GB636635A - Improved method and apparatus for intermittent cooling - Google Patents

Abstract

636,635. Refrigerating. LIGHTFOOT REFRIGERATION CO., Ltd., and GARROD, C. E. Oct. 24, 1947, No. 28463. [Class 29] Apparatus for cooling milk &c. of the kind in which ice is formed during periods when cooling is not required to increase the refrigerating capacity during active periods, comprises a tank 1 containing superposed trays 10 over the surfaces of which flows water from a pipe 9, the water in the tank being circulated by a pump 6b through a three-way valve 7 to the pipe 9 either directly to form ice on the trays or through the milk, &c., cooling apparatus. The insulated tank 1 contains water up to the level A and a submerged pump 6b circulates this water, during periods when milk cooling is not required, through a pipe 6f, the three-way valve 7 and a pipe 8 to the spray pipe 9 arranged above the superposed inclined trays 10 so that the water flows in a film over the trays successively and is frozen thereon by refrigerant evaporator pipes 10b supplied from a refrigerating unit 5 carried by the lid 4. When ice has formed on the trays to a predetermined thickness the pump and refrigerating unit are switched off by a thermostatic control or by a switch 6d operated by a float 6e. When it is desired to cool a batch of milk the three-way valve 7 is turned and a switch operated to start the pump and refrigerating unit, the water from the tank 1 passing by flexible connections to the milk cooler and returning to the spray pipe 9 so that the melting of the ice aids the cooling. The trays 10 are formed of two plates welded together, one plate being provided with a zig-zag channel to form the refrigerant passage 10b. Refrigerant from an expansion valve 5e is supplied by pipes 11a, 11b to the lower ends of the second tray and the lowermost tray, and return pipes 12, 12a extend from the upper ends of the topmost tray and the third tray. A row of holes in each tray allows leakage of water to form ice also on the undersides of the trays. The normal water level in the tank is maintained by an overflow pipe 1f with a drain 1e. The milk cooler may be a two-stage one in which the milk is pre-cooled by water from the mains or a well and then cooled by the circulating cooling medium.