| 摘要 |
PURPOSE:To efficiently remove ammonium compounds by roughly removing coal ashes from the waste gas of a coal-firing boiler by subjecting the same to high-temp. dust precipitation then denitrating the same by an ammonia catalytic reduction system, thence removing the remaining coal ashes through low-temp. dust precipitation. CONSTITUTION:The waste gas of a coal-firing boiler is first removed of dusts in a high-temp. dust precipitator 2, after which it goes through a denitrating device 3, and an air preheater 4 and is removed of dusts in a low-temp. dust precipitator 5. The coal ashes captured in the dust precipitator 5 are charged via an ash hopper 13 into a thermal decomposition furnace 14 for ammonium compounds. The high-temp. combustion waste gas of the boiler 1 is conducted into the furnace 14 as a heat source thereto and the thermal decomposition of ammonium compounds is effected at 50-700 deg.C, more preferably 350-700 deg.C temperatures. The coal ashes after the thermal decomposition and the decomposed gas are separated by a solid-gas separator 16. The decomposed gas is returned to the stage before the denitrating device 3 and is reused as an NH3 source. |
