General model of pulverized coal combustion ratio in blast furnaces

A general model of pulverized coal combustion ratio was put forward, which can calculate the kinetic parameters and combustion ratio based on coal industrial analysis. The accuracy of this model was verified by comparing with previous experimental data. Some factors influencing the coal combustion ratio were discussed. It is found that during the process of pulverized coal injection, the pulverized coal particle can reach the velocity of hot blast within 2 ms. In the blowpipe, due to the pulverized coal particle with short residence time and lower temperature, combustion reaction does not occur. When the pulverized coal particle enters into the raceway, the volatile is released instantly. The smaller the coal diameter is, the earlier the volatile will be released. The coal combustion ratio can be improved by decreasing the coal diameter or increasing the oxygen enrichment. When the oxygen enrichment increases 1%the combustion ratio increases about 2%. With increasing coal injection rate, the coal combustion ratio decreases. Therefore, when the coal injection rate increases, we should increase the oxygen enrichment and decrease the particle diameter appropriately to maintain the high combustion ratio.