Abstract: A video camera or other scanning device is employed to monitor the loading with articles to be frozen of an endless belt which passes through a freezing apparatus so as to freeze such articles typically by contact with liquid nitrogen or its cold vapor. The video camera is associated with electronic circuits that generate a signal representative of the belt loading and compare it with a signal representative of an optimum belt loading. If the difference between the signals is greater than a chosen threshold the belt speed is adjusted so as to reduce or eliminate the difference. By this means an improvement is made possible in the efficiency with which the liquid nitrogen is utilized.

Abstract: The tunnel comprises a tube (1) in which are stacked parts (A) to be cooled, and an intermediate chamber (7) which surrounds the tube and around which is disposed a heat exchanger (3). Liquid nitrogen is vaporized upwardly in the exchanger, redescends in the chamber (7) and rises in the tube (1). The supply of liquid nitrogen is controlled by a temperature probe (17). Application in the cold fitting of parts in the mechanical industry.

Abstract: A cabinet freezer efficiently utilizes a liquid cryogen refrigerant in conjunction with a spiral conveyor which conveys a product load through a temperature gradient within the freezer. The freezer has a lower inlet and an upper outlet for the conveyor and food load thereon. The escape of cryogen vapors created in the freezer from the liquid cryogen is controlled such that at least about 80% of the vapors exit through the upper outlet which is at the warmest zone established as a part of the temperature gradient in the freezer.

Abstract: A Clinker cooler has a stationary tubular body (4) with a material inlet (3) connected to a kiln (1) and a material outlet (5). Material (18) is repeatedly raised into the path of cooling air from a fan (7) by blasts of air from a row of blasters (8).

Abstract: An apparatus for transporting and at the same time cooling sensitive and perishable goods such as sliced vegetables by means of an auger including a transport screw disposed in a trough-like housing provided with an insulating jacket and an insulated lid arranged in spaced relationship from the transport screw, wherein the transport screw has coils with bulged rounded outer edges which are spaced from the trough housing wall and wherein a coolant injection pipe is disposed in the space between the transport screw and the lid of the trough for introducing a cooling fluid into the trough while the goods are moved therethrough thereby providing direct contact of the cooling fluid with the large surface area of the goods to be cooled for efficient and rapid cooling of the goods.

Abstract: A method and apparatus is provided for efficiently solidifying solvent-refined coal whereby the hot solvent-refined coal in liquid form is contacted in a cooling zone with dry, inert, heat absorbent particulate solids within a rotating structure. The liquid solvent refined coal is solidified upon the particulate solids, separated by abrasion and friction within a separating zone, and the particulate solids are cooled and recycled back into the cooling zone for contact with a fresh supply of liquid solvent refined coal.

Abstract: A method of freezing perishable foods including the steps of causing one surface of a heat conducting container to contact cooled brine or a liquified gas of a low-boiling point, and keeping an object to be frozen in contact with the other surface of the heat conducting container. Thus, the freezing of the food proceeds only from the surface contacting the heat conducting container.

Abstract: The present invention relates to an improved cooling chamber for the manufacture of high-pressure reinforced hose. Hose to be treated is passed through a tubular passageway in the cooling chamber where it is contacted with a cryogenic fluid. A portion of the cryogenic fluid is passively recycled via a recycle loop to provide further cooling within the tubular passageway. An end seal is attached to one end of the cooling chamber to prevent moisture build-up and freezing inside the chamber.

Abstract: The present invention relates to an improved cooling process for the manufacture of high-pressure reinforced hose. Hose to be treated is passed through a cooling chamber where it is contacted with a cryogenic fluid which totally flashes to a cold gas upon contact with the hose. A portion of the cold gas is passively recycled to provide further cooling. One end of the cooling chamber is sealed to prevent moisture build-up and freezing inside the chamber.

Abstract: Eviscerated poultry is conveyed upon a shackle through a refrigerated space in a compact configuration for a time sufficient to chill birds so as to cause them to self-retain the compact configuration when delivered to a bird packaging station for packing in the same configuration. The shackle itself has a basket pivotably mounted to a lower portion of a hanger bar and a canopy mounted to an upper portion of the bar.

