| 摘要 |
<p>An ash melting type U-firing combustion boiler, wherein the volume of a combustion furnace (5) is set so that the temperature of the gas passing through a slag screen (4) separating the combustion furnace (5) from a heat storage furnace (6) positioned on the downstream side thereof can be maintained in such a temperature range that can normally function the slag screen (4) even when a supply air amount from burners (2) to the combustion furnace (5) is restricted to an air ratio of less than 1, the supply air amount from the burners (2) to the combustion furnace (5) is restricted to the air ratio of less than 1, pulverized coal is burned in the combustion furnace (5) with excess fuel to bring the inside of the furnace in a reduced atmosphere, and a temperature inside the combustion furnace (5) is raised near the ash melting point of coal to reduce the produced amount of NOx.</p> |
