| 摘要 |
<p>PURPOSE:To further desulfurize SOx in waste gas by re-utilizing excessive CaCO3 in a desulfurizing agent, by spraying water into the waste gas from a fluidized bed boiler for performing in-furnace desulfurization to react the scattered desulfurizing agent from the fluidized boiler and SOx before dust collection. CONSTITUTION:The sulfur component in coal within the combustion furnace 1 of a fluidized bed boiler is reacted with limestone to form anhydrous gypsum while the sulfur component in coal burning in the second stage of a two-stage combustion system for suppressing the formation of NOx is issued from the furnace 1 as SOx. Dust from the furnace 1 is collected by a multi-cyclone 2 and sent to a re-combustion furnace 3 while the waste gas of said furnace 3 is sent to a multi-cyclone 4. The gas passing the cyclones 2, 4 is cooled by a gas/air heater 5 and, thereafter, water is sprayed into the cooled gas by a spray dryer 7 to increase the humidity thereof in a water unsaturated range while SO2 in the waste gas and quick lime in dust are reacted. Subsequently, the dust is collected by a filtering type dust collecting apparatus 5 and the desulfurized and dust removed waste gas is exhausted from a chimney 10.</p> |
