| 摘要 |
<p>PROBLEM TO BE SOLVED: To stably secure the dehydration performance of gypsum and prevent abnormal accumulation of impurities by a relatively easy method while decreasing the amount of water discharged from a desulfurization apparatus even under such conditions that in the apparatus, finely particulate impurities are mixed in a large amount. SOLUTION: Sulfur oxides in a combustion flue gas are introduced into an absorption tower 2 to be absorbed by an adsorbent; the resultant calcium sulfite is oxidized in a circulation tank 7 and is recovered as gypsum in a primary gypsum dehydration apparatus 13a; and a part of overflow water (the supernatant side) of the dehydration apparatus 13a is supplied through a line 18 to a region in the course of dehydration in a secondary gypsum dehydration apparatus 13b. After a dehydrated gypsum layer mainly comprising gypsum is thus formed to a certain degree, a liquid containing particles having relatively small particle sizes is supplied from an absorbent-containing liquid to the dehydrated layer, thus enabling a fine-particle component to be efficiently removed from the process without enlarging the scale of the secondary gypsum dehydration apparatus 13b.</p> |
