1987 Volume 66 Issue 9 Pages 785-790
Pulverized coal combustion experiments of seven imported coals from Australia, Canada, China and South Africa have been carried out to estimate their com-bustibilities. The unburned carbon in flyash, the conversion ratio of fuel nitrogen to NO and the NO reduction by staging were estimated to ascertain the impact of coal properties. A down-fired 20cm ID tunnel furnace was used in this study. The experimental results as follows;
1) Because the fuel ratio (=fixed carbon/volatile matter) is closely related with weight percent of unburned carbon in flyash, it can be an important index in predicting unburned carbon in the coal-fired boiler.
2) The formation of NO is considerably influenced by not only the coal nitrogen content but the fuel ratio.
3) The percentage of NO reduction by staging is decreased with increasing the fuel ratio.