GB647253A - Improvements in or relating to the dehydration of foodstuffs - Google Patents

Abstract

647,253. Drying chambers. DAVID, V. M. July 1, 1947, No. 17277. [Class 34(ii)] [Also in Group VI] Food is placed in a retort 14 which is surrounded by a water jacket 18 and is in communication by a pipe 22 with a condensate reservoir 21, Fig. 1, a vacuum is established in the retort and reservoir, e.g. by repeatedly filling with water and emptying a 32 feet high tank 1 in communication by pipes 16 and 30 with the retort and the reservoir, the food is heated to drive off the water as vapour and simultaneously the wall of the retort is cooled by passage of cold water through the jacket 18, and periodically the condensed water draining from the retort by way of the pipe 22 into the reservoir 21 is, after shutting off communication between the retort and reservoir by closure of a valve 28 in the pipe 22, emptied through a drain pipe 24, the reservoir 21 being re-evacuated before it is again opened to the retort by re-opening of the valve 28. A shelving unit, Fig. 2, for supporting the food, preferably run into and out of the retort on rails 37, comprises hollow shelves 51 which are secured in the required positions on racks 44, Fig. 4, by pins 50 and are heated by passing steam from a header at the end of one shelf, through the channels of a corrugated plate 60, Fig. 6, welded to the top and bottom plates of the shelf, to a header at the other end of the shelf, and then by a pipe 54 to the next shelf. For preparing dehydrated food in round form there may be employed a tubular holder 61 having vent holes 63, Figs. 6 and 7, which holder is surrounded by a steam heated jacket 62 and is provided with spring plungers 64 for compressing the food as it shrinks on dehydration, the holder being supported within the retort on tracks 67.