Abstract: Pieces of aramid cloth impregnated with a blend of phenolic and polyvinyl butyral resins are cryogenically chilled to the point of embrittlement in a liquid nitrogen bath and then fed to a rotary impact mill to comminute the pieces into a fibrous material suitable for use in brake linings or other friction applications. The rotary impact mill is chilled by cold gaseous nitrogen from the liquid nitrogen bath, the flow of which is controlled in response to a thermocouple disposed near the mill exit.

Abstract: Used products, which would otherwise be disposed of as waste, are subjected to low temperature lowering the temperature of the product to approximately the temperature of crystallization of the components thereof. The product at this lowered temperature is then crushed sufficiently to cause the components thereof to release sufficiently to be subsequently separated according to material. The separation steps can include subjecting the crushed material to magnetic or electrostatic fields, air flows caused by either pressurized air or vacuums, and mechanical separation with vibratory screens and rakes. The materials of the original product are sufficiently separated to enable them to be recycled into usable product. The particular example cited relates to vehicle tires with the materials recovered including rubber, fiber and metal bands.

Abstract: Animal or plant derived materials are prepared for extraction of desired substances therefrom by grinding said materials at or below their Brittleness Temperature. This treatment allows fracture of the materials into small particles with high surface area to volume, as well as high volume to mass ratios, and disrupts membranes of tissues, organs, cells or organelles which would otherwise prevent or limit separation of desired biomolecules.

Abstract: Absorbent retentive pulp is described which is capable of retaining good absorbency even after having been highly compressed. The pulp is produced by subjecting a microfibrillated pulp slurry to pore generation with pore generating particles and to cross-linking with a cross-linking agent.

Abstract: A process for increasing tree unit shelling efficiency includes a means of temporarily hardening the kernels of unshelled nuts to increase the efficiency of conventional nut hulling and/or shelling means. Quick freezing is used to sufficiently lower the temperature of the kernels of unshelled nuts to freeze the liquid matter contained in the kernels with minimal ice crystal formation. A higher percentage of nut kernels remain intact during hulling and/or shelling. The hulls and/or shells of the nuts remain substantially unaffected by quick freezing.

Abstract: Crushed particles of coal, ores or industrial minerals or rocks are comminuted by feeding them through a feeder (14) into a cyclic stream (19, 22, 38, 39, 41) of cryogenic process fluid such as liquid carbon dioxide and conducting the process stream with the entrained mineral particles to a comminuter (17) and through a zone therein of mechanically generated high frequency vibratory energy, preferably ultrasonic. The comminuter (17) may be multistage with means for re-cycling oversize mineral particles and, after leaving the comminuter (17) the process stream (38) is conveyed to a separator (18) for extracting the comminuted particles and re-cycling the cryogenic fluid to the feeder (14). The low temperature of the process stream is maintained by refrigerating means (16) and losses of the fluid are made up by supplementary fluid fed to the stream.

Abstract: Cryogenic process and apparatus for removing adherent coatings or linings from metallic substrates, especially the interiors of metal vessels or pipes. In one embodiment, a metal vessel having a polymeric interior lining is pressurized to about 900 psi, and the lining is contacted with a cryogenic liquid, preferably carbon dioxide, while this pressure is maintained. The pressure is high enough so that the cryogenic liquid does not boil. The lining is then subjected to shock by ultrasound, for example. This causes the lining to break up into small particles and fall off the metal substrate. These particles, suspended in the cryogenic liquid, are removed from the pressure vessel and separated from the cryogenic liquid, which can be reused. In another embodiment, the cryogenic liquid is injected into a pipe having an adherent mineral deposit while maintaining a pressure of about 700 psi. A stream of cryogenic liquid containing suspended mineral particles is removed from the pipe.

Abstract: The invention provides a method and apparatus for preparing frozen free-flowing particles of food product. Particles of solid food are supplied, or viscous food material is extruded, or liquid or semi-liquid food material is pumped through apertures, to a freezing stage. In the freezing stage, cryogenic substance is used to freeze the food material to a temperature at which the material is frangible. The frangible food material passes to a fracturing stage such as a fracturing mill, which produces frozen food particles of a size small enough to pass through discharge apertures of the fracturing stage. The discharged particles are screened to remove undersized particles which are recycled, the remaining frozen particles being generally within a defined size range and constituting the final product.

