Volodymyr Kochura

Abstract:

Domestic and foreign experience shows that one of the key prerequisites for using pulverized coal injection (PC) in blast furnace smelting is ensuring that the combustion of the PC is completed within the tuyere zone. Thus, monitoring the degree of combustion of this fuel is an important problem. Various methods and instruments are used to analyze PC combustion in the tuyere zone experimentally. It is proposed that the completeness of combustion of pulverized coal fuel injected into the hearth of blast furnaces be determined by petrographic analysis of the content of unburned coal particles in the top dust and slag and chemical analysis of the dust and slag. Theoretical and experimental research on PC burning process under conditions of raceway have been carried out. Methods and designs for intensifying have been developed. Industrial tests of these methods have shown the possibility of a considerable increase of PC combustion degree under high PC consumption. The industrial use of PC is accompanied by an increase in the amount of heat lost to the environment due to the intensified operation of the furnace. The injection of PC into the tuyere zone increases thermal radiation because of the formation of a luminous flame with a high emissivity. The result is overheating of the combustion products in the hearth, redistribution of temperature over the height of the furnace, and a significant increase in heat loss. Effect of coal composition on its use efficiency in blast furnace operation has been examined. Technical and economical parameters of blast furnace operation when injecting PC from different coals have been studied. Recommendations for coal grinding and method of complex compensation for the changes in the technological regime have been developed.