| 摘要 |
PURPOSE: To reduce the quantity of dust in waste gas fed into a dry desulfurizing/denitrifying device and to reduce driving power by recycling off gas into waste gas in the upstream side of an electrostatic precipitator. CONSTITUTION: Off gas containing SO2 and SO3 which have not been removed by a byproduct recovery device 11 is recycle-injected into inlet waste gas of an electrostatic precipitator 3. In this way, SO3 in the off gas is stuck on dust in waste gas and the dust is collected and removed by the electrostatic precipitator 3. Therefore, since the quantity of SO3 at the inlet of an adsorber 7 is remarkably decreased and the quantity of formed ammonium salt is decreased, the ammonium salt is prevented from being stuck and deposited on an inlet louver 13 to block a gas flow passage. Further, the electric resistance of the dust is lowered to improve dust collecting performance in the electrostatic precipitator 3. |