Abstract: Cold-embrittled parts are surface treated by an abrasive jet through the use of an arrangement which includes as a centrifuge wheel. The centrifuge wheel is self-priming and is connected to a granulate collecting tank via a suction pipe with a spray nozzle for low boiling liquefied gas being arranged in the inlet zone of the suction pipe. The resulting abrasive jet pattern is of the same shape and size as the treatment surface.

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: A process for treating pollen which comprises freezing said pollen grains by immersing in low temperature liquefied gas so as to make them low temperature brittle, and pulverizing said pollen grains while they are still in the low temperature brittle state by means of a pulverizer of impact type, or further adding aqueous ethanol solution as the solvent to the pollen grains treated in the above manner, and after extracting the effective ingredients of said pollen grains at room to elevated temperatures with stirring, removing the residue and then concentrating the clear extract thus obtained under vacuum.

Abstract: The removal of paint from a support device for a product in a paint finishing operation is improved by using a support device with a critical surface tension such that paint adheres to the surface, yet readily fractures and debonds when treated with a cryogenic liquid. The paint is then removed by contacting the cryogenically treated support device with a non-metallic, non-silica base solid, gas or liquid with sufficient force to effectively remove the paint.

Abstract: A tissue pulverizer for pulverizing specimens of living tissues for facilitating chemical testing and the like. The pulverizer has a base, a guide member for emptying into a receiving tube and an elongated pestle member. The parts are cooled with liquid nitrogen and the specimen inserted, covered with the cooled pestle and frozen. The pestle member is then struck with a hammer to pulverize the frozen sample.

Abstract: A cryogenic liquid is used to directly or indirectly cool solid or liquid contaminants adhering to apparatus surfaces to effect a change in the physical characteristics of the contaminants and thereby render them more susceptible to removal operations.

Abstract: The invention relates to cryogenically cooling and impacting thermoplastic coated fabric to liberate the thermoplastic from the fabric and screening the resulting thermoplastic fabric mixture in a multi-deck vibratory screener into a coarse fabric segment, a thermoplastic fines segment and a third segment. The third segment is separated into a fabric fines segment and a coarse thermoplastic segment in, for example, an air classifier. The recovered thermoplastic coarse and fines segments can be reused in all applications for regrind thermoplastic material.

Abstract: Absorbent retentive pulp, produced by mechanically treating a dispersion of cellulose fiber to the disintegrated and outer secondary walls to microfibrillar form. The beaten dispersion is then freeze dried.

Abstract: In an insulated mixing and cooling chamber having a feed auger to deliver cooled particles to a grinder and an intromitter auger rotatable around the feed auger to mix the particles within the chamber, independent variable speed, reversible motors operate the intromitter and feed augers, whereby the relative rotation of the augers may be precisely adjusted even while the mixing apparatus and associated grinding apparatus are operating. Electronic and or pneumatic control of cryogenic liquid inflow, as well as electronic control of the auger drive motors, may be used to optimize cooling and mixing conditions.

Abstract: An apparatus for intraoperative diagnosis is described which comprises a refrigerating device adapted to sprinkle a cryogenic liquid on the surface of a slide whereby the surface of the slide is cooled to at least -4.degree. C. up to -8.degree. C., at least one cooling fan which increases the evaporation of the cryogenic liquid and permits to achieve the necessary hypothermia on the slide; an automatic appositor which permits to exert a measurable and graduated pressure onto the section of the organ which has been interposed between the appositor and the slide at the time in which the section has reached a predetermined temperature. The appositor is provided with means for varying automatically the pressure during the advance of the slide. The refrigerating device comprises a cylinder containing a cryogenic liquid.

Abstract: A cryogenic liquid is used to directly or indirectly cool solid or liquid contaminants adhering to apparatus surfaces to effect a change in the physical characteristics of the contaminants and thereby render them more susceptible to removal operations.

