| 摘要 |
<p>PURPOSE:To contrive safety driving, while neutralizing sulfuric acid gas to prevent the corrosion of the titled dust precipitator, by providing a feeder means for fly ash in the middle of a passage for introducing exhaust gas containing sulfuric acid gas from a coal burning boiler to said dust precipitator. CONSTITUTION:Exhaust gas formed in a boiler 1 is cooled with an air preheater 2, and dust is removed from it with the first dry electric dust precipitator 3. Thereafter, said gas is sent through a gas heater 4, a wet desulfurizer 5 and then the gas heater 4 again to the second dry electric dust precipitator 7, to further remove dust from it. On the basis of a value detected by a dust densitometer 8 provided in the middle of the passage leading to the second dry electric dust precipitator 7, a control valve 10 in a by-pass passage 9 is controlled to supply fly ash gathered by the first dust precipitator 3 from a device 11 for supplying fly ash. Hence, the second dust precipitator 7 is driven in a manner such that the concentration of said dust flowing into it does not become lower than a preset value, to prevent the corrosion of the dust precipitator caused by sulfuric acid gas.</p> |
