| 摘要 |
<p>PURPOSE:To keep absorption and removal of SOx contained in exhaust gas economically at high efficiency, by conducting operation which prevent increase in Ca<2+> conc. of absorbing soln. in lime-desulfurization process so as to decrease occurrence of scale trouble. CONSTITUTION:In operation of a wet desulfurization apparatus using aq. slurry contg. Ca cpds. such as lime stone etc. as an absorbing agent, the presence of substances, such as HC1 gas, which increases Ca<2+> concentration, in the exhaust gas decreases the desulfurizing ratio with passage of the operation time. Adjustment of Ca<2+> concn. of the absorbing soln. to 0.1% or under by addn. of NH4 cpd., e.g., (NH4)2SO4, (NH4)2CO3, to the absorbing soln. makes it possible to avoid the decrease in desulfurization ratio of the absorbing soln. Hence control of addn. of NH4 cpd. by measuring Ca<2+> concn. of the soln. through analysis of the absorbing soln. or filtrate from gypsum allows to keep high desulfurization ratio, consequently the desulfurization apparatus can be operated economically with decreased consumption of utility.</p> |