Abstract: Metallized plastic such as chrome plated plastic is processed to separate metal from plastic and especially to recover reusable, essentially metal-free plastic. Metallized plastic is comminuted, as necessary, to suitably sized pieces which then are exposed to cryogenic temperature and impacted in a rotary mill to form a mixture of plastic and metal particles. Subsequently most of the metal particles are removed from the mixture by effecting particle size and magnetic separation steps. Oversized particles can be recycled for further processing. The recovered plastic is then extruded, under conditions which render it molten, through one or more screens.

Abstract: A barrier sheet suitable for use in the manufacture of cured rubber products, such as tires, belts or the like, is produced by a method which includes the steps of coating elongated reinforcement cords with uncured rubber, cutting the coated reinforcement cords to form short lengths, lubricating the short lengths to prevent balling and sheeting-out the fine particles to form a sheet of green barrier material. The barrier sheet formed by this method may be laid in to a tire during a tire building operation to form a tire reinforcement.

Abstract: This invention relates to a method and apparatus for grinding with two toothed plates operating face to face, one of which plates is fixed and the other of which is rotated by a shaft, with an axial supply of material to be ground and peripheral evacuation of the ground products. Chambers are provided for circulating of cooling water in contact both with the fixed plate and with the rotatable plate. At an intermediate radial point of the plates, a liquid nitrogen injector which enables reduction of the temperature of the product during treatment and making the grinding zone inert is fitted. The invention is applied to the grinding of rubber.

Abstract: In a process for the wet combustion of solid, combustible, radioactive wastes by reaction with concentrated sulfuric and nitric acids or NO.sub.x at elevated temperatures, the improvement wherein the waste, prior to the reaction, is subjected to a preliminary comminution to a particle size less than or equal to 20 mm, and then to a primary comminution, at a temperature less than about 123.degree. K, to a particle size less than or equal to 1 mm.

Abstract: Uncured rubber scrap may be segregated from metal and fiber contaminants by the method of first embrittling the scrap by immersion in a liquid cryogen, then impacting the embrittled rubber and magnetically removing metal, and then milling the remainder. Gas flotation is used during milling so that particles of rubber and fiber are selectively removed from the mill and subsequently classified by size, whereby most of the fibrous component is segregated from a remainder. The remainder is then worked so as to increase the surface area of residual fiber prior to further segregation of fiber from rubber by gas flotation. The combined milling and flotation procedure may also be used for separating components of other mixtures. Apparatus for embrittling and milling is described.

Abstract: The production rate of a conventional cryogenic grinding system incorporating an impact mill may be increased by (a) providing means to allow at least 70% of the embrittled material entering the mill to leave the mill before it passes the inlet; and (b) providing means to restrict the flow of the cold gas through the impact mill.The product leaving the impact mill is screened and any oversize is preferably recycled to the impact mill.

Abstract: Chrome plated plastic scrap is chopped into small pieces and then, while subjected to sub-zero temperatures, is centrifugally impacted thereby producing a mixture of particles of chrome and plastic. Most of the chrome particles are removed by subjecting the mixture to a magnetic field. The remaining, mostly plastic particles are classified to obtain usable, predominantly plastic particles within a predetermined size range, those particles exceeding this range being, if desired, recycled for subjection to said centrifugal impacting step. The usable particles are thus reclaimed for reuse, after repelletizing, in extrusion or molding techniques.

Abstract: A processing plant and method for processing scrap tires and similar materials containing a mixture of technical rubber, scrap metal and tire cord in which the plant is essentially vehicular and thus eliminates the necessity of hauling accumulated tires long distances with the accompanying costs; and the plant includes means for directing mixed tire sizes to a cyrogenic section where the technical rubber is reduced to a sufficient temperature making it brittle so that initial separation of reusable technical rubber is accomplished; the plant being operated essentially on the reusable by-products of pyrolytic reduction of the tires so that hydrocarbons and heated gas are utilized and additional commercial by-products such as commercial soots, metal and tire beads are obtained.

Abstract: Metal particles which are ductile at ambient temperature can be comminuted by being passed through a first impact mill at ambient temperature to increase their length to thickness ratio, embrittled, and then comminuted in a second impact mill.