Abstract: A process is provided for carrying out the cryogenic cooling of a material which comprises introducing material to be cooled into an elongated cryogenic tunnel housing on means for conveying said material from an inlet end to an outlet end, spraying liquid cryogen onto said material as it travels through said tunnel at a position proximate said outlet end, passing vapor or gas derived from said liquid cryogen in counter-current flow over said material passing through the tunnel, removing from said tunnel at a position proximate said inlet end an exhaust comprising said vapor or gas and atmospheric air entrained thereby through said inlet end, determining the rate of flow of the exhaust and the content of molecular oxygen in said exhaust, and calculating from the rate of flow of the exhaust and its oxygen content the rate of consumption of said liquid cryogen.

Abstract: An apparatus for heating or cooling sealed food pouches, another apparatus for moving the same and a third apparatus adapted to transfer the pouches are disclosed. The three apparatuses are designed to function as an integrated food pouch handling system, but may also be used separately. The first apparatus consists of a large bath partially filled with circulating hot or cold liquid, following a course in which whirlpools are created. The food pouches are placed in the bath and are carried by the moving liquid until they have attained the desired temperature. The second apparatus consists of a conveyor mounted on a cart. The conveyor is tiltable so that one end thereof can be placed in the bath to automatically retrieve the food pouches. The third apparatus is a large vat to receive the food pouches placed therein by the conveyor.

Abstract: When cooling hot metal strip, it is known to employ headers which apply continuous curtains of water across the width of the strip. The headers above the strip are inclined to each other so that the curtains extend across the width of the strip and are spaced apart horizontally by a greater distance at one edge of the strip than at the other edge.

Abstract: An apparatus for disintegrating lumps of boiled rice while cooling and freezing, comprising a cooling chamber and a freezing chamber through which boiled rice is caused to pass being carried on a mesh conveyor and thereby being cooled and frozen to a temperature from +10.degree. C. to -30.degree. C., and one or plurality of disintegrators disposed above and across the belt conveyor each comprising a rotary comb and a stationary comb both having a plurality of comb teeth disposed such that the teeth of the opposing combs are meshed with each other. In a preferred embodiment, the stationary comb of the disintegrator at the downstream of the mesh belt conveyor is disposed spaced apart from the belt conveyor by such a gap between the lower end of the comb teeth and the upper surface of the belt conveyor as allowing to pass only the individually disintegrated rice grains to pass therethrough.

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: The cable C to be stripped is wound with non-touching coils and crossed layers of cable onto a drum 6 having a perforated core 10 rotatively mounted in a thermally insulated container 1. By injecting into the container liquid nitrogen under the control of a temperature sensor and by circulating the gases contained in the container through the core of the drum and the cable coils, the whole of the cable is cooled down to a temperature at which the plastics coating and, as the case may be, the outer steel sheath of the cable become brittle. The cable is then unwound and, when it has left the container, it is subjected to various mechanical stresses. The stripped cable is finally wound onto a take-up reel 3. Application in the recovery of scrap in the manufacture of power cables of large diameter and recovery of used electric cables.

Abstract: The beverage cooling device of the present invention comprises an ice receptacle having an ice compartment therein and having an open upper end. An electric motor having an outlet shaft thereon is mounted in a track on the exterior of one of the walls of the receptacle and is free to move upwardly and downwardly within the track. The output shaft extends through a shaft opening in the side wall of the ice receptacle, and includes a suction cup for detachably grasping the container for the beverage. Actuation of the electric motor causes the beverage container to rotate and to frictionally engage ice within the ice receptacle.

Abstract: A packing plant by-products chiller includes an elongated tank having an inlet end for introducing fresh animal by-products and an outlet end for removing chilled by-products. The tank is rotatably supported on a set of trunnion wheels and is rotated by a chain and sprocket assembly operatively connected to a motor. A liquid coolant supply line from a coolant source introduces low temperature coolant into the tank. An elongated trough is positioned beneath the tank for receiving warmed coolant which drains from the tank through a plurality of apertures therein. A pump is operatively connected to the trough for recirculating the coolant back to the coolant source.The method of chilling fresh animal by-products comprises introducing the by-products and liquid coolant from the coolant source into the chilling tank located at the slaughter location and rotating the tank such that the by-products therein are tumbled for complete exposure to the coolant.

