| 摘要 |
PURPOSE:To effect most suitable combustion of even pulverized coal having a high fuel ratio, by a method wherein a passage for conveying pulverized coal with the aid of a primary air and a primary nozzle open to the inside of a furnace at the forward end of the conveying passage are divided into plural pieces. CONSTITUTION:A pulverized coal burner according to this invention consists of a primary nozzle, comprising a split primary nozzle 10 for injecting coal of low fuel ratio and a split primary nozzle 11 for injecting coal of high fuel ratio, a secondary air nozzle 12 communicated to a secondary resistor 8, and a tertiary air nozzle 13 communicated to a tertiary resistor 9. Pulverized coal 4 of a low fuel ratio, conveyed through a conveying pipe 60 togetherwith a primary air, is injected into a furnace through the split primary nozzle 10 after passing through an inner conveying passage 6, and is immediately evaporated and fired to start combustion. Meanwhile, pulverized coal 5 of a high fuel ratio conveyed through a conveying pipe 70 is injected into a furnace through the split primary nozzle 11 after through an outer conveying passage 7, but the coal is rapidly heated by the influence exercised by the combustion flame of the pulverized coal of the low fuel ratio to quickly start combustion. This stabilizes the flame and maintains it at a high temperature, and enables sharp reduction in the production of a unburnt content in resultant ash. |
