorway. The upper portion of the container includes a transverse perforated baffle and positioned above the baffle are a pair of spaced apart canisters containing liquid refrigerant (CO.sub.2, for example). A gas or liquid feeder tube penetrates each bottle and communicates with an on/off valve. A feeder tube can draw liquid to dispense for cooling, or it can release gas and pressure within the canister to boil the CO.sub.2. When CO.sub.2 reaches its boiling point, the canister, its bracket, and the cold plate reach very cold temperatures to cool the cargo area. The gas is released through copper tubing over the cold plate to act as a method for convection. A temperature regulator valve dispenses CO.sub.

Abstract: A rapid freezing apparatus utilizes a flexible bag surrounding a cooling chamber for containing solid carbon dioxide formed in situ.

Abstract: An insulated refrigerated storage container apparatus comprises a plurality of wall members defining a generally rectilinear enclosure and including respective top, bottom, front, rear and opposing side wall members. An access opening is provided in the front wall and an access door mounted to the access opening for selectively closing the same. A refrigerant compartment is located interiorly of the enclosure adjacent the top wall thereof. Channels are provided for directing a flow of refrigerated fluid from the refrigerant compartment over and around top, rear and bottom portions of the interior of the enclosure so as to substantially surround an interior volume defined within the enclosure with refrigerated fluid. An exhaust vent is located at a lower portion of the container for exhausting excess air and spent refrigerated fluid from the enclosure.

Abstract: A frozen food container adapted for use with wheeled carts of the type used to provide food and beverage service to aircraft passengers comprising bottom, end, side and top walls formed from a thermally insulating material contained between an inner and outer shell, the top wall having an insulated lid formed in the forward portion thereof, and opposed shoulders extending along the exterior of the side walls to support the container within a wheeled cart for transport through the aircraft aisle to facilitate service of frozen food items to aircraft passengers.

Abstract: A method and system for delivering high pressure, subcooled liquid carbon dioxide. An insulated tank having a height greater than its internal diameter holds liquid CO.sub.2 to a depth of at least about 6 feet, and high pressure, subcooled liquid CO.sub.2 is delivered from a lower outlet of the tank. CO.sub.2 vapor is condensed in the upper region to maintain a desired high pressure, e.g., about 290-310 psi., at the top of the tank. By withdrawing liquid CO.sub.2 from an upper region in the tank, subcooling it by heat exchange and returning subcooled liquid CO.sub.2 to a lower region, a thermocline region is created at least 2 feet below the surface, and above which equilibrium high pressure liquid CO.sub.2 exists. Heat exchange is efficiently carried out during off hours using liquid carbon dioxide to chill the condensed refrigerant from an existing auxiliary mechanical refrigeration unit.

Abstract: Cooling by carbon dioxide. The apparatus comprises:as an expansion member, at least one appliance (5) for the expansion and separation of the solid and gaseous phases, which is interposed between the pipe (3) and the chamber (4) and which has a gaseous-phase outlet and a solid-phase outlet communicating with the chamber via a sealing means (10),a gaseous-phase recovery pipeline (15) connected to the gaseous-phase outlet of the appliance (5),a compressor (16) fed by the recovery pipeline (15),and a means (17) for liquefying the gaseous phase for the purpose of re-using it.Application for the deep-freezing of food products.

Abstract: A vented cold tank is provided and partially filled with a eutectic solution. CO.sub.2 snow forming structure is provided within the interior of the tank above the level of the eutectic solution therein and liquid CO.sub.2 injection means is provided in a lower portion of the tank below the level of eutectic solution and arranged to create circulation of the eutectic solution within the tank including generally opposite horizontal and generally opposite vertical component of movement of the solution within the tank. Further, structure is provided for communicating the CO.sub.2 snow forming means and the liquid CO.sub.2 injection means with the same source of liquid CO.sub.2 under pressure.

Abstract: The invention relates to a process and an apparatus for the adjustment of maintenance of a refrigerated atmosphere, in particular an atmosphere adjusted to goods stored in a refrigerating tank, in particular a refrigerating container, with the refrigerating requirement exclusively covered by the introduction of cold nitrogen from a supply of liquid nitrogen.According to the invention, the normally immobile atmosphere is forcibly circulated in arbitrarily selected time intervals or in time intervals determined by measured operating parameters (T, CO.sub.2 content, O.sub.2 content, humidity) during time intervals which are predetermined or determined by measured operating parameters.The temporary circulation of the atmosphere is effected by means of a blower actuated by a control means.

