Sulphur dioxide removal with scrubber scaling prevention - by controlled soln seeding to control level of supersatd

摘要

is removed from gas streams by (a) liquid scrubbing to form a stream of sulphite and/or sulphate soln. (b) recycling at least part of the scrubbing medium (c) adding seed crystals to at least part of the scrubbing medium such that a particle balance is provided and the level of supersatd of the sulphite/sulphate is controlled below a certain level and the sulphite/sulphate prod. particle size is controlled and (d) controlling the rate of seed crystal addition such that the total number of seed crystals (including those randomly formed) in the scrubbing medium circulation path is equal to the crystals removed. Method of controlled desupersatn. prevents plant scaling.