| 摘要 |
<p>PURPOSE:To prevent the lowering in desulfurization capacity, in treating exhaust gas containing SO2, HCl and HF, by attaining the coexistence of a Ca-compound as a SO2-absorbent, a Mg-compound in an amount corresponding to the stoichiometric amount of HCl and a specific concn. of a Mn-ion. CONSTITUTION:After the amounts of SO2, HCl and HF in exhaust gas 1 from a coal burning boiler are detected by a detection apparatus 3, said exhaust gas 1 is guided to an exhaust gas treatment tower 2 where an absorbing solution is sprinkled to absorb SO2, HCl and HF while the treated gas is exhausted as purified gas 6. CaCO3 is supplied from a line 7 in correspondence with the SO2-absorbing amount and Mg(OH)2 corresponding to the stoichiometric amount of HCl is supplied from a line 8. In addition, MgSO2 is added so as to adjust the Mn-ion concn. in the absorbing solution to 10-400mg/l. By allowing the Mn-ion to coexist, the dissolution of CaCO3 is not inhibited even if the additional amount of the Mg-compound is made smaller than stoichiometric amounts of HCl and HF, and desulfurization capacity is not lowered.</p> |
