| 摘要 |
<p>PURPOSE:To prevent the corrosion and clogging of an air preheater owing to the formation of NH4 salt by adding Ca(OH)2 slurry into the high-temp. waste gas between a dry denitrator and the air preheater and adsorbing away the SO3 in the gas. CONSTITUTION:The waste gas from a coal firing boiler 1 is conducted to a high- temp. electric dust precipitator 2, where the gas is removed of dust. After NH3 is added through a supply pipe 3, the gas is conducted into a denitrator 4, where NOx is converted to N2 and H2O. At the same time, part of SO2 is converted to SO3. In succession, the waste gas is introduced into a spray dryer 5. When Ca(OH)2 slurry is supplied into the gas and is allowed to react with the SO3 in the gas in the dryer 5, gypsum is formed; at the same time, the slurry is dried by the high-temp. waste gas to fine powder. The waste gas is conducted through an air preheater 7 and a gas-gas heat exchanger 8 into a wet desulfurizer 9, where the gaseous SO2 and said fine powder are removed. Thereafter the gas is released through a chimney 10.</p> |
