Patent GB-741753-A (GB)
Title: Process and apparatus for making ice
IPC: F25C1/06
Filed: 1953-05-22
Abstract: 741,753. Ice-making. GES. FUR LINDE'S EISMASCHINEN AKT.-GES. May 22, 1953 [May 23, 1952; April 28, 1953; April 30, 1953; May 2, 1953], No. 14544/53. Class 29. In an ice-making machine wherein the ice is formed in vertical tubes cooled by an evaporator jacket, liquid refrigerant not evaporated in the jacket is withdrawn by a pump and recirculated to the jacket. As shown in Fig. 2, water to be frozen is supplied by pipes 15 and a pump 14 to the freezing tubes 12, excess water being collected in a vessel 13 for recirculation, makeup water being supplied by a pipe 27. Liquid refrigerant from the condenser enters a separator vessel 20 by a pipe 23 and flows through pipe 28 to a collecting vessel 16. Pump 17 supplies refrigerant from vessel 16 to spray nozzles 18 in evaporator jacket 11 and inevaporated refrigerant drains from the evaporator to the vessel 16 through pipe 19. A cutter 24 for the harvested ice is provided. Freezing in the lower ends of the tubes 12 is prevented by an air chamber 26 which may be closed or may be supplied with hot air. As shown in Fig. 6, pump 17 supplies liquid refrigerant from collecting vessel 16 to the bottom of the evaporator into a space 30 from which the liquid flows upwardly while evaporating between the tubes 12 and auxiliary jackets 29. Excess liquid overflows the top 32 of jackets 29 and returns to the collecting vessel through pipe 19. During ice-making, a compressor 38 withdraws vapour from the separator vessel 20 and supplies it to condenser 39 and receiver 40 from which the liquid flows to collecting vessel 16 through expansion valve 41. When harvesting is required pump 17 is stopped whereupon the evaporator empties into the collecting vessel through pipe 19 and through the pump 17. Valves 44, 46 in the . compressor suction and exhaust pipes are closed and valves 42, 45 are opened. Hot vapour from the compressor then passes through pipe 43 and valve 42 to the evaporator to thaw off the ice from the tubes, the resulting refrigerant condensate draining into the vessel 16. The hot vapour is derived from the liquid in the condenser and receiver and is withdrawn therefrom by the compressor through the open valve 45. In a modified harvesting arrangement, Fig. 5 (not shown), only the pipe 43 and valve 42 are provided, the hot gas being supplied as before through valve 42 to the evaporator and being withdrawn therefrom by the compressor. The Specification describes with reference to Figs. 8-10 (not shown), installations having a plurality of sets of tubes which are harvested and refrigerated out of step with one another. An alternative means for preventing ice forming in the lower ends of the tubes is shown in Fig. 7. Water to be frozen flows through pipe 50 and valve 49 to a chamber 48 surrounding the tube ends. Water s prevented from contacting the bottom plate 51 of the evaporator jacket by the provision of an overflow in the chamber so that ice is not formed on the bottom plate. The water drains from the chamber through pipe 52 to the water vessel 13. Valve 49 may be opened or closed during the harvesting phase. Specification 253,868, [Class 29], is referred to.