摘要 |
PURPOSE:To provide a method of combusting nitrogen containing combustible waste, comprising the steps of combusting nitrogen containing waste with introduction of less than a certain amount of primary air to a fluidized bed section, reducing NOx in the gas formed by the combustion of the waste with NH3 also contained in the formed gas, then introducing secondary air for combusting the uncombusted matters, thus reducing formation of NOx in the combustion gas, and converting NOx into innoxious N2. CONSTITUTION:Primary air for combusting waste and auxiliary fuel such as heavy oil are supplied respectively from lines 7 and 8, whereas nitrogen containing combustible waste is supplied from line 9. Fluidizing medium such as sand is used in bed portion 3. Amount of primary air introduced into the furnace is designed to be less than the amount of air containing theoretical amount of oxygen necessary for combusting the waste and auxiliary fuel. Uncombusted matter containing gas, formed by the combustion at the bed portion 3, is introduced at 650-850 deg.C into reducing section 5, where NOx in the gas is reduced to N2 through reaction with NH3, one of uncombusted matters contained in the gas, so that amount of NOx can be reduced considerably. The time requied for the gas to pass through reducing section 5 is designed to be greater than 1 second. Then, secondary air is supplied to oxidizing section 6 from lines 10A, 10B and 10C to combust the uncombusted matters completely. |