Abstract: A packing plant by-products chiller includes an elongated tank having an inlet end for introducing fresh animal by-products and an outlet end for removing chilled by-products. The tank is rotatably supported on a set of trunnion wheels and is rotated by a chain by sprocket assembly operatively connected to a motor. A liquid coolant supply line from a coolant source introduces low temperature coolant into the tank. An elongated through is positioned beneath the tank for receiving warmed coolant which drains from the tank through a plurality of apertures therein. A pump is operatively connected to the through for recirculating the coolant back to the coolant source. The method of chilling fresh animal by-products comprises introducing the by-products and liquid coolant from the coolant source into the chilling tank located at the slaughter location and rotating the tank such that the by-products therein are tumbled for complete exposure to the coolant.

Abstract: A method and apparatus are provided for rapidly and efficiently cooling a flow of a food substance such as ground chicken meat while simultaneously conveying the food substance along a relatively short, upwardly inclined travel path that is defined by an inner chamber of an elongate housing assembly. A power driven auger extends along the travel path and is journaled by the housing assembly for rotation within the inner chamber. An inlet hopper is provided for introducing a flow of relatively warm food substance into a lower end region of the inner chamber. A discharge spout is provided for discharging a cooled flow of the food substance from an upper end region of the inner chamber. Cooling of the food substance as it is conveyed along the travel path is effected by providing the housing assembly with a refrigerant chamber that surrounds but is segregated from the inner chamber.

Abstract: A method for continuously producing pop-shaped frozen confections at line speeds exceeding 20 cycles per minute is disclosed. A conveyor system for transporting pop-shaped metal molds is provided. The molds are filled with a flowable confection so that the top portions of the molds are left unfilled. The molds are then transported into a freezing zone to partially freeze the contents. A stick is inserted into the partially frozen contents of each mold. Next, a liquid cryogen, such as liquid nitrogen, is added to each mold to cover the exposed surface of the material. The liquid cryogen is then vaporized and the molds are removed from the freezing zone. Then, the completely frozen, pop-shaped confections are removed from each mold and immersed in a water bath to form an encapsulating ice shell thereon. The ice-coated frozen confections may be subsequently packaged.

Abstract: A steel strip (10) is conveyed through a galvanizing bath (20) of molten zinc, a zinc coating weight control device (12), and a minispangle box assembly (16). The steel strip emerges from the zinc coating weight control device (12) with a non-uniform temperature distribution across its width in which it is warmer in the center and cooler at its edges. A differential, pre-cooler assembly (18) cools the steel strip selectively and non-uniformly across its width in a manner which is complimentary to the temperature distribution thereacross. In this manner, the steel strip exits the pre-cooler assembly (18) and enters the minispangle box assembly (16) with a more uniform temperature distribution. This results in a more uniform minispangle appearance on the strip (10) as it exits the minispangle box assembly (16). The pre-cooler assembly includes a plurality of nozzle pairs (32a, 32b; 34a, 34b; 36a, 36b; 38a, 38b).

Abstract: An apparatus for continuously freezing liver pieces which comprises a freezing box having an inlet and an outlet, a conveyor movable from the inlet to the outlet of the freezing box and having a mesh belt, a number of nozzles provided laterally through the box at the upside of the mesh belt of the conveyor for blowing gaseous helium, a supplying guide portion formed at the head of the inlet at the upside of the mesh belt for supplying and placing the liver pieces, a rotatable roller journaled at the striking-off and exhausting portion disposed inside the striking-off and exhausting portion at the head of the outlet at the upside of the mesh belt in an outside contacting state laterally of the mesh belt, the roller having a number of striking-off projections projected from the surface thereof for striking-off the frozen liver pieces on the mesh belt by the insertion of the projections into the mesh belt.

Abstract: Controlled freezing of a material (12) is accomplished by positioning an aliquot of the material (12) upon one surface (26) of a longitudinally extending substrate (14). First (30) and second (36) bases are provided each having heat transfer surfaces (32,40) which are adapted to sit in heat transfer relation with the other surface (24) of the substrate (14). The temperature of the first base (30) is controlled to be above the freezing temperature of the material (12). The temperature of the second base (36) is controlled to be below the freezing temperature of the material (12). The substrate (14) is moved longitudinally across the first base (30) in the direction of second base (36) while maintaining heat transfer relation of both bases (30,36) with the first surface (24) of the substrate (14). The frezzing rate of the material (12) is closely controlled and frozen material (12) can be produced in a continuous process.

