| 摘要 |
<p>PROBLEM TO BE SOLVED: To increase and decrease in advance flow rate of an absorbent slurry to an absorbing column in accordance with timing of starting and stopping of a circulation pump and to suppress fluctuation in pH in the absorbing liq. as little as possible. SOLUTION: When a fixed no. operation where a required no. of circulation pumps are operated is performed, based on the detected flow rate A of desulfurization gas, concn. B of SO2 at the inlet of an absorbing column, pH of the absorbing liq. and concn. E of an absorbent slurry, a set flow rate 28 of the absorbent slurry being necessary for holding the pH of the absorbing liq. to a set pH value is obtd. and controlling is performed in such a way that the flow rate D of the absorbent slurry becomes equal to the set flow rate 28 of the absorbent slurry. In addition, when either of stopped circulation pumps is started to drive, or when either of operated circulation pumps is stopped, the set flow rate 28 of the absorbent slurry is increased or decreased by a required amt. from a fixed no. operation for a required time in advance and the flow rate D of the absorbent slurry is increased and decreased.</p> |
