An improved method of and apparatus for the cooling, crystallization and phase separation of crystallizing hot liquids

摘要

PICT:0694804/III/1 PICT:0694804/III/2 Liquids capable of producing crystals on cooling are cooled within a centrifugal strainer-separator to produce crystals during their passage between the point of discharge of the feeding means and the screen of the centrifuge. Cooling is effected by exposing a large liquid surface to the air in the centrifuge and/or by feeding a cooling gas or liquid into the centrifuge. In addition the outer surface of the centrifuge screen may be cooled. As shown in Fig. 1, liquid is fed by line 2 to nozzles on a pipe 4 p within the rotor 5 of the centrifuge. Atomizing gas, which may be the vapour of a solvent for impurities, is fed to the nozzles by a pipe 7. In addition a cooling liquid, which may also be a wash liquid, is fed by line 10 to nozzles on a pipe 12 and spaced immediately behind the nozzles on pipe 4 (not, as shown for convenience, at 180 degrees distant). Fluid from a line 15 cools the outer surface of the rotor. Fig. 2 shows a modified nozzle in which cooling liquid is sprayed from annular tubes 20 surrounding the nozzles 19 from which the crystallizing liquid is sprayed.