| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method and apparatus for flue gas desulfurization whereby the reliability of apparatus is secured at a low equipment cost without increasing the chlorine concentration, i.e., a cause of troubles of a desulfurization apparatus. SOLUTION: In this method, after a flue gas 1 discharged from a boiler is contacted with an absorbent liquid containing limestone, etc., in an absorption tower 2 to treat sulfur oxides in the flue gas 1, gypsum as a by-product is recovered from the absorbent liquid. The chlorine concentration in the absorbent liquid can be kept at a specified value or lower by adjusting the water content of gypsum recovered from the absorbent liquid to the amount of chlorine absorbed by the absorbent liquid by adjusting the number of revolutions of a gypsum dehydrator 12. The amount of chlorine absorbed by the absorbent liquid is calculated in advance from a boiler fuel signal 24 changing with the difference in load on a combustion apparatus, the kind of used fuel, etc.</p> |
