| 摘要 |
<p>PURPOSE:To prevent the release of NOX-contg. waste gas in the stage of startup and shutdown of a dry type denitration device using NH3 by providing opening/closing means for conducting and interrupting the waste gas and similar opening/closing means for air in a waste gas introducing passage from a waste gas source. CONSTITUTION:When a denitration device is started, a damper 17 on a gas side is held closed and a damper 18 on an air side is held open. When a fan 15 is started, air is introduced through the damper 18. A heater 5 is then operated to admit heating air into a reactor 13, thereby heating up the reactor. When the reactor 13 attains a prescribed temp., a temp. detector 7 detects the temp. and a shutoff valve 11 is opened by the signal thereof to feed gaseous NH3 from an NH3 supply device 8 into the reactor; at the same time, the damper 17 is opened and the damper 18 is closed. The waste gas from a waste gas source 1 is thus denitrated in the reactor chamber 13. The shutdown of the denitration device is accomplished by stopping the heater 5, then the temp. of the waste gas and the temp. of the reactor 13 decrease. The decrease in said temp. is detected by the detector 7 which stops the signal output, thereby closing the valve 11 and the damper 17 and opening the damper 18.</p> |
