GB572446A - Improvements in or relating to the dehydration of food - Google Patents

Abstract

572,446. Dehydrating food &c. BLACKALL. S. W. E. Sept. 28, 1943, No. 15943. [Class 34 (ii)] [Also in Group X] Material, e.g. food, supported on a vertical tier of perforated trays 16 in a cabinet 10 is dehydrated by subjecting it to a heated atmosphere, preferably air, which passes in a closed circuit upwardly through the cabinet in a sinuous path across the trays, and then through a conditioning chamber 29 in which it passes through a water shower or curtain to cool and wash it, and through a heater before returning to the cabinet. The curtain of water falls from a perforated channel 30 at the top of the conditioning chamber to a grating at the bottom, to condense absorbed moisture. A perforated metal plate, sheet of cotton mesh or row of metal bars 43 prevents the cooling water from being carried forward from the chamber 29. The air then passes between pivotally adjustable baffles 35 and electric heaters 36 to the fan 37 which returns it to the bottom of the cabinet. Each tray comprises a wooden frame 17 carrying a perforated metal sheet 18 with upstanding walls 19 one of which is recessed inwardly at 21 over the perforated metal sheet for the passage of gases. There are two vertical tiers of trays, which are so arranged that the recesses 21 are alternately at the sides and centre of the cabinet. At the top of the cabinet the air enters a central passage 40 through openings 41 at each side, and passes down through a rear conduit 42 to the conditioning chamber 29. Alternatively, the air returns from the top of the dehydrating chamber to the conditioning chamber through passages in the side walls of the cabinet. The air entering the cabinet may be at 130‹ to 170‹F.