| 摘要 |
1,171,024. Freezing liquids. SULZER BROS. Ltd. 11 Jan., 1967 [11 Jan., 1966], No. 1449/67. Heading F4H. Frozen liquid is obtained in granular form by atomizing the liquid into a cold gas flow having a pressure greater than one atmosphere so that the droplets freeze without contacting any solid surface, further cooling the frozen droplets and then separating the frozen droplets from the gas flow. As shown, liquid is sprayed from an atomizer 5 into a chamber 2 and air from a blower 12 passes into the top of the chamber 2 via tubes 11 of a heat exchanger 3 and baffles 6 which impart to it a swirling motion. The granular frozen product from the chamber passes through a tube 16 of heat exchanger 3 to a cyclone separator 1 from which the product is discharged by a worm 23 and air returns to the blower via pipes 18, 19. Heat exchanger 3 comprises the evaporator of a refrigeration system 8, 9, 10. The system is maintained at super-atmospheric pressure by a compressor 15 supplying make-up air to the downstream side of the blower. In a first modification (Fig. 2, not shown), the pressurizing air from the compressor is supplied to the atmoizer which is in the form of an ejector and induces a flow of liquid thereto, part of the circulating air being passed through a fluid motor which drives the impeller. In a further modification (Fig. 6, not shown), two freezing chambers are connected to a common heat exchanger-separator unit and cold gas is passed upwardly through each chamber, throttling means being provided so that for freezing the gas pressure is low, while for ejecting the frozen product the pressure is increased. Preferably, freezing takes place in one chamber while ejection takes place in the other. The process may be carried out in serially connected freezing stages, separation taking place either between each stage (Fig. 3, not shown) or only after the final stage (Fig. 4, not shown). |