Abstract: An exhaust system for a cryogenic freezer is set forth wherein the system senses the temperature of an aperture in the freezer to detect any outward passage of cryogenic vapors and based upon that sensing, controllably operates an exhaust fan to remove such cryogenic vapors.

Abstract: A method of and apparatus for controlling the flow of cooling water to the top of a hot metal strip on a runout table is disclosed. Cooling water is continuously discharged from nozzles in spray bars above the strip and cooling is controlled by selectively diverting the water from selected ones of the spray bars to control the volume and location of the water applied. Movable deflector plates are mounted adjacent predetermined spray bars and actuators are provided to selectively move the deflector plates to deflect water into a fixed trough to be diverted from the top of the strip.

Abstract: A tunnel refrigeration device includes frame members mounted substantially adjacent to an endless conveyor belt which is utilized to pass products to be refrigerated through the tunnel. The frame members are provided with apertures therein and fan means are mounted in one or more of the apertures so as to pass the tunnel atmosphere into the space between the upper and lower runs of the conveyor belt. Apertures are juxtaposed with each frame mounted fan to enable the tunnel atmosphere passed into this space to be removed therefrom and recirculated upwardly in the tunnel by means of the top mounted fans. Refrigeration is provided to the underside of products on the conveyor belt and the effective capacity of the tunnel may be increased by increasing the capacity of the top mounted fans.

Abstract: In a method of freezing a liquid such as cream, a continuous, pulsating stream of liquid is dispensed from nozzles onto a stream of liquified gas flowing along downwardly inclined channels provided by a trough. The liquid forms itself into discrete spheroidal bodies, a substantial number of which have a larger cross-sectional area than that defined by the outlet of each nozzle from which they are dispensed. The bodies are carried by the liquified gas along the channels and at least their peripheries are frozen by the time the bodies reach the downstream end of the channels. Freezing may be completed by gas cooling. The bodies are then separated from the liquified gas.

Abstract: The present invention is an improved process for cooling cement which comprises injecting liquid nitrogen into a pneumatic transport line used to convey the cement.

Abstract: A product such as ground meat is efficiently chilled in a blender device having an open top. Liquid carbon dioxide is introduced into the blender at a location below the surface of the product to thereby form solid and gaseous CO.sub.2. Mixing elements such as a ribbon screw or the like are operated to pass the product in a countercurrent relation to the carbon dioxide introduced into the blender thereby chilling the product and causing the resulting CO.sub.2 gas to rise along one wall of the blender. Deflector means are provided along such wall to direct the rising vapor toward an exhaust plenum located above the open top of the blender.

Abstract: Products to be frozen are conveyed through an insulated horizontal tunnel having a plurality of individual cooling zones, each equipped with a radial fan rotating in a horizontal plane. Cryogenic liquid refrigerant is sprayed into one or more of the cooling zones in the central region of the tunnel, upwardly into the rotating fans and the thus vaporized refrigerant caused to flow in a downward direction in a recirculating pattern into contact with the conveyed products by vertical partitions between contiguous zones. The vaporized refrigerant flows from the supercold zone of liquid introduction beneath the edges of the partitions in two directions, outwardly towards the opposite ends of the tunnel in substantially equal amounts.

Abstract: In the manufacture of moulds or mould cores, refractory sand, a resin binder and a catalyst are passed into a mixer to form a freeflowing mixture from which the moulds or mould cores are made. As the sand is fed into the mixer it is cooled by contact with an atmospheric gas in liquid or solid state or the cold vapour of such a gas so as to keep the temperature of the sand as it enters the mixer below that at which the resin cures. To enable the sand to be delivered below a chosen temperature from a quarry to a foundry where the sand is used, the sand after quarrying and drying is fluidized by air, an atmospheric gas in liquid or solid state being introduced into the fluidizing air so as to lower its 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: The temperature actuated valve comprises a thermally more sensitive valve stem than the valve housing. The stem expands at a faster rate and causes vapor entering the valve to be gradually vented through an orifice of gradually increasing area as the temperature of the gas increases. It has application as a cryogenic phase separator valve which allows any cryogen vaporized in a cryogen delivery system to be automatically vented from the valve and to allow for an even flow of liquid to the spray nozzles and onto products of cryogenic freezing tunnels.

