| 摘要 |
1,195,363. Freeze drying; freezing liquids. STRUTHERS SCIENTIFIC & INTERNATIONAL CORP. 19 June, 1967 [17 June, 1966]. No. 27112/66. Headings F4G and F4H. A comestible liquid solution is pre-frozen by first cooling in a conventional crystallizer 11 surrounded by a refrigerated jacket 14, removing ice crystals by a centrifuge 18, and passing the cooled solution into a prilling column 28 in periodic pulses through a spray head 26 in countercurrent to a flow of recirculated and cooled gas, e.g. nitrogen. The frozen particles or prills 37 so formed pass via valved conduits 42, 51, 54 and a cold insulated hopper 43 into a vacuum drying chamber 41 for sublimation of the frozen moisture content. The prills are carried in a circuitous path through the chamber 41 by trays 55 pivotally suspended at their end walls by shafts extending inwardly from spaced positions about the periphery of two rotary tray support discs 63 mounted on driven shafts 57. The chamber is connected to a vacuum source (not shown) and includes moisture condensing means, and each tray includes an electrical heating coil in its base. The trays are tipped by a spring arm 70 to dump the dried prills into a product hopper 71 at the base of the chamber.
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