Nitrogen spray refrigeration system for perishables

Claim 1

Apparatus for refrigerating perishable products comprising in combination: a. a storage chamber for said perishable products having thermal insulation sufficient to limit heat inlead rate below 0.10 Btu/hr-*F-ft2 and cross-sectional area between 40 and 100 ft2; b. a thermally insulated container associated with the storage chamber for holding pressurized nitrogen-rich liquid; c. spray conduit means positioned within the upper portion of said storage chamber and extending substantially the entire length thereof with openings of equivalent diameter less than 0.07 inch spaced along the length for discharging a multiplicity of discrete cold fluid streams into the storage chamber for refrigerating same, said openings having total area of between 0.002 and 0.009 in2 per 10 ft average length of chamber; d. fluid discharge conduit means communicating at one end with the liquid container and at the other end with said spray conduit; e. fluid flow control means comprising a temperature sensing element positioned within said storage chamber, and a control valve operably interposed in said fluid discharge conduit means being connected to said temperature sensing element to be responsive to the storage chamber gas temperature as sensed by such element.