Abstract: A transportable container for carrying refrigerated products in frozen (sub zero) or refrigerated (for example, 40.degree. F.) temperature includes a structural container having an insulated outer shell with an access doorway. The upper portion of the container includes a transverse perforated baffle and positioned above the baffle are a pair of spaced apart canisters containing liquid refrigerant (CO.sub.2, for example). A gas or liquid feeder tube penetrates each bottle and communicates with an on/off valve. A feeder tube can draw liquid to dispense for cooling, or it can release gas and pressure within the canister to boil the CO.sub.2. When CO.sub.2 reaches its boiling point, the canister, its bracket, and the cold plate reach very cold temperatures to cool the cargo area. The gas is released through copper tubing over the cold plate to act as a method for convection. A temperature regulator valve dispenses CO.sub.

Abstract: A chamber for keeping perishable material, either liquid or solid, under refrigeration is provided with a tubular metal container that can be filled with pressurized liquid carbon dioxide. When the pressure in the container holding liquid carbon dioxide is dropped to atmospheric pressure, approximately half of the liquid flashes off as vapor and half becomes solid. The container is disposed along the top of the chamber so that refrigeration from solid carbon dioxide therein flows through the chamber by convection currents. Carbon dioxide vapor may flow from the container into the chamber to provide a protective atmosphere for the material therein.

Abstract: A container for transporting an accidentally severed limb 17 or other body part and keeping it cool to aid the success rate of replantation surgery comprising a suitcase-like openable container 2 made of aluminium sheet 4 with a heat insulating covering 5. To maintain the temperature of the container between 2.degree. C. and 6.degree. C., a cylinder of carbon dioxide 19 is mounted in a holder 9, 18 on the outside of the container and has its shut-off valve 20 connected to an injector nozzle 23 in the container. Carbon dioxide discharged by the nozzle 23 produces dry ice in the container 2 to cool it. The flow of gas through the nozzle 23 is controlled by a thermostatic device which includes a spring 24 made of a shape-memory alloy which allows the nozzle 23 to be closed at temperatures below 2.degree. C. but which regains its strength at a temperature of 6.degree. C. to open the nozzle when the inside of the container has warmed up again to this temperature.

Abstract: A process and apparatus for bringing CO.sub.2 from a storage tank wherein it is stored at a medium pressure and below 0.degree. C. (e.g. -20.degree. C. and 20 bars pressure) to a high pressure such as 80-130 bars, without utilizing any pump operating below 0.degree. C. The build-up of ice on such a pump is thus avoided. To do this, liquid from the tank is caused to completely fill by gravity an intermediate vessel. Then the vessel is heated to about ambient temperature; and while maintaining such temperature (e.g. by means of resistor 16), the liquid in the vessel is subcooled by compression in FIG. 1 or by cooling water in FIG. 2, and conveyed to the inlet of the high pressure pump.

Abstract: Large quantities of CO.sub.2 snow are provided by a system and method which utilizes two reservoirs which maintain at least about 4500 pounds of CO.sub.2 at about its triple point, a substantial portion of which contains solid CO.sub.2. A first such reservoir subcools high pressure liquid CO.sub.2 flowing therethrough and permits efficient production of CO.sub.2 snow. A second such reservoir assists in cooling and condensing CO.sub.2 vapor recirculating through the system, as well as in efficiently obtaining CO.sub.2 being delivered to the system from an outside source.

Abstract: A plurality of work stations may be cooled and temperature-controlled with subcooled liquid CO.sub.2 without a plurality of mechanical units for cooling CO.sub.2 and high capital costs resulting therefrom. The system includes a plurality of spaced-apart enclosures to be cooled, each enclosure having an associated tank containing subcooled liquid CO.sub.2 to be directed into the enclosure for cooling it and then to exhaust. The associated tanks are connected to a source of high pressure CO.sub.2 such as a large storage vessel which supplies CO.sub.2 for the associated tanks and for cooling the associated tanks as by expanding liquid CO.sub.2 in the vicinity of the associated tank. After expansion, CO.sub.2 vapor is directed to a reservoir or directly back to the storage vessel via a compressor. The reservoir contains CO.sub.2 slush and collects vapor CO.sub.2 used in the cooling process of a multiplicity of duplicate associated tanks, thus serving as a sink for the collection of CO.sub.

