Abstract: A method of treating vehicular brake pads to increase the wearability of the pads by allowing them to absorb and dissipate more energy with each use. The method involves a controlled thermal cycling process which lowers the temperature of the pads to about -300.degree. F. and holding the pads at this temperature for a predetermined time. The pads are then gradually warmed to room temperature (72.degree. F.).

Abstract: Cooling apparatus comprises a cooling chamber such as a freezing tunnel having a pipeline for introducing liquid nitrogen into it and an exhaust passage for cold nitrogen vapor. The exhaust passage extends through a rotary regenerative heat exchanger. Downstream of the heat exchanger is a fan operable to draw the exhaust gas through the heat exchanger. A second passage extends through the heat exchanger and is arranged for the flow therethrough of relatively warm air, whereby, in operation, the air is able to transfer heat to the exhaust gas in the heat exchanger.

Abstract: Food product chilling apparatus is afforded herein comprising an elongated water tank and a modular movable belt conveyer unit that carries warm food products through water for chilling. A superstructure and hoist system lifts the conveyor unit out of the water for servicing. Cooling water is recirculated and rechilled in a cooling method that controls the temperature of the efflux water from the cooling tank. The influx chilling water is distributed in a plurality of parallel flow paths incrementally chilling the product at various stations along the conveyor belt path to reduce the average cooling time for the processed products. By standardizing the efflux water temperature at the various stations at a few degrees Fahrenheit above the influx water, a thermally efficient cooling system is provided. Each of the cooling stations is provided with weir height control means to optimize the cooling rate along the length of the conveyor belt.

Abstract: An apparatus and method is provided for initially freezing a first exterior surface of a product such as a food product. The product is then supported on a perforated conveyor belt with the frozen first exterior surface in contact with the conveyor belt. The product is then further frozen and processed. Because the frozen surface of the product is hard, it does not conform to the surface contours of the belt and the unmarred visual appearance of the product is maintained. In addition, the frozen surface of the product is more easily removed from the belt after complete freezing and damage to the product is less likely to occur during removal of the belt.

Abstract: Sampling device removably mounted proximate the discharge opening in an immersion freezer to collect samples of frozen product as they exit the immersion freezer conveyor and are deposited into a second freezing or equilibrating device.

Abstract: A trap or seal system for effecting an air impervious seal for a food freezer, such as a cryogenic or mechanical freezer. The seal system includes a barrier forming a vapor-impervious partition and which has its bottom extending into a cryogenic bath. A conveyor system is used to transport articles through the cryogenic bath to a downstream cryogenic freezer. The combination of the barrier extending into the cryogenic bath forms an effective seal to prevent air infiltration into the cryogenic freezer.

Abstract: A process for treating an article of metal containing material such as tool steel so as to improve the properties such as shockability, wearability, stability and hardness of the article. In one embodiment, the process comprises immersing the article at ambient temperature into liquid cryogenic material for a time period up to or equal to a set time period equal to the minimum cross-sectional dimension in inches times ten minutes. The article is then withdrawn from contact with the liquid cryogenic material and immediately subjected to a flow of air sufficient to raise the temperature of the article to ambient temperature in a period of time equal to or less than ten minutes plus ten minutes per minimum cross-sectional dimension in inches.

Abstract: Deep-frozen cooked potatoes are prepared by cooking potatoes, slowly cooling the cooked potatoes and then deep-freezing the cooled potatoes to a storage temperature in two steps so that in the first step, the cores of the potatoes are kept at the crystallization state of water for at least 15 minutes and so that in the second step, deep-freezing is continued until the frozen storage temperature is reached.

Abstract: The present invention provides a food processing system and method for refrigerating articles of food. The food processing system includes at least two cooling stages formed by a cryogenic freezer and a hydrocooler. The cryogenic freezer receives the articles of food and transfers heat from the articles of food to the cryogen so that the articles of food are refrigerated. After the transfer of heat from the articles of food to the cryogen, the cryogen boils off to form cryogenic vapor. The hydrocooler receives the articles of food prior to the cryogenic freezer and transfers heat from the articles of food to supplied cooling water. Such heat transfer reduces the quantity of cryogen required to refrigerate the articles of food. Additionally, an eductor is connected to a pump and to vent line from the cryogenic freezer.

