Abstract: On-the-bone tenderization of a dressed freshly slaughtered unboned poultry bird is accelerated by rapidly cooling at least the breast meat of said bird by exposure to a cooling temperature of at most −10° C. to provide a frozen crust on the breast and a substantial temperature gradient through the breast meat and reducing the rate at which the breast is cooled to reduce the temperature gradient whilst maintaining the surface temperature of the breast meat below −2° C. for sufficient time to freeze only a portion of the water content of the breast meat and thereby tenderize the meat. The meat of the tenderized bird is preferably warmed towards an equilibration temperature of from 0° C. to 5° C. It is understood that reduction of maturation time occurs because a portion of the water in the meat freezes thereby concentrating the salts and other solutes in the remaining liquid water.

Abstract: A tunnel freezer having a metal belt for carrying product therethrough, wherein the weight of said belt is from 1 kg per square meter of surface area to 6 kg per square meter of surface area.

Abstract: A tunnel freezer having a metal belt for carrying product therethrough, wherein the weight of said belt is from 1 kg per square meter of surface area to 6 kg per square meter of surface area.

Abstract: The present invention relates to a novel composite adhesive used to adhere coating materials onto a substrate wherein the substrate material and the coating material have significantly different expansion properties, e.g., thermoplastic coating materials onto cellulose based substrate materials. The composite adhesive comprises both a rigid adhesive such as an epoxy or acrylic and a laminating adhesive such as a rubber based contact cement. In a preferred embodiment of the invention, the composite adhesive is used in preparing composite articles such as counters, sinks, furniture, profile edging, chemical resistant lab tops, showers, etc. In another preferred embodiment according to the invention, the rigid adhesive is applied over a narrow portion of the coating material, substrate, or both, preferably the exterior region of said material, and the laminating adhesive is applied over the remainder of the surface area to be adhered.

Abstract: In a method of forming a frozen food product, the temperature of a fluid food product is lowered so that the product is plastic. A mould is pressed against the food product to cause at least a portion of the product to take up the shape of the mould. The mould is at a sufficiently low temperature when it is pressed against the product such that the product retains its moulded shape and such that the product is readily releasable from the mould. This allows frozen confectionery products such as ice cream to be successfully moulded.

Abstract: A tunnel freezer is cooled by selectively supplying liquid nitrogen to banks of spray nozzles. The banks are switched on and off as required so that at any given time the pressure upstream of each operational spray nozzle will be substantially constant at a level which closely approximates the maximum heat transfer coefficient associated with the spray nozzle or the maximum effectiveness of the spray nozzle or a balance therebetween. The invention is in contrast to the prior art where the flow of liquid nitrogen to the spray nozzles is continuously varied in response to the thermal load.

Abstract: The present invention relates to a novel composite adhesive used to adhere coating materials onto a substrate wherein the substrate material and the coating material have significantly different expansion properties, e.g., thermoplastic coating materials onto cellulose based substrate materials. The composite adhesive comprises both a rigid adhesive such as an epoxy or acrylic and a laminating adhesive such as a rubber based contact cement. In a preferred embodiment of the invention, a spline material is also rigidly adhered to the coating material so as to reinforce the bond between substrate and coating, especially where two pieces of coating material are attached at a seam. In another preferred embodiment the composite adhesive and/or spline material is used in preparing composite articles such as counters, sinks, furniture, profile edging, chemical resistant lab tops, showers, etc.

Abstract: A turbulence inducing fan blows cold gaseous nitrogen through ducts disposed to either side of a conveyor carrying product to be frozen through a freezing tunnel. The cold gaseous nitrogen is deflected downwardly onto product on the conveyor by a baffle having, in cross section, the form of a cusp. The cold gaseous nitrogen forms two counter-rotating vortex. The cold gaseous nitrogen travels across the product and then passes into an intake cowl primarily via inlets disposed adjacent both edges of the conveyor. The intake cowl collects the cold gaseous nitrogen which is sucked into the intake of the turbulence inducing fan. This arrangement provides excellent heat transfer to the product being frozen.

Abstract: The present invention is a combination immersion/impingement tunnel freezer. A solid conveyor belt moves the items to be frozen through an initial immersion section wherein the conveyor belt is immersed in a bath of liquid refrigerant. Subsequently, the conveyor belt moves the items to be frozen through an impingement section wherein the evaporated refrigerant from the immersion section is directed toward the solid conveyor belt at a high velocity and at an angle substantially perpendicular to the longitudinal axis of the tunnel.