Abstract: A control system for optimizing the flow of a cryogenic refrigerant into the precooler and mill of a cryopulverizing system including means responsive to a change in the discharge temperature in the mill for introducing refrigerant into the mill in direct proportion to such temperature change and means responsive to the change in discharge temperature in the mill for introducing refrigerant into the precooler at a linear rate proportional to the product of the material feed rate and the change in discharge temperature and inversely proportional to the residence time of the feed material in the precooler.

Abstract: Methods are disclosed for embrittling scrap metal for comminution and for subsequent or simultaneous treatment of the comminuted metal powder to improve sintering kinetics and prevent oxidation of alloying ingredients. A first embrittling method impacts the scrap metal at a temperature below its ductile-brittle transition temperature to cryogenically provide scrap metal powder. The scrap metal is subjected to two impacting operations (such as by use of a ball milling machine), the first operation being carried out simultaneously with the cryogenic medium and the second impacting operation is carried out at ambient temperature conditions utilizing milling elements which impart cold work to at least a portion of the cryogenic powder. An anti-oxidation agent, such as copper or iron, is mechanically transferred to substantially each particle of said cryogenic powder during the second operation to form a continuous copper or iron envelope thereabout.

Abstract: Method of making fibers suitable for making a hair brush includes a matrix or pad made of a flexible material and a plurality of relatively rigid, single natural-type bristles having their lower ends anchored by flexible, sleevelike members projecting upward from the matrix. Also disclosed is a method of forming the bristles which includes comminuting natural bristles at a low temperature and then forming a thick slurry of the comminuted bristles and a binder, which is then molded and cured to form bristles having improved characteristics.

Abstract: Low temperature embrittlement of materials which otherwise cannot be readily comminuted is carried out by treating the materials, g.g. scraps of synthetic resin containing components which might otherwise be released into the atmosphere, with a circulated cooling gas to cause the embrittlement of the materials. The latter are then conveyed through a mill, e.g. a pin-type attrition mill, in a carrier gas and are comminuted therein. The cooling gas is passed continuously around a closed circulation path so that any released components remain trapped in the circulated gas which, in turn, is cooled to a sufficiently low temperature by a separately displaced cooling fluid passed in indirect heat exchanging relationship with the cooling gas stream along the closed path of the latter.

Abstract: The present invention relates to the embrittlement of the integuments of small seeds wherein the seeds are cooled by thermal shock in a fluidized bed; cooling is provided by direct injection of a cryogenic fluid flash evaporated in the fluidized bed, forming the fluidization gas in the gaseous state, and recovery of cold by countercurrent circulation of the seeds. The process applies to small oleaginous seeds to facilitate their decortication, and to treatment of impermeable leguminous seeds to favor their eventual germination.

Abstract: The invention relates to a method of producing sand castings in which a set of castings incorporating the casting runners and risers is formed.The castings, which are cast in pairs to form compact members, are placed in baskets and are subjected to refrigeration firstly in a precooling zone and then in a dipping zone in a liquid nitrogen tunnel. After this the compact members are placed on a breaking-up table where they are subjected to mechanical shocks to enable the castings to be separated from their casting risers and runners.Applicable exclusively to "as cast" ductile cast iron.

Abstract: A plant for the cryogenic comminuting of materials which are resilient, th or difficult to comminute at room temperature, in particular rubber and plastic material, wherein the comminuting means, the charging hopper and the feeding means for the material to be comminuted are all contained within one and the same insulated enclosure, said enclosure being in communication with the outside only over calibrated adjustable openings defining a given outflow of gas, a cryogenic liquid is introduced in the comminuting means in a quantity that is variable according to the minimum optimal temperature required in the mill for any specific comminuting operation.

Abstract: A process for treating metal scrap includes cooling the scrap until it is brittle by contacting it with a first cooling agent which is gaseous and then fragmenting the scrap, said first cooling agent being cooled by being passed through a heat exchanger to which a second cooling agent is fed partly in the liquid phase and partly in the gaseous phase and from which the second cooling agent emerges in the gaseous phase, said second cooling agent being supplied to the heat exchanger partly from a liquid storage facility and partly directly from a refrigeration plant, the refrigeration plant being used in conjunction with a liquifier to supply the storage facility with liquid second cooling agent.

