| 摘要 |
<p>PURPOSE:To decrease the amt. of the chemicals and resins to be used by providing means for detecting the flow rate of waste water, means for detecting the concn. of COD in the waste water and means for generating a signal for commanding washing. CONSTITUTION:A signal 56 for the concn. of COD in the circulation tank of an absorption column is determined from a signal 48 for the concn. of SO2 in the inlet of a desulfurizer 5 detected from a detector 28 for the concn. of SO2 in the inlet of said device, a signal 50 for the concn. of SO2 in the outlet of a desulfurizer 5 detected from a detector 29 for the concn. of the SO2 in the outlet of said device and a signal 51 for the flow rate of an exhaust gas detected from a detector 30 for the flow rate of the exhaust gas, in a computing element 37 for the concn. of the COD in the circulation tank of the absorption column. A concn. 57 for the concn. of COD is computed from a signal 52 for the flow rate of withdrawing a slurry from a circulation tank, a signal 55 for the flow rate of delivering a slurry from a gypsum tank and a signal 53 for the flow rate of sulfuric acid, in a computing device 38 for the concn. of COD in the gypsum tank. A signal 58 for the concn. of COD in a neutralizing tank is similarly obtd. in a computing element 39 for the concn. of COD in the neutralizing tank as well.</p> |
