Air Products and Chemicals, Inc.

Other

American Metalcasting Services Int'l Inc.

Jeremy P Miller

Mark Sherman Williams

Charles M Monroe

Jean-Philippe Trembley

Colin D Smith

Rodney John Allam

Joseph Perry Cohen

Edward F Kiczek

Anthony Knut Topham

Miles P Drake

Michael Robert Himes

John V Summers

Stuart Bruce Williams

William Lee Tordoff

Sean T Jones

A cryogenic tunnel freezer () having modular design and construction including a lower section () that can be raised and lowered relative to an upper section (), the upper and lower sections () defining a tunnel () when the lower section () is in a closed (raised) position. Product is moved through the tunnel () via a belt () formed of arrays of plastic modules () that are reinforced by metal chains () and rods (). The lower run () of the belt () rides on the floor () of the lower section () and the upper run () rides on the lower run () when the belt () is operated. The flow of cryogenic fluid through the tunnel () is aided by vaporization of a cryogenic fluid and baffles (), but no air-moving devices located within the tunnel ().

Cryogenic tunnel freezer

A method for determining the flow rate of a fluid, having a liquid fraction and a gas fraction, having the steps of: measuring the pressure and temperature of the fluid at a flow control device through which said cyrogenic fluid passes; inputting the measured pressure and Cinto an algorithm; and performing a single or multi-step iteration to determine a fluid mass flow rate of the fluid through the flow control device using the algorithm that relates the mass flow rate of the fluid to the C, and mass densities of the liquid fraction and the gas fraction of the fluid which are a function of the measured pressure, and temperature. A system is also provided.

Flow monitoring using flow control device

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.

Method and apparatus for freezing products

A method of freezing a product, which method comprises the steps of vaporizing a cryogenic liquid and warming the vapor thus formed in indirect heat exchange with a product to be frozen, work expanding the warmed vapor, and using the work expanded vapor thus obtained to refrigerate the or another product.

A method of cooling an aqueous liquid, which method comprises the steps of:

Method and apparatus for cooling an aqueous liquid

Method and apparatus for reclaiming sand from a foundry sand containing, inter alia, a clay binder by cooling the foundry sand to a temperature at or below -40.degree. C. (-40.degree. F.) followed by separation of the sand from the binder while the sand is maintained at a temperature at or below 0.degree. C. (32.degree. F.). Foundry sands with clay binders have a water content to 1% to 15% by weight prior to being cooled.

Method for cold reclamation of foundry sand containing clay

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.

Method and apparatus for molding a food product

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.

Method and apparatus for freezing

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.

Tunnel freezer

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.

Combination immersion/impingement tunnel freezer

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.

Refrigeration system

A method of freezing aqueous liquids which method comprises the steps of:

Method and apparatus for freezing aqueous liquid

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.

Refrigeration apparatus and method of refrigeration

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). The dispenser has particular utility in high speed canning and bottling lines.

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Mortimer, United Kingdom

Jeremy P Miller