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AssigneeAir Products and Chemicals, Inc.
InventorsJeremy P. Miller, Charles M. Monroe, Mark S. Williams, Miles P. Drake
Estimating the term…
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.
A refrigeration apparatus including a buffer vessel, a compressor for compressing gaseous refrigerant from said buffer vessel, a condenser for at least partially condensing refrigerant from said compressor, an expansion device for expanding fluid from said condenser, a line for carrying expanded fluid to said buffer vessel, an evaporator arranged to receive liquid refrigerant from said buffer vessel, and a pipe for returning at least part of the fluid from said evaporator to said buffer vessel, characterized in that said refrigeration apparatus further comprises a heat exchanger arranged to condense gaseous refrigerant from at least one of said evaporator and said buffer vessel and connected or connectable to a source of liquid nitrogen.
Dependencies are inferred from the claim text.