| 摘要 |
<p>PURPOSE:To enhance the CaCO3 dissolving reaction speed of a SO2-absorber, by detecting the amount of HCl in exhaust gas containing SO2, HCl and HF to add a stoichiometric amount of a Na-compound or K-compound to said gas blowing air in an absorbing solution. CONSTITUTION:Exhaust gas 1 containing SO2, HCl and HF from a coal firing boiler is guided to an exhaust gas treating tower 2 and SO2, HCl and HF are absorbed and removed by an absorbing solution. CaCO3 is supplied from a line 7 corresponding to the absorption amount of SO2 and, at the same time, Na2CO3 or K2CO3 is supplied from a line 8 in an amount corresponding to the stoichiometric amount with the amount of HCl. Air is blown into the tank 9 provided to the lower part of the exhaust gas treating tower 2 from an air nozzle 10 to absorb SO2 and formed sulfite is oxidized to sulfate. By this method, the dissolving reactivity of CaCO3 is easily restored even if an Al-ion or F-ion is dissolved in the absorbing solution and the reactivity of CaCO3 is enhanced.</p> |