Abstract: A storage apparatus comprises a housing defining a plurality of chambers disposed one next to the other, the housing including partitions for separating the chambers from one another. Temperature control components are provided for controlling temperature independently in each of the chambers. Access openings are provided in the partitions between the chambers for enabling communication between each chamber and the chamber of chambers contiguous therewith. A support member movably supports a plurality of specimen-containing receptacles within the housing, while a drive is operatively connected to the support member for moving the receptacles from chamber to chamber through the access openings. An access door in the housing enables deposition and removal of a selected one of the receptacles from the housing.

Abstract: A method of freezing, storing and thawing collagen-rich tissue, such as heart valves. The method includes a freezing profile for freezing the tissue down to the temperature of liquid nitrogen with minimal tissue damage due to ice crystal formation. Heart valves cryopreserved according to the present process exhibit a high cell viability when thawed and are suitable for implanting in human patients.

Abstract: To enable centrifuging to occur at precisely determined sample temperatures, a method of centrifuge calibration which permits rapid and accurate refrigeration of the rotor containing the sample is disclosed. A rotor with sample to be centrifuged is placed within a centrifuge can. Temperature of the radiometer T.sub.ra, and temperature of the surrounding refrigerating can T.sub.c is determined at a first time, t.sub.0. Thereafter, and at a second time t.sub.1, temperature of the radiometer T.sub.ra, and the temperature of the surrounding refrigerating can T.sub.c are equilibrated. The temperature excursion between t.sub.0 and t.sub.1 for the temperatures of the radiometer T.sub.ra and the temperature of the refrigerating can T.sub.c are measured to yield respective .DELTA. T.sub.ra and .DELTA. T.sub.c. The radio of .DELTA. T.sub.ra /.DELTA. T.sub.c is taken to give a constant which comprises the view factor from the radiometer for the particular shape of rotor and the surrounding can.

Abstract: A refrigeration system that maintains the temperature of products continuously within prescribed limits, while using electrical power only during selected time periods of each day, when the cost of that power is relatively low. During that time period, the refrigeration system cools the product to a temperature significantly lower than its normal storage temperature, such that subsequently, during a time period when electrical power is relatively expensive, the compressor and fan of the refrigeration system are disabled and the inherent thermal storage capacity of the product, itself, ensures that the product temperature will not rise above a predetermined maximum temperature.

Abstract: Apparatus for treating biological specimens at low temperatures for subsequent microscopic examination comprises a container having a specimen treatment chamber disposed in a vessel adapted to contain liquid coolant. The specimen treatment chamber is adapted to receive a specimen to be treated and a specimen treatment medium. Precooling means is provided for precooling the specimen treatment medium before it is introduced to the specimen treatment chamber. The precooling means comprises a reservoir communicating with the specimen treatment chamber, and delivery means for delivering the specimen treatment medium to the reservoir. The reservoir and delivery means are arranged so that specimen treatment medium flowing through the reservoir and delivery means is cooled by the liquid coolant, and so that the specimen treatment medium can flow through the delivery means in countercurrent heat exchange with specimen treatment medium flowing from the reservoir to the specimen treatment chamber.

Abstract: Method of and apparatus for freezing food rapidly by immersing the same in the brine. According to the present invention, food is wrapped in a film which is non-permeable to water, and the resultant food is immersed in the fluidized brine of different temperatures in sequence. The food is frozen with little difference between the temperature of its outer circumferential portion and that of its core portion as the food is immersed in the fluidized brine of different temperatures in sequence. Accordingly, no cracks occur in the food while it is frozen, and no change occurs in the quality of protein in the core portion of the food.

Abstract: A method is provided for killing and preserving fish in a fresh state or a two stage procedure. In the primary or instant cooling stage, fish are killed instantly by the shock of emersion in a rapid cooling fluid. This fluid subjects the surface layer of each fish to a temperature below that at which they will be stored. In the secondary or storage stage, individual fish are either passively cooled on the inside by their low temperature surface layer, or else they are cooled inside and out by external means. An apparatus is also provided for this method and is comprised of the following: a rapid cooling hopper to deliver fish into the system, a primary rapid cooling tank to instantly kill fish, and a device connected to the primary rapid cooling tank to discharge fish to the secondary stage cold storage tank.

