GB1263452A - Improvements in or relating to the manufacture of ice - Google Patents

Abstract

1,263,452. Ice making. M. K. REFRIGERATION Ltd. 13 Feb., 1969 [13 Nov., 1967], No. 51628/67. Heading F4H. Ice blocks are formed by spraying water from a tank 33 through a perforated screen 37 on to an inverted refrigerated ice tray 25. Unfrozen water falls back into the tank, while harvested ice blocks are intercepted by the screen. During spraying, no water is added to the tank 33 so that spraying terminates when the tank is emptied. In the absence of a spray, the tray temperature falls and a temperature senser at the tray switches on tray heating means, deenergizes the spraying pump 32, and opens a valve 35 to allow water to be supplied to the tank 33 under the control of a float valve 34. When ice has been harvested the tray temperature will rise to a point at which the senser restarts the tray refrigeration, closes the valve 35, and reenergizes the pump 32. In alternative systems, a temperature senser is located so as to be contacted by ice when the tray is full, and the whole operation is controlled by a timer. The tray may be cooled by a compression-condensation refrigeration system and tray heating may be accomplished electrically or by passing hot gas direct from the compressor to the evaporator. The tray may be cast and have evaporator tubes embedded in it or may be of the form shown in Fig. 3 in which evaporator tubes 23 cool a partitioned tray through its base wall 24. The tray walls are notched at 30 to allow air to reach the upper sides of the ice blocks during harvesting thereby promoting free movement of the blocks.