Abstract: The apparatus comprises a plurality of modular containers (2) each receiving a charge of products. Liquid CO.sub.2 is injected into each container under the control of a thermostat (28). The excess gases are collected in a single manifold (5), heated in a vessel (3) and then discharged through calibrated discharging means (7). The invention is particularly suitable for the cooling of food products.

Abstract: A compact hydride absorption refrigeration system with few moving parts for 10.degree. Kelvin operation is disclosed and comprises liquid hydrogen producing means in combination with means for solidifying and subliming the liquid hydrogen produced. The liquid hydrogen is sublimed at about 10.degree. Kelvin. By using a symmetrical all hydrogen redundant loop system, a 10.degree. Kelvin refrigeration system can be operated for many years with only a fraction of the power required for prior art systems.

Abstract: A pair of CO.sub.2 snow forming nozzles are provided within a tank for receiving CO.sub.2 snow and the nozzles are mounted in an upper portion of the tank with their outlet ends directly opposing each other and spaced apart approximately 121/2 inches. A supply of liquid CO.sub.2 at approximately 300 psi is communicated with the inlet ends of the nozzles for simultaneous discharge of CO.sub.2 gas from the nozzle outlet ends and opposing impact of the discharges of CO.sub.2 from the nozzle outlet ends in an impact area disposed centrally between the nozzle outlet ends. In addition, the liquid CO.sub.2 is communicated with the inlet ends of the nozzles through a supply line therefor constructed of good heat transfer material and including an intermediate length portion passing centrally through the area of opposing impact of the discharges of CO.sub.2 from the nozzle outlet ends, thereby chilling the supply line to an extent sufficient to reduce the temperature of the liquid CO.sub.

Abstract: The invention concerns the cooling of a viscous product. The product placed in a vessel 30 is cooled by a rotary pot 8 in which is generated, by sleeves 20 and 21, a deposit of carbonic acid snow 40. Application in the cooling of food products such as clear soups, thick soups, sauces, creams, pastes, gelled products, etc.

Abstract: Process and Device for heat removal from the effective area of a cooling container with the application of dry-ice as cooling agent, where a refrigerant (e.g. FREON) is circulated in a closed pipe system.According to the construction and degree of charge the gravity cooling system (thermosyphon) or evaporation principle with natural circulation is used to take up the heat from interior space and to supply it to dry-ice as heat of sublimation.The systems of heat transfer are arranged in such a way that even for the inclined cooling container, e.g. at the time of aircraft take-off, at least half of the diagonally arranged heat transfer systems in the interior part are fully active to provide sufficient cooling.

Abstract: A hyperbaric storage device has a walled inner and outer containers, a compressed gas supply contained within the device, a conduit from the gas supply to the inner container, a control valve for the conduit responsive to pressures above and below a superatmospheric pressure valve for closing and opening the valve.

Abstract: A freezing agent for maintaining supercold temperatures. Solid carbon dioxide is impregnated with liquid nitrogen so that the liquid nitrogen diffuses through the lattice of crystals making up the solid carbon dioxide. The liquid nitrogen maintains the solid carbon dioxide at supercold temperature for a long period of time. The nitrogen-impregnated solid carbon dioxide can be in the form of nuggets for lining or packing a cooling container, and a frozen biological sample can be maintained at supercold temperature within the container for many hours.

Abstract: An apparatus for a non-mechanical refrigerated vehicle is disclosed. A rail car (10) has an enclosed storage area (17). A bunker (20) is positioned proximate the ceiling (16) for containing solid refrigerant flakes. Loading manifold (50), supply manifold (70) and the nozzle (75) transfer and convert the liquid CO.sub.2 into the solid refrigerant flakes that are directed into the bunker (22). A mesh screen (30) allows for vapor to exit the bunker (22) to the storage area (17). The screen mesh (30) is positioned proximate the first sidewall (11). The sidewalls (11) and (12) have channels (34) and the floor strips (44) have air flow channels (44e) for the flow of air, including vapor. When the refrigerant flakes sublimate in the bunker (22), the vapor flows from the bunker (22) out the screen mesh (30), down the channel (34) of the first sidewall (11), across the air flow channel ( 44e) and up the channel (34) of the second sidewall (32), all by convection.

