High rate coal injection of 218kg