Patent GB-717575-A (GB)
Title: A process of production of ice in blocks and apparatus for operating the same
IPC: F25C1/06
Filed: 1951-03-12
Abstract: 717,575. Ice-making WILBUSHEWICH, E. March 12, 1951 [Sept. 25, 1950], No. 5900/51. Class 29  In ice-making apparatus of the general' type described in Specification 691,197, each rectangular mould has one or more additional evaporators of circular crosssection depending into it, the hot gaseous refrigerant being passed through theseevaporators also during harvesting. On a base 5 are mounted rectangular or square moulds 7 embraced by a common insulated refrigerating evaporator jacket 9 having a refrigerant supply conduit 26 and a suction conduit 27 connected to a separator 30. The jacket 9 may contain baffles. The moulds are interconnected by tubes 44 45 and are filled from a header 15 or a reservoir by a pipe 13a leading into one mould and including a valve 14a. Alternatively, each mould may have a feed pipe 13 and valve 14 which may be supplied each from its own reservoir or from the common header 15. The moulds have each a counterweighted bottom 16, 18 hinged at 16a and discharged blocks fall on to a frame 19 having shoots 20 terminating in stops 23. The water in the moulds may be agitated or subjected to a vacuum during freezing. The water may be introduced into the mould by a spray rose. One or more supplementary evaporators 46 of circular cross-section are inserted into one or more moulds and comprise each a liquid refrigerant supply tube 47 connected to the conduit 26 by a tube 49. The evaporators 46 have a common suction conduit 48 connected to the separator 30. In operation, liquid refrigerant from a pipe 34 connected to the condenser passes through a non-return valve 33 to the conduit 26 and to the evaporators 9. 46 whence vapour passes through pipes 27, 48 to the separator 30 and through a four-way valve 38 to a collector 36 leading to the compressor suction. The last part of the water to freeze is in the central top part of the charge and, when this reaches freezing temperature, a thermal bulb 24 actuates a control 42 to cause valve 38 to change over. Compressed refrigerant vapour then passes from a distribution duct 37 to the separator 30 whence it flows by pipes 27 and 48 to the evaporators. Valve 38 also connects the duct 37 to a receiver 29 by a pipe 29 and,. due to this equalization of pressure, the compressed gas drives the liquid refrigerant out of the evaporators through pipes 49 and 26 to the bottom of the separator whence it runs into the receiver by a pipe 28. The compressed gas also closes the valve 33. When the blocks have been thawed, the mould'bottoms swing open to contact a member 43 which actuates the valve 38 to connect the separator once more to the suction collector 36 and to close the equalizing connection 35. The high pressure in the receiver 29 then forces the stored liquid refrigerant up the pipe 28 and through pipes 26, 49 to the evaporators, the reduced pressure in which permits the valve 33 to open again. Meanwhile the counterweighted bottoms have closed and, when they have frozen in place, the lower temperature in the mould causes a thermal bulb 25 to actuate a control 39 which opens the water valves 14 or 14a to fill the moulds. When the water reaches the prescribed level in the moulds a thermal bulb 40 actuates a. control 41 which closes the valves 14 or 14a. The control 39 may instead be actuated by the movement of the mould bottom through a time-delay device. The refrigerant level in the evaporators can be gauged by the frost level on a sighting tube 32 between the top and bottom of the separator 30.