| 摘要 |
<p>PURPOSE:To perform desulfurization and denitration with high efficiency without subjected to the effect of SO3 while preventing the corrosion and clogging of an apparatus accompanied by the formation of acidic ammonium sulfate when exhaust gas containing SO3 at high concn. is desulfurized and denitrated, by preliminarily removing SO3 in exhaust gas by bringing SO3 in said gas into contact with an absorbing agent. CONSTITUTION:Exhaust gas 11 containing SO3, SO2 and NO2 at high concn. is introduced into an SO3 absorbing tower 1 and brought into contact with an absorbing agent such as a limestone slurry from a line 13 to absorb and remove SO3 in exhaust gas 11. The byproduct is withdrawn from the bottom part of the SO3 absorbing tower 1 and sent to an absorbing agent slurry tank 6. NH3 is injected in the exhaust gas, from which SO3 was removed, from a line 21 and NOx is reduced in a denitration apparatus 2 packed with a catalyst. Subsequently, exhaust gas is sent to a temp. falling wet desulfurization apparatus 4 through a heat exchanger 3 and SO2 is removed by the absorbing agent slurry. The purified exhaust gas is discharged to the open air through a line 41.</p> |
