| 摘要 |
<p>PURPOSE:To maintain the specified desulfurization degree for the charge fluctuation of a combustion apparatus and to decrease the consumed quantity of an absorbent by calculating the absorbent slurry quantity on the basis of the excess degree of the absorbent corresponding to SOx quantity contained in a waste gas, a forecast pH value after the prescribed period in an absorption tower and the aimed pH value. CONSTITUTION:The excess degree of an absorbent is output in a function generator 31 in accordance with SOx quantity output from a multiplier. The forecast pH value after (t) minutes is calculated by the first arithmetic device 32 out of the measured value of an absorbent slurry pH meter 20 plus an absorbent slurry flowmeter 19 and the aimed pH value after (t) minutes is calculated in the second arithmetic device 34 and both the two are inputted to a controller 35. The excess degree of absorbent sent from the function generator 31, the feedback control signal of pH value sent from a controller 27 and the forecast control signal of pH value sent from the controller 35 are added in an adder 36 to obtain the excess degree of absorbent slurry and the flow rate of the required absorbent slurry is calculated therefrom to control a flow rate control valve 15 of absorbent slurry.</p> |
