| 摘要 |
1314858 Heat exchange crystallization BRAMEDA RESOURCES Ltd 23 June 1970 [27 June 1969] 30490/70 Heading BIG [Also in Division C1] A process for crystallising sulphur from its solution in a solvent which is immiscible with and more dense than water comprises passing said solution down a crystallisation zone in countercurrent flow to a stream of aqueous heat exchange liquid introduced at a series of points spaced vertically below the point of introduction of the sulphur solution, allowing the solvent and aqueous liquid to separate in the crystallisation zone to form an interface above the level of introduction of the sulphur solution, removing heat exchange liquid from a point above said interface and a slurry of crystalline sulphur in lean solvent from the bottom of said crystallisation zone and maintaining the temperature of the aqueous liquid introduced below that of the sulphur solution into which it is introduced and also below that of the aqueous liquid introduced at the next highest level and separating crystalline sulphur from the product slurry. A preferred embodiment of the claimed apparatus comprises a vessel 40 divided into a series of zones by baffle plates 46, each zone being provided with an agitator 43 and an inlet 50 for heat exchange liquid. Sulphur solution is introduced from line 82 and product sulphur slurry is removed through line 90, sulphur being separated from lean solvent in separator 94. Heat exchange liquid introduced through inlets 50 coalesces to form interface and is withdrawn via line 68 and the stream of liquid is then divided. One portion is recycled directly to inlets 50 via line 62 whilst the other is cooled by passing through heat exchangers 58 and 60 before returning to inlets 50 via line 56 where, by adjusting the ratio of liquid returned via line 56 to that returned via line 62, fine control of the inlet temperature can be obtained. Cold lean solvent from separator 94 may be passed to heat exchanger 60 via line 104 to cool the spent heat exchange liquid. |