Abstract: A method and device for cooling molds circulating in a horizontal plane, in which siphon action is used to pass cooling liquid from a top gutter through the molds. In this way the whole cooling system is becoming constructively simplified, such that production speeds can be increased, with the consequent greater length of the cooling system, but without its becoming unduly complicated. This effect is realized irrespective of the nature of the machine or the number of molds.Method and device are especially advantageous when applied with the manufacture of plastics tube, more particularly yet with the manufacture of plastic corrugated tube.

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 dual cooling tunnel arrangement for cooling viscous heated fluid foodstuffs in flexible bags. The flexible bags containing the heated fluids are received on pivoted wire carriers which are driven by an endless chain through an upper cooling tunnel in a first direction and returned through a second cooling tunnel in the opposite direction. In each cooling tunnel, a cooling water spray is directed on the bags in the carriers as the carriers are slowly rocked, causing the fluid in each bag to flow to different areas of the bag, altering its shape, to produce enhanced heat transfer rates and a more uniform temperature distribution throughout the fluid during cooling.

Abstract: A continuously controlled process for cooling a material to within a desired temperature range as the material moves along a path, especially suitable for situations in which the amount of material being cooled is unknown. The material is first contacted with a known amount of cooling liquid, e.g., water. The temperature of the water (or steam) is measured after contact with the material, and this information is then used to determine the amount of additional cooling required. An embodiment utilizing the process to cool calcined coke in a rotary cooler is described.

Abstract: In a process for cooling and fluidizing a bed of particles by passing a cryogen through the bed, said bed being first cooled to a desired operating temperature, the improvement comprising:(a) admixing a liquid cryogen and an inert gas, said gas being at ambient temperature, at a point external, but proximate, to the bed to provide a mixture of liquid cryogen and gas at a temperature sufficiently low to maintain the bed at about the desired operating temperature;(b) introducing the mixture from step (a) into at least two heat transfer coils connected in parallel and located in the bed whereby the desired operating temperature is imparted to the bed, and the liquid cryogen in the mixture vaporizes; and(c) removing the mixture of vaporized liquid cryogen and gas formed in step (b) from the coils and introducing the mixture into the bed to fluidize the bed.

Abstract: Apparatus for quick freezing of food products and the like including an insulating tank with a liquid nitrogen bath, an adjacent chamber, a conveyor system for moving product through the bath and the chamber, and an exhaust system for drawing vapor from the tank into and out of the chamber. A process for quick freezing of food products and the like wherein at least the surface of an item is frozen by immersing the item in a liquid nitrogen bath, after which the item is moved through a chamber and further cooled by vapor from the liquid bath drawn into the chamber.

Abstract: In a method of treating coated or uncoated materials made of natural or synthetic polymers in the form of continuous lengths to improve the quality of the material, the material is subjected to a series of processing steps, one of which is a cooling step in which the material is cooled by means of a cooling medium at extremely low temperature, such as a liquefied gas, for example, liquid nitrogen. Such cooling after a drying or heat-setting operation prevents creasing of the material when it is folded to form a stack. Apparatus for carrying out the method comprises a conveyor (2) for the length of material (1) and at least one blast nozzle head (3) provided with a plurality of blast nozzles (5) past which the material is conveyed, and connected to a source of cooling medium through suitable delivery means.

Abstract: A method of preparing poultry for fresh-pack handling in which the eviscerated carcasses are first thoroughly washed, then passed through a non-refrigerated water bath to pick up moisture, then tumbled to substantially equalize the moisture content of the carcasses, and to remove some of the picked-up moisture, then gravity drained to remove more of the picked-up moisture, and finally subjected to a supercold atmosphere for a time sufficient to freeze-crust it, whereby to reduce the picked-up moisture to a permissable level and thereafter to stabilize the carcasses against weepage. Routing of the carcasses and the giblets removed during evisceration may be so arranged that freeze-crusted giblets may be stuffed into carcasses before the latter are crusted, for greater ease of handling.

