| 摘要 |
PURPOSE:To enable to circulate a part of exhaust gas into an incinerator by installing a circulation duct for exhaust gas which is branched off from a by- path duct and is connected to hoppers under burning fire grate, hoppers under after-burning fire grate, a cooling air inlet of the incinerator and an upper part of a main ash chute. CONSTITUTION:During operation, reduction of NOx concentration in fuel exhaust gas is achieved by turning down a damper 17 in a primary duct 19 and reducing wind volume from a forced draft blower 16. On the other hand, oxygen in fresh air from a blower 49 controlling incinerator temp. increases the oxygen concentration in the exhaust gas and as a result, NOx concentration increases. By closing a damper 47 in a by-path duct 46 and opening damper 48 at the same time, a part of exhaust gas with low O2 concentration which flows in a secondary exhaust gas duct 42 from an electric precipitator 41 is enabled to flow reversely in the by-path duct 46 before going into a stack 45 and then is enabled to flow in an exhaust gas circulation duct 52. The exhaust gas is supplied and circulated to hoppers 12, 13, 14 corresponding to a burning fire grate 5 and an after-burning fire grate 6 via exhaust supply ducts 55, 56, 57 and burns waste after being mixed with a fresh air. |
