| 摘要 |
PURPOSE:To realize high temperature ash melting combustion in the primary combustion chamber with a small amount of air and reduce nitrogen oxides from generating in the secondary combustion by chamber by supplying enough amount of air necessary for combustion forming the combustion zone in a furnace into two divided zones performed within individual chambers respectively in a pulverized coal combustion equipment installed in a boiler or the like. CONSTITUTION:The combustion zone in a furnace comprises the primary combustion chamber 1, the secondary combustion chamber 2, a throat connecting said chambers 1 and 2 with each other and the like. Pulverized coal-air mixture is blown into the primary combustion chamber 1 through a pluverized coal- primary air supply pipe 5 at the maximum flow speed of about 100m/s and preheated air with the maximum temperature of about 700 deg.C is also blown into the primary combustion chamber 1 through a secondary air draw-in pipe 6 at the flow speed of about 100m/s. On the other hand, tertiary air is blown into the secondary combustion chamber 2 through a tertiary air draw-in pipe 11 so as to bring the excess air ratio within the secondary combustion chamber 2 to about 0.8-0.95. In the combustion chamber 1, the pulverized coal is collected to an ash pit 4 by means of cyclone effect. In the combustion chamber 2, the pulverized coal-air mixture is cooled, when passing through the throat 3, by means of a cooling pipe 9 and as well as prepared to have the predetermined excess air ratio with the air supplied from the draw-in pipe 11. |