Abstract: A method for the continuous treatment of poultry carcasses. The poultry carcasses are successively singed, cooled, deboned, minced, shaped and packaged. Prior to singeing, the carcasses are injected with carbon dioxide snow to prevent the development of germs during singeing. The mincing, shaping and packaging steps are carried out in an enclosure in which carbon dioxide snow is introduced so that the temperature is maintained at about 0.degree. to -4.degree. C.

Abstract: A passive temperature control shipment container is provided having a central chamber surrounding a sample or specimen wherein the central chamber has two conductive walls, one of which is in contact with a heat source and one with a heat sink to provide a specified temperature change profile and to maintain a specified temperature time relationship in the shipping container.

Abstract: The vent line of a space-borne solid subliming cooler is formed to provide a heat radiator which radiates much of the heat losses otherwise parasitically conducted back to the cooler thereby permitting the use of certain high heat capacity cryogens at operating and working temperatures requiring very low operating vapor pressures but without as much parasitic heat conduction loss as is associated with conventionally vented solid subliming coolers.

Abstract: A refrigerated transport having an insulated enclosure and including a cryogen reservoir, e.g., high-pressure liquid cryogen or solid CO.sub.2. A plurality of thermosyphons associated with the walls and floor of the enclosure adjacent the interior skin intercept heat attempting to enter the enclosure. An intermediate heat sink draws the intercepted heat from the upper portions of the thermosyphons. The temperature of the heat sink is thermostatically controlled in a manner that the rate at which heat from the heat sink is absorbed by the cryogen is regulated to maintain the heat sink within a desired temperature range such that the thermosyphons will in turn maintain the enclosure and its product load at the desired subambient storage temperature.

Abstract: Process for quick freezing and conditioning of individual products, and apparatus to practice this process. The process is characterized in that it consists essentially in treating small individual quantities of different products in modular indivdual quick-freeze chambers (1) fed with cryogenic gas and connected each to a quick-freeze tunnel (3) so as to provide in the latter a low temperature, and in treating larger quantities of product pieces in the tunnel (3), provided with a conveyor belt (4) and which is also fed with cryogenic gas, in evacuating the residual warmed gas obtained from the interior of the tunnel (3), in packaging the products leaving the tunnel in insulating packaging disposed in a receiver (6) mounted at the outlet of the tunnel (3), or in filling the packaging with products issuing from a chamber, then in surrounding the assembly of products disposed in the packaging with a cryogenic product, and closing the packaging.

Abstract: A snow horn device for dispensing carbon dioxide snow in the form of a ribbon of substantially uniform width includes a conduit into which liquid CO.sub.2 is expanded to form solid and gaseous carbon dioxide which in turn is directed as a stream into a curved horn section of increasing, rectangular cross sectional area. The gaseous and solid CO.sub.2 stream is deflected to the outer curved portion of the horn section, and ambient atmosphere is introduced therein to create a pressure differential that causes solid CO.sub.2 to be spread evenly along the outer curved section. Alternately, the inner and outer curved horn sections are warmed by a flow of liquid CO.sub.2 which prevents solid CO.sub.2 from sticking to the curved surfaces. Solid carbon dioxide is discharged from the outlet of the horn section onto a moving surface in the form of a ribbon having a width approximately equal to the width of the horn section and at a uniform depth.

Abstract: A self contained refrigerated shipping or storage container utilizing liquid carbon dioxide is disclosed. The container utilizes a network of liquid containing units arranged to allow maximum useful storage space with maximum cooling. The container is insulated and has four walls, at least one of which has at least one access door therein, a floor and a roof, with a pressurized liquid carbon dioxide reservoir having a workable heat exchange relationship with the interior of the container. The reservoir includes a gaseous space with a vent from the space having a pressure relief valve therein adapted to maintain a substantially constant pressure in the reservoir such that the temperature of the liquid carbon dioxide in the reservoir is controlled.

Abstract: A cooling device, particularly for heat protective suits, comprises, a housing having a bottom with a heat exchanger surface exposed therein, and a solid refrigerant, such as dry ice, overlying the heat exchanger surface. The ice is preferably biased toward the heat exchanger surface and a flexible intermediate layer is disposed between the dry ice and the heat exchanger surface. The flexible intermediate layer is saturated with a fluid, such as one which remains liquid to below the sublimation point of the solid refrigerant. The heat exchanger surface is advantageously connected through connecting lines and a pump to circulate it through various passages in the protective vest or suit.

