GB963170A - Freezing apparatus for liquids - Google Patents

Abstract

963,170. Ice-making. E. WILBUSHEWICH. Nov. 28, 1962 [Feb. 7, 1962], No. 45039/62. Heading F4H. In ice-making apparatus comprising moulds 1 having internal depending evaporators 2 and jacket evaporators 5 the evaporators are connected in series, evaporators 5 are connectible either to receive liquid refrigerant supplied by a pump 30 or to discharge liquid refrigerant to a receiver 17 and evaporators 2 are connectible either to discharge partly vaporized refrigerant to a separator 19 or to receive hot gaseous refrigerant from a line 14. Liquid refrigerant is supplied from a pressure reducing valve (not shown) through a line 13 to the lower part 18 of the separator 19 whence it is supplied to a header 32 by the pump 30, gaseous refrigerant containing entrained liquid being returned from the evaporators through line 21 to the upper part 20 of the separator 19 to which a suction line 15 is connected. Four batteries of moulds B1-B4 are shown, the moulds of battery B1 being connected for freezing of their contents by valve means comprising rotatable channels 34, 35, 36 and 37. For freezing, channel 35 is connected to a pipe 38 and one branch of a manifold 39 to supply liquid refrigerant from the header 32 to the evaporator 5 whence it flows through pipes 10 and a chamber 7 to the outer tubes of the evaporators 2 which enclose coaxial return tubes 6 leading to an upper chamber 11 and a conduit 44. Gaseous refrigerant from the latter is supplied to the pipe 21 through the valve channel 36. For defrosting, the valve channels are, as in battery B2, rotated to connect the hot-gas line 14 through channel 37 to the line 44 so that the hot gas flows successively through the evaporators 2, 5 and displaces liquid refrigerant therefrom, this liquid being supplied to the receiver 17 through manifold 39, valve channel 35 and line 16 to be stored therein under pressure. On completion of defrosting the valve is turned to the position shown for battery B3 where the manifold 39 is again connected to the receiver 17, this time through valve channel 34, and liquid refrigerant from the receiver is forced back into the evaporators which are connected to return line 21 through line 44 and channel 36. The valve is then turned through the position shown for battery B4, in which all connections are cut off, to the freezing position and the cycle is re-started. The receiver 17 is connected to the separator 19 by an arrangement comprising a float valve 23 and pipes 22, 24, 25 and 26 which allows excess liquid refrigerant to escape from the receiver while retaining gaseous refrigerant therein. In Figs. 2 and 3 (not shown), the connections to the mould evaporators are modified so that during defrosting hot gaseous refrigerant is first passed to the outer tubes of the internal evaporators rather than to the inner tubes 6 as above.