| 摘要 |
<p>PURPOSE:To simplify the equipment of succeeding pH regulating stages, etc. by providing a vertical partition plate in a circulating tank of an absorption tower, taking out a slurry of an absorbent with reduced pH from the separated part, and supplying the slurry into a gypsum recovery stage. CONSTITUTION:A vertical partition plate 41 is provided in a circulating tank 5 of an absorption tower, and a small-capacity separated part 50 is formed. A circulating slurry is sprayed from a spray 40 of an absorption tower 3, and absorbs SO2 in the waste gas. The pH of the slurry is reduced thereby. The greater part of the slurry after absorption falls into the part 51 at the outside of the partition plate, and the remaining part into the separated part 50. Meanwhile, a new slurry 22 of the absorbent is supplied into the part 51, and supplied into the absorption tower 3 by a pump 6. Since the slurry 22 of the absorbent is not incorporated into the part 50, the pH of the slurry in the part 50 is reduced. The air 24 is supplied by a blower 52 to make the slurry in the part 50 into gypsum. Accordingly, the consumption of sulfuric acid for neutralizing the unreacted CaCO3 which is added into a reaction tank 9 can be reduced, and an oxidation tower can be omitted.</p> |
