Patent GB-718240-A (GB)
Title: Improvements in and relating to a process and plants to produce and harvest ice, andice blocks obtained thereby
IPC: F25C1/06
Filed: 1952-11-05
Abstract: 718,240. Ice-making. WILBUSHEWICH, E. Nov. 5, 1952, No. 27894/52. Class 29 In ice-making apparatus comprising upwardly - tapering moulds 1 having hinged discharge bottoms 7, liquid refrigerant is fed from a liquid pipe 25a through an expansion valve 28 and a branch pipe 25 to a downwardly-extending evaporator 24 within the mould, excess refrigerant flowing by pipe 68 to an external evaporator 3, the pipe 68 being connected to the suction pipe 26 of the compressor through a solenoid valve 27a. Assuming that an ice-block has just been discharged through the bottom, the latter will be raised bodily by spring 12 raising its pivot and swung up by spring 9. The former action opens a switch (not shown), connecting wires 39, 40 so that valve 38 for hot gas is closed and suction valve 27a is opened. Liquid refrigerant is then fed to evaporators 24, 3 in series to cause residual moisture in the 'system to freeze the bottom 7 to the bottom plate 6 of the mould. When a low enough temperature has been attained, a thermal element 21 responsive to the mould temperature actuates to supply current to a solenoidoperated water-supply valve 23 which opens to supply water into the mould from the bottom through pipes 18, 16, 13. When the mould is sufficiently filled, a float valve 17 rises to cut off the supply of water and break the circuit to water-supply valve 23 at 22. Because evaporator '24 does not extend right to the bottom, the lower part of the mould contains trapped water near the end of the freezing stage. Expansion of this water forces the bottom 7 bodily to position 7a. This makes the switch joining wires 39, 40 so that suction valve 27a is closed and hot-gas valve 38 is opened, the gas passing into the evaporators 24, 3 to free the ice and displace liquid refrigerant from evaporator 3 through pipe 31, pipe 72 (Fig. 13) and solenoid valve 72a to an accumulator 33 associated with the condenser 34 or to an independent accumulator. The freed ice pivots the bottom 7 downwardly and falls, the cycle being thus completed. Clear ice is attained by supplying the mould with compressed air through a pipe 14. The hollow core of the ice blocks may be filled with water which freezes due to the excess cold of the rest of the block, the make-up water being, if desired, supplied to the core by ‹way of the surface of evaporator 24 to pre-cool it. Pipes 68, 31 and evaporator 3 may be common to a battery of moulds. Instead of making the pivot of the bottom 7 vertically slidable, it may be fixed and the bottom is thin and resilient so as to flex under the ice pressure. The discharged ice may fall on to a trolley 42, Fig. 5, running on rails 44 and having the supporting and guiding surface shaped as shown. If several batteries of moulds are mounted on one frame over the rails 44, the trolley can be justified under each battery in succession. An alternative form of trolley, Fig. 12, comprises a base 71 carrying a vertically reciprocable ice-carrying platform having blocks 69a sliding in vertical frames 69 of each battery. These frames are cut away at 69b so that the trolley is free to move only when the blocks 69a are opposite the parts 69b, i.e. when the platform is lowered The various valves may be actuated manually. As shown in Fig. 7, each battery comprises moulds 63 in an insulated casing 62 and warm or cold air is circulated around them by a fan 66 during the harvesting or freezing stages. The pipes 68 act as baffles to divert the air towards the moulds or they may be in contact with the mould walls. Electric or other heaters may be provided within the casing 62. Fig. 9 shows in plan an arrangement having an outer evaporator A and five inner evaporators G, F. An arrangement of internal evaporators in a rectangular or triangular mould is also described with reference to Figs. 10 and 11 (not shown). Specification 691,197 is referred to.