| 摘要 |
PURPOSE:To dilute safely a reducing agent without decreasing the efficiency of a boiler or the like in a denitration device which is provided with a spray device of a medium for carrying the reducing agent on the front flow side of a flue having a denitrating catalyst by using the waste gas of a combustion device for said medium. CONSTITUTION:The outlet gas of, for example, a boiler 1, is conducted through a flue 2 into a denitration device 3. On the other hand, the waste gas which is increased in pressure with a ventilator 5 for recirculating gas in a flue 4 is supplied to a duct 6 for controlling the temp. of the reheating steam to the furnace bottom and a duct 7 for mixed combustion of the waste gas to be incorporated into air for combustion. NH3 as a reacting medium (reducing agent) is passed through a carburettor 9 from a liquid NH3 tank 8 and is thereby made into a gas which is mixed with the waste gas in a diluting gas piping 10. The gaseous mixture is sprayed from a nozzle 11 in the inltet of the device 3. The boiler waste gas removed of NOx by reaction in the device 3 is discharged through an electrical dust precipitator 12 from a chimney 13. The decrease in the temp. of the gas to be treated by the incorporation of the diluting air is thus eliminated and the decrease in the denitration efficiency is prevented. |
