| 摘要 |
PURPOSE:To reduce the damage of a furnace wall, a furnace floor, etc. and to reduce production of NOX through prevention of the occurrence of incomplete combustion, by a method wherein steam is blown into a secondary air so that O2 concentration at an exhaust gas outlet is maintained within a given range. CONSTITUTION:An amount of a secondary air, supplied through a secondary air feed pipe 14 to the upper part of a combustion chamber 1, is controlled by a damper 15 so that O2 concentration (dry base) in exhaust gas at the outlet of a combustion chamber 1 is detected to maintain the resultant value at a specified value within a range of 4-10%. Namely, a flow rate control valve 18, located halfway along a steam feed pipe 17, is automatically regulated so that, through mixture of steam into a secondary air, O2 concentration is adjustable into a specified value B (%) within a range of 10-21%, and moisture content concentration C (%) in a secondary air after mixture of steam is brought to C=100B/ 21-100. This causes control of combustion of unburnt gas, decreases an amount of NOX produced, and simultaneously, further reduces production of NOX by a self-denitrating effect produced by water-gasifying reaction of steam to a carbon content in flame. |