Abstract: An improvement in a method of preparing catalysts for the manufacture of maleic anhydride by oxidizing a saturated hydrocarbon. The catalyst is prepared by a process in which a catalyst precursor, containing tetravalent vanadium, is formed into agglomerates and calcined, the improvement being quick freezing the catalyst precursor before calcining.

Abstract: A system for heating or cooling articles conveyed in a vertical helical path is defined by an endless conveyor belt driven at its inner edge by contact with a rotating drum and a circulating heat exchange fluid propelled horizontally onto the articles by axial flow fans rotating in a vertical plane. The system features a novel arrangement employing scroll means for confining the circulating heat exchange fluid to a substantial portion of the helical path and location of fan means such that the heat exchange fluid is propelled in push-pull manner from the discharge side of one fan means to the intake or suction side of a second fan means. In the preferred embodiment directed to refrigeration of conveyed articles, more particularly foodstuffs to be frozen, the conveyor is located within an insulating housing. Further featured novelty includes location of the driving means for the rotating drum externally of the housing and directing of refrigerant, such as liquid CO.sub.

Abstract: A system (10) for chilling warm animal carcasses (30) more quickly and without substantial tissue shrinkage from dehydration includes an enclosure (12) defining a first subchamber (24) and a second subchamber (26). The carcasses (30) are conveyed into the first subchamber (24) for liquid immersion into a tank (52) of cryogenic fluid to crust-freeze the exterior carcass portions. Following immersion, the semi-chilled carcasses (30) are held in the second chamber (26) while cryogenically refrigerated, sub-freezing gas is circulated around the carcasses to complete the chilling process.

Abstract: A method and apparatus for cooling a continuously moving strip of asphaltic material includes directing the asphaltic material into a plurality of loops having lengths and widths, spraying an evaporative liquid onto the asphaltic material from spraying means positioned upstream from various ones of the lengths, and evaporating the evaporative liquid immediately downstream from each of the spraying means by causing an array of air jets to impinge on the asphaltic material substantially normally to the lengths.

Abstract: A device for cooling a gas to below its dew point by heat exchange with a low-boiling gas includes a double-walled cooling pipe with an annular space between the walls having an inlet for the low-boiling liquefied gas and a drain pipe for the evaporated gas, with at least one blow-in opening for the low-boiling liquefield gas being in the zone of the intake opening of the cooling pipe; a movable ice scraper is arranged at the intake opening and is periodically movable over the blow-in opening for the low-boiling liquefied gas.

Abstract: A chiller for edible food products including an insulated enclosure, an endless conveyor conveying the edible food products along a serpentine path through the enclosure along a plurality of vertically extending flights alternating between upward and downward movement and a horizontally extending flight above the vertical flights, means for evenly distributing a heat transfer liquid uniformly over the horizontally extending flight so that the heat transfer liquid falls over the food products moving along the horizontal flight, and deflection means below the horizontal flight between the vertical flights for deflecting the heat transfer liquid into registration with the vertically moving flights.

Abstract: A method of freezing animal carcasses comprises spraying the carcass with liquid nitrogen to produce a chilled outer layer thereby to seal the moisture within the carcass for the dual purpose of maintaining the quality of the meat and preventing the frosting or icing up of the heat exchange coils of a forced draught cooling system utilized subsequently to bring the entirety of the carcass to a desired chilled or frozen condition. Also disclosed is a freezing room including means for liberating a cryogenic liquid into the air stream from the fans of a forced draught cooling system for rapid pull-down of the room temperature.

Abstract: A system for heating or cooling articles conveyed in a vertical helical path is defined by an endless conveyor belt driven at its inner edge by contact with a rotating drum and a circulating heat exchange fluid propelled horizontally onto the articles by axial flow fans rotating in a vertical plane. The system features a novel arrangement employing scroll means for confining the circulating heat exchange fluid to a substantial portion of the helical path and location of fan means such that the heat exchange fluid is propelled in push-pull manner from the discharge side of one fan means to the intake or suction side of a second fan means. In the preferred embodiment directed to refrigeration of conveyed articles, more particularly foodstuffs to be frozen, the conveyor is located within an insulating housing. Further featured novelty includes location of the driving means for the rotating drum externally of the housing and directing of refrigerant, such as liquid CO.sub.