A process for thawing of deep-frozen foods, in particular for thawing blocks frozen fish in

摘要

1,197,954. Thawing frozen foods &c. CLARKE-BUILT (WILLIAMS) Ltd. 20 May, 1968 [23 May, 1967], No. 23978/67. Heading A2D. Frozen products are thawed by enclosing in a sealed chamber, removing substantially all the air from the chamber and then admitting steam to establish a predetermined temperature within the chamber and to condense directly on the surface of the product and thaw it. Air is subsequently readmitted and the thawed product and the condensed steam and water draining therefrom are withdrawn from the chamber. With frozen food, such as fish, the chamber is evacuated to about 2 mm. mercury and steam is then admitted until the temperature rises to 8-9‹C., as determined by a wet bulb thermometer, and at which level the temperature is maintained by automatic control of the steam supply to the chamber. A flow diagram illustrates a suitable apparatus in which steam ejectors are used to remove the air and condensate from the chamber.