Abstract: Scrap tires containing magnetic components and non-magnetic rubber and cord components are cooled in a cryogenic freezer to the embrittlement temperature, comminuted in a comminution device and passed through a series of screening and density classification operations followed by magnetic material separation and further cryogenic size reduction to produce a product rubber crumb having a particle size of about 1/20 inch or less.

Abstract: A method of comminuting fresh algae which consists in carrying out a comminuting operation on said algae at a temperature lower than -20.degree.C. Preferably this temperature lies between the range -30.degree. to -100.degree. C. In carrying out the method it is advantageous for the fresh algae to be frozen at a temperature of less than -20.degree. C before being comminuted. In particular, after being broken down, the algae are comminuted by crushing into the form of a wet paste mix, the mean size of the particles in which is less than 10 micrometers.The invention also relates to apparatus for carrying out the comminuting operation which comprises a comminuting assembly and cooling means associated therewith to hold the operated temperature within said assembly at a level of -20.degree.C by means of a cooling agent. The invention furthermore extends to the algae product whenever produced by the method and apparatus aforementioned.

Abstract: A method and apparatus for separating plastic liners from metal closures is disclosed which includes a liquid nitrogen precooler for chilling closures with liners therein, a hammermill for impacting the chilled closures to liberate the liners from the closures, a tumble barrel for separating large pieces of closures from the plastic liners and the small pieces of closures, and a high-tension electrical separator for separating the small pieces of closures from the plastic liners.

Abstract: A method of converting scrap metal to a powder suitable for making sinterable shapes is disclosed. Scrap metal equivalent to machine turnings, is subjected to a two-cycle process which graduates the conversion of turnings to powder. The scrap metal, in the first cycle, is cooled to a temperature below the ductile-brittle transition point for said metal and fragmented by impact to a particle size of -1/4 inch. In the second cycle, the fragmented pieces are again cooled to below the ductile-brittle transition point for said metal and fragmented by impact to a particle size of -1/4 inch. In the second cycle, the fragmented pieces are again cooled to below the ductile-brittle transition temperature and comminuted to a fine powder of -30 mesh. During each cycle, a cryogenic cooling medium is injected into the metal collection both at the entrance to fragmenting or comminuting apparatus as well as into a circulating mass of the metal within the apparatus.

Abstract: A process for producing powdered metal which comprises taking metal swarf, removing oil and grease from the swarf, cooling the swarf to a temperature below -20.degree. C and milling the cooled swarf to form powder.

Abstract: Automobile tires and analogous articles of rubber or synthetic plastic material are frozen to make them brittle, and thereupon are fragmented in order to separate their rubber or synthetic plastic material from embedded reinforcements of textile or analogous fabrics. The fragmenting is carried out by dropping the articles into an impact mill in which a rotor equipped with striking elements turns about a horizontal axis, so that the articles are hit by the striking elements of the rotor and flung in circumferential direction of movement of the rotor against impact plates from which they drop back onto the rotor, whereby the articles are fragmented by the repeated hits and impacting. An apparatus for carrying out the method is also disclosed.

Abstract: Method and apparatus for separating metallic conductor wire from its insulation for reclamation of the metal and secondarily the insulation material. Random-size, non-uniform masses and pieces of the insulated wire are conveyed to an entrance end of a shaftless rotatable drum having helically deployed baffles along the inner surface thereof. The masses and pieces introduced to the drum initially and continuously are exposed therein to cryogenic coolant to freeze the same and render them brittle. The baffles continuously turn the frozen masses and pieces to ensure that all surfaces and areas thereof are exposed to the coolant for thorough freezing. Simultaneously, the action of the baffles and drum move the masses and pieces from the entrance end to an exit end of the drum. The super-cooled brittle masses and pieces are delivered from the exit end to a grinding apparatus where the same are reduced to particles of metal and insulation material.