GB697471A - Ice making machine and method - Google Patents

Abstract

697,471. Ice-making. LEE, A., and LIEBERMAN, E. Nov. 6, 1950, No. 27097/50. Class 29. Water is frozen in open-ended tubes 11 -14 to produce columns of ice 90, the tubes are then heated to release the ice and air pressure applied to one end of the columns to eject them from the tubes against abutments 82 which break the ice into small pieces. The tubes 11-14 depend from a pan 15 to which water is supplied from a pipe 16 under the control of a float valve 19 to fill the tubes which are connected by pipes 23 to compressed air accumulators 22. During the freezing cycle refrigerant from the compressor 27 passes to the condenser 28 and receiver 33 and by pipe 34 to an expansion valve 35 whence it is supplied by a pipe 36 to the bottom of a jacket 21 around the tube 11. From the top of the jacket the refrigerant is supplied by a pipe 37 to the bottom of a jacket 21 around the tube 12, and so on through the jackets of the other tubes to a suction pipe 38 leading back to the compressor at 39. The expansion valve 35 is controlled by a thermostat 79 on the suction pipe 38. An air compressor 65 is also operated to supply air under pressure to an air storage tank 24 and during freezing this air is supplied through a low pressure regulator 58 solenoid valve 61, pipe 53, leader 54, restrictors 55 and non-return valves 57 to the compressed air accumulators 22. The air, under low pressure, thus maintain the bottom of the water column at the level shown in Fig. 5, and bubbles through the water so that clear ice is formed. When the water in the tubes has nearly all frozen a thermostat 78 on the jacket 21 of the tube 11 closes a switch to start the motor of a timing device, which first de-energises the solenoid of the low pressure air valve 61 closing this valve and stopping the supply of air to the accumulators 22. This allows the water in the central part of the columns to freeze. The timing device then opens a hot gas valve 42 and a high pressure air valve 64. Hot refrigerant gas from the compressor 27 then passes through a pipe 41 to jackets 43 on the upper ends of the pipes 11-14 and thence by a pipe 45 to jackets 46, on the lower ends of the tubes. From the jacket 46 a pipe 48 leads to a T-piece 49 in the pipe 36 and the hot gas then follows the same course as the refrigerant gas in the freezing cycle through the jackets 21 to the suction line 38. Opening of the valve 64 causes a high air pressure to build up beneath the ice columns to force them upwardly as soon as they are released by the hot gas. The upper ends of the columns are broken off by inclined plate 82 secured to the wall of the pan 15, and the pieces are directed by hood 95 and guide 96 into a bin 85. After the ejection of the ice columns is completed the timing device closes the valves 42, 64 starting the freezing cycle and allowing water to flow into the tubes 11 -14. Low pressure air valve 61 is then opened and the motor of the timing device stopped ; another cycle of freezing and harvesting then takes place. A thermostat 104 stops the machine when the bin 85 is filled with ice. The ice may be crushed by rotatable breaker members, spiked wheels, or a fixed knife against which the ice column is forced by the air pressure.