| 摘要 |
1,188,542. Crystallizing. DTSTINGTON ENG. CO. Ltd. 19 Feb., 1968 [27 Jan., 1967], No. 4163/67. Heading B1G. A continuous crystallizer comprises an annular chamber having outer and inner walls 1 and 2 and containing a rotary composite helix 9. The composite helix comprises a narrow helical member 33 attached at its upper end to rotary driving means and a wide helical member 34 slideably connected at spaced points to the narrow member so as to enable limited lateral movement with respect thereto and continuous contact with one wall, preferably the inner wall, of the chamber. Member 34 is connected to member 33 by bolts 30 which pass with a clearance through member 34 and also pass through washers 37 and 37a of PTFE. The bolts may be spring-loaded (Fig. 3). Member 34 is provided on its minor faces with strips 38a and 38b of PTFE. The annular chamber is in three sections, being internally and externally cooled at the upper section, externally heated or cooled at the intermediate section, and internally and externally heated at the lower section. The liquid feed is introduced through inlets 23 in the intermediate section forming mother liquor, which is withdrawn through an outlet 24 in the upper section, and crystals, which are passed downwards under the action of the helix and are withdrawn as melt through an outlet 25 in the lower section.
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