| 摘要 |
<p>PURPOSE:To automatically control the concn. of sulfite in a reaction liquid to a desired value, by adjusting the supply amount of the sulfite-containing solution and that of the additive added to the reaction liquid from the deviation signal of the detection signal of the concn. of sulfite in the reaction liquid containing sulfite and a set value. CONSTITUTION:For example, the sulfite-containing solution formed by desulfurization treatment of SO2-containing exhaust gas is supplied to a reaction tank 100 from a line 101. When sulfite is reduced, an oxidizing agent such as air or H2O2 is supplied to said reaction tank 100 from a line 102 as an additive and, when receives conversion reaction, Ca(OH)2 is supplied thereto as an additive from said line 102. The reaction liquid is continuously withdrawn from a line 104 to be introduced into a sulfite detector 105 and a sulfite concn. signal is sent to a sulfite regulator 106. A flow regulator 107 receives the deviation signal of a sulfite concn. set value and the detection value and the signal from a flow meter 108 and adjusts the opening degree of a valve 109 to adjust the supply amount of the sulfite-containing solution.</p> |