Abstract: A vertically elongated hollow housing including opposite generally parallel side and end walls is provided and closed at its top by a top wall. CO.sub.2 snow forming structure is disposed in a upper portion of the interior of the housing and a bottom wall structure closes the lower portion of the housing. The bottom wall structure includes an elongated horizontally disposed inverted V-shaped wedge of sharply tapered configuration extending between the end walls of the housing and the wedge is functional to split the lower portion of a quantity of snow disposed within the housing above the wedge and to force the lower portions of the quantity of snow into full surface-to-surface heat transfer relation with the inner surfaces of the lower portions of the side walls of the housing horizontally aligned with and opposing the wedge as the quantity of snow sublimes.

Abstract: An apparatus for facilitating assembling a length of flexible tubing on a component part which avoids the use of sealing solvents yet affords a secure placement of the tubing thereon. The apparatus and method assures a secure fitment by stretching the tubing to a predetermined dimension which is larger than the outside dimension of the portion on which the tubing is to be placed on the component part, and while in such a position the tubing is temporarily frozen by means of a coolant. An important feature in stretching the tubing to the enlarged dimension is in assuring that it is done in a uniform manner and that the stretched walls are substantially parallel to each other. This is effected by utilizing a parallel motion of jaw members which are placed within the tubing to stretch it to its expanded state.

Abstract: A device for dispensing carbon dioxide snow in the form of a ribbon includes a conduit into which liquid CO.sub.2 is expanded to form solid and gaseous carbon dioxide which in turn is directed as a stream into a curved horn section of increasing, rectangular cross sectional area. The gaseous and solid CO.sub.2 stream is deflected to the outer curved portion of the horn section and ambient atmosphere is introduced therein to create a pressure differential that causes solid CO.sub.2 to be spread evenly along the outer curved section. Solid carbon dioxide is discharged from the outlet of the horn section onto a moving surface in the form of a ribbon having a width approximately equal to the width of the horn section and at a uniform depth. Ribbons of such solid carbon dioxide may be formed on conveyor belts of freezing tunnels to enable refrigeration to be applied to the underside of items placed on such ribbons of CO.sub.2 snow.

Abstract: A carbon dioxide snow generator is disclosed which has a purge conduit for controllably delivering a blast of pressurized fluid at the inner surfaces of the generator to dislodge and remove any residual or clogging deposits of carbon dioxide snow. A vapor loop for such a generator is also disclosed which provides an initial blast of relatively warm carbon dioxide gas at startup which gas entrains and removes any residual liquid before it can freeze in the apparatus.

Abstract: The invention is an improved apparatus for the removal of sodium carbonate from cyanide plating baths. The method involves the precipitation of sodium carbonate by the effect of cooling the cyanide plating bath liquid. A container is submerged in the solution with the container opening extending above the plating bath solution level. The container is filled with dry ice and water which produces a temperature of approximately zero degrees centigrade inside of the container. The solution adjacent to the exterior of the container is cooled so that excess sodium carbonate is precipitated as a crystalline deposit. After a desired interval, the container is removed with the encrustation of sodium carbonate for disposal.

Abstract: A cabinet cooler or freezer which efficiently utilizes cryogenic refrigeration either with or without mechanical refrigeration. The freezer intermittently freezes relatively large batches of food by efficiently utilizing the natural expansion effect of a liquid cryogen, in combination with mechanical circulation by blowers, to create an overall circulation that efficiently removes heat from the food. A secondary circulation effect is induced, in a manner similar to the operation of a jet pump, which amplifies the circulation and allows CO.sub.2 to be employed as the cryogen with modulating valve control to achieve uniformly low temperature throughout the cabinet without snow build-up on the cabinet bottom. Some cabinet versions create a cyclonic circulation pattern about a vertical axis that is particularly effective.

Abstract: A cabinet cooler or freezer which efficiently utilizes cryogenic refrigeration either with or without mechanical refrigeration. The freezer intermittently freezes relatively large batches of food by efficiently utilizing the natural expansion effect of a liquid cryogen, in combination with mechanical circulation by blowers, to create an overall circulation that efficiently removes heat from the food. A secondary circulation effect is induced, in a manner similar to the operation of a jet pump, which amplifies the circulation and allows CO.sub.2 to be employed with modulating valve control to achieve uniformly low temperature throughout the cabinet without snow build-up on the cabinet bottom. Some cabinet versions create a cyclonic circulation pattern about a vertical axis that is particularly effective.