Abstract: Bottles 1 are disposed in an inverted position in small groups on a tray which is placed in position on a lower frame 25 of a programmed raising and lowering portal 6. Upon each lowering of the portal, the necks of the bottles are dipped into a bath of liquid nitrogen which is maintained at a constant level. The dippings, for example three in number, are separated by stages in which the necks of the bottles are maintained out of the bath. The last dipping terminates when the necks are partly frozen, and the bottles are then conveyed to a disgorging station where the mass of ice formed is expelled so as to eliminate the sediment coming from the fermentation of the champagne.

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: A process for treating a material to improve its structural characteristics comprises the steps of suspending the material closely above a cryogenic liquid for between about two hours and about four hours and, thereafter, completely immersing the material from its suspended position into the cryogenic liquid within about two seconds to about ten seconds. The rate of evaporation of the cryogenic liquid is then controlled so that the material is completely exposed to only gases within about five hours to about ten hours and, subsequently, the temperature of the material is controlled to rise from the cryogenic level to about -50.degree. F. within about eleven hours to about sixteen hours. After the material temperature reaches about -50.degree. F. within the specified time, the material is then allowed to return to ambient temperature of between about 65.degree. F. and about 70.degree. F. Thereafter, the material is heated to a temperature within the range of about 330.degree. F. to about 370.degree. F.

Abstract: A method of freezing boiled rice or a blanched leafy vegetable in a freezer having an operating temperature from -25.degree. C. to -50.degree. C. characterized in that before entering the freezer, the unfrozen product is cooled and intimately mixed with from 20% to 80% by weight based on the weight of the mixture of already frozen free-flowing boiled rice or blanched leafy vegetable.

Abstract: A cold station thermal switch at the end of a cold finger in cooperation h the detector on an inner dewar wherein the thermal switch opens at the cool down cryogenic temperature to prevent vibrations from the cooler system from being transmitted to the detector. The thermal switch has an outer bellows fitted around the end of the last stage of the cooler which extends close to but not in contact with the detector and an inner bellows having a metallic bumper on the end thereof in contact with the detector until cool down to the operating cryogenic temperature at which time contraction of the inner bellows disconnects the metallic bumper from the detector.

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: After baking bread dough goods in an oven at about 375.degree. F., their temperature is lowered to at least about 120.degree. F., and they are then cryogenically cooled to about 45.degree. F. or below in about 5 to about 15 minutes. The baked goods are then maintained at a temperature of about 37.degree. F. to about 45.degree. F. for at least about 25 minutes to effect substantial starch crystallization; after which time, slicing, bagging and freezing are carried out. Cryogenic cooling is preferably effected in a CO.sub.2 cooler, and the cooled baked goods are maintained at about 40.degree. F. for between about 25 and about 60 minutes prior to freezing by movement along an insulated conveyor which is cooled by circulation therethrough of cold CO.sub.2 vapor exhaust from the CO.sub.2 cooler.

Abstract: An improved quick-freezing process for whole blue crabs to be subsequently served whole as steamed crabs with enhanced flavor and providing extended shelf life without loss of flavor or texture. The process includes the steps of quick cooking whole blue crabs while maintaining maximum water content using a sugar-liquid bath, chilling while maintaining maximum water content using a sugar-liquid bath and quick freezing to at least -15.degree. F. without cracking, and storage at a uniform temperature of at least -15.degree. F.

Abstract: Articles of food to be frozen are delivered to an article conditioning conveyor and are maintained in a fluidized state by refrigerated air flowing upwardly therethrough. The conveyor is driven forwardly but is interrupted by at least one downward stepping movement, causing a thinning of the product bed and a rapid increase in air velocity to thus cool and separate the food articles preventing them from freezing to one another. The food articles are thereafter subjected to deep bed mass fluidization by flowing freezing air therethrough in a fluidized state.

Abstract: A device for cooling air to a temperature below its dew point and for separating condensed liquid from the cooled air to produce dry air is disclosed.