Abstract: A refrigeration system using air as the refrigerant comprises a compressor which compresses air to 84 bar g. The compressed air is cooled first by cooling water and then by returning air in a plate-fin heat exchanger before being expanded to 59 bar g in an expander. The expanded air at -61.degree. C. is passed through indirect cooling coils in a cold store which it leaves at -45.degree. C. This air is then passed through the plate-fin heat exchanger before being recycled to the compressor. The refrigeration delivered is about 1.05 kw refrigeration/kw power input.

Abstract: A method of freezing aqueous liquids which method comprises the steps of:a) introducing the aqueous liquid into a mould;b) allowing at least the aqueous liquid in contact with said mould to freeze; andc) releasing said frozen liquid from said mould; wherein said method further comprises the step of:d) pre-cooling said mould to a temperature such that the frozen aqueous liquid can be readily released from said mould as a unitary structure.

Abstract: A method of freezing aqueous liquids which method comprises the steps of:a) introducing the aqueous liquid into a mould;b) allowing at least the aqueous liquid in contact with said mould to freeze; andc) releasing said frozen liquid from said mould; wherein said method further comprises the step of:d) pre-cooling said mould to a temperature such that the frozen aqueous liquid can be readily released from said mould as a unitary structure.

Abstract: Supplementary cooling for a mechanical refrigeration plant using ammonia as a refrigerant is provided by placing a tube in the vapor space of a buffer vessel and introducing liquid nitrogen into the tube. Although ammonia solidifies at -78.degree. C. and liquid nitrogen enters the tube at -196.degree. C. no ammonia solidifies on the tube even after extended operation. The present invention also provides a method of refrigeration which comprises introducing liquid nitrogen into the heat exchanger of a refrigeration apparatus in accordance with the invention and condensing refrigerant therewith. Preferably, the refrigerant is selected from the group consisting of ammonia and fluorocarbon R22.

Abstract: A dispenser for cryogenic liquid comprising a vacuum insulated vessel (2) which is provided with a dispenser tube (10). The dispenser tube (10) is heated in use by an electric heater (11). Sufficient heat is supplied to achieve film boiling on the inner surface of the dispenser tube (10). Flow of cryogenic liquid from the vacuum insulated vessel (2) into the dispenser tube (10) is controlled by a tapered valve member (14) which is biased downwardly by a spring (15) and which is connected to a permanent magnet (16) disposed in a coil (17). The tapered valve member (14) can be driven upwardly or downwardly according to the sense in which a direct current is applied to the coil (17). A gas relief tube (18) is provided to vent gas from the dispenser tube (10) intermediate the tapered valve member (14) and the outlet of the dispenser tube (10). The gas relief tube (18) conveys gas to the space above the cryogenic liquid, for example liquid nitrogen, in the vacuum insulated vessel (2).

Abstract: A freezer (1) which comprises a drum (2) is characterized in that a cylinder (12) is disposed in said drum (2), and a fan (14) is provided for circulating cryogen through the space (20) between the outer surface of the cylinder (12) and the inner surface of the drum (2). The outer surface of the drum (2) is provided with a plurality of grooves (4) of parabolic cross-section. In use, droplets (23) of liquid egg are dropped on to the grooves (4) where they freeze individually. The frozen particles fall away from the drum as they approach the lowermost point of travel of the drum (2) and form an attractive granular product.

Abstract: A tunnel freezer comprises an elongate tunnel which is inclined to the horizontal and which can be rotated about its longitudinal axis. The inside of the tunnel is provided with a weir which retains a pool of liquid nitorgen between the weir and the upper end of the tunnel. Particles to be frozen are introduced into the tunnel on a conveyor and drop into the pool where they freeze substantially without aggregation. Rotation of the tunnel carries the particles out of the liquid nitrogen and through the remainder of the tunnel to the outlet end of the tunnel. The frozen particles and the nitrogen vapour from the tunnel pass through a common outlet which is provided with a pivoting plate which restricts the flow through the common outlet so that the tunnel operates at or slightly above atmospheric pressure thereby inhibiting ingress of moist air into the tunnel. Movement of particles through the tunnel is facilitated by lifting bars which form part of a liner which can be readily removed and replaced as desired.

Abstract: A freezer (1) which comprises a drum (2) is characterized in that a cylinder (12) is disposed in said drum (2), and a fan (14) is provided for circulating cryogen through the space (20) between the outer surface of the cylinder (12) and the inner surface of the drum (2). The outer surface of the drum (2) is provided with a plurality of grooves (4) of parabolic cross-section. In use, droplets (23) of liquid egg are dropped on to the grooves (4) where they freeze individually. The frozen particles fall away from the drum as they approach the lowermost point of travel of the drum (2) and form an attractive granular product.