Abstract: The temperature of a product which is being chilled in a blender by introducing carbon dioxide in solid and gaseous form into the blender is controlled by sensing the power drawn by the drive motor coupled to the impeller. The power drawn by the motor is sensed and analyzed and, upon reaching a predetermined value, the introduction of CO.sub.2 into the blender is terminated. As the product is chilled by contact with CO.sub.2 in the blender, the viscosity of the product will increase, which in turn, increases the power drawn by the motor. Variations in line voltage supplied to the motor and changes of the initial temperature of the product being chilled do not affect the final temperature to which the product may be accurately chilled.

Abstract: In a pressure vessel of the type used for processing a product with a liquid cryogen such as the impregnation of tobacco with liquid carbon dioxide for expansion thereof, a withdrawal door, pivotally hinged to open to permit gravitational discharge of the processed product, includes a grating to support the product in the vessel when the door is closed. A wire screen mesh is disposed on the grating to permit gaseous and liquid cryogen to pass therethrough while substantially preventing product from passing therethrough. A holding apparatus includes means for securely holding the screen fixed relative to the grating at the periphery and interior surface portions of the screen, the apparatus preferably including a gridded structure for minimizing stretching and tearing of the screen during discharge of the processed product from the vessel.

Abstract: A cabinet is provided for containing items to be maintained in a cooled state and includes a hollow insulated housing having upstanding side walls and top and bottom walls closing the upper and lower ends of the housing. An inclined baffle is mounted within an upper portion of the housing and is constructed of a material having good heat transfer properties. The baffle defines a first closed heat absorbent material receiving chamber thereabove and a second cooled items receiving chamber therebelow within the housing. The lower marginal portion of the baffle terminates substantially against the inner surface of one side wall of the housing and the cabinet includes first and second access means opening into the interior of the first and second chambers from the exterior of the cabinet.

Abstract: Compressors are utilized in an apparatus for treating a product such as tobacco with a liquid cryogen, such as carbon dioxide for removing vapor from a processing chamber and recompressing the vapor to facilitate its return to the cryogen system. When the compressors do not receive a supply of cool vapor from the processing chamber, the compressor temperature rises and the pressure drops. When the pressure reaches a predetermined minimum setpoint, the compressors are interconnected by means of a remotely controlled valve to a vessel containing cryogen vapor at a pressure greater than the pressure at the compressors. A supply of cool cryogen vapor thus flows to the compressors to reduce the temperature, thereby allowing continuous operation of the compressors during periods in which cryogen vapor flow from the processing chamber is interrupted or delayed.

Abstract: A rotary freezer for cooling resilient golfball centers to a uniform, substantially rigid state is provided with a dispenser to permit dispensing of rigid centers in one-at-a-time fashion from a large batch of frozen centers in the freezer at a rate indepenent of the residence time. As the freezer drum rotates, paddles on the inner circumference serve to lift randomly-selected centers from the batch to a predetermined height for gravity loading onto an inclined rack forming a part of the dispenser. Centers on the rack are arranged in a rectilinear series leading to an outlet port where a metering assembly controls dispensing of the centers from the drum in one-at-a-time fashion at a rate determined by the operator. A gravity conveyor exterior of the freezer drum transports each dispensed center from the outlet to a work station where the winding process is to be initiated before the center returns to its resilient state.

Abstract: A sublimation refrigerator employs a thermally insulated outer housing having a pivotable top. A smaller insulated dry ice chamber is adapted to be supported centrally within the container as is a separate insulated freezer compartment having a removable top. A first set of serpentine cooling coils are supported in the interior side walls of the main insulated container and in the side walls of the freezer compartment. One end of each of these coils connects to the dry ice chamber. A bubble type visual flow indicator having a transparent window is supported on the exterior of the main container. The output ends of both the freezer coil and the cooler coil connect to the visual indicator through manually adjustable flow control valves. The output of the visual indicator vents to atmosphere. In normal use the valve at the output of the freezer coil is opened allowing free flow of gas sublimating from the dry ice through the freezer coil so that a very low temperature is attained within the freezer.