Abstract: A cooked product is coolant by interval or intermittent showering with coolant in a process which can be completely automated. The product is cooled with a cold shower for a specified period of time, after which the shower is turned off for a time sufficient for heat to be transmitted from the core of the product to its outer surface so that the surface is heated and dried. This on/off cycle of the shower is repeated until, by successive extractions of heat from the product surface, the desired internal temperature of the product is reached. In comparison with continuous showering, this method permits equivalent cooling with substantially less than half the quantity of coolant and in a shorter time, all because of more efficient use of the coolant.

Abstract: Arrangement in a freezing plant, comprising a combination of a conventional freezer and a precool unit. The arrangement is connected between the freezer and the precool unit in such a way that the amount of air in the freezing plant is maintained substantially constant without any reaction with the ambient atmosphere.

Abstract: A method of chilling articles and materials, especially for the embrittlement thereof prior to comminution, wherein a cooling-gas stream is produced from a deep-cooled liquefied gas and the cooling-gas stream is passed into direct contact with the materials to chill the same. The invention comprises evaporating the liquefied gas to produce a first cold gas stream into indirect heat exchange with an evaporating fluid (of an independent refrigerating cycle) to cool the further gas stream and generate therefrom a second cold gas stream, and mixing the first and second cold gas streams to form a mixture which is brought into direct contact with the materials as part of the cooling thereof.

Abstract: Preservation of biological materials is accomplished by apparatus and a process with and by which the material is cooled at a substantially linear rate to approximately freezing temperature, changed from the liquid to the solid phase at relatively constant temperature, and cooled at a substantially linear rate to an end temperature. The environment surrounding the material is rapidly chilled when the material reaches freezing temperature or a temperature minimally warmer than freezing temperature in the liquid phase to initiate phase change with minimal risk of super cooling the material, and is then warmed to freezing temperature or a temperature minimally cooler than freezing temperature to minimize temperature drop in the material upon completion of phase change. The apparatus contemplates, among other things, preselection of cooling rates, duration of phase change, and the end temperature.

Abstract: The invention is concerned with a method of preserving extracted teeth with attached live root membrane. After treating the teeth in order to eliminate bacteria and fungi in a nutrient solution to preserve the viability of the root membrane cells the teeth are subjected to a freezing process in two stages and in the presence of a similar nutrient fluid, the temperature being lowered slowly in the first stage to a value between -20.degree. and -50.degree.C and rapidly in the second stage to a value below -50.degree.C, preferably below -150.degree.C.

Abstract: An I.Q.F. system for deep freezing of food articles and the like employing a deep bed fluidization second stage freezer and an article conditioning first or input stage wherein the initially moist unrefrigerated articles massed in a relatively thin deposit are subjected to through-flow of subfreezing gas, preferably under fluidization conditions, for a predetermined period which removes substantially all of the sensible heat above freezing without removing the latent heat from the articles, whereupon, articles thus in condition compatible for deep bed fluidization freezing in the second stage are delivered from the first to the second stage.

Abstract: An apparatus for cooling goods by contacting the goods with low temperature gas while transferring intermittently the goods. The low temperature gas is circulated forcedly in a section while being flowed in a direction reverse to the direction of transferring goods.

Abstract: A carefully controlled, multistage freezing and thawing process for the preservation of animal semen, blood, and other biological materials. A variety of diluting substances can be utilized to effectively modify the cell membrane's permeability to water and to initiate and/or alter the process of crystallization to minimize undesirable physio-chemical effects.A sample of semen is diluted with a suitable cryoprotective agent to achieve a final pH of 6.0 to 6.3 at +5.degree.C. The sample is collected at body temperature and cooled slowly to +5.degree.C, held at this temperature for 30 minutes or longer, followed by a rapid decrease in temperature to a nominal -4.degree.C, or a temperature slightly below the freezing point of the diluent. The sample is held at this temperature for a period of 1 to 8 minutes to allow adjustment and stabilization of the temperature induced changes in pH and associated alterations in membrane permeability and osmotic pressure.

Abstract: .Iadd.A cryogenic freezer for freezing products comprising an elongated horizontal tunnel, a conveyor extending therethrough, a liquid cryogenic spray at the outlet end of the conveyor, a plurality of substantially closed gas recirculating flow paths in series relationship along the length of the tunnel and individual fans in each recirculating flow path for causing gas contact with product being conveyed through the tunnel. .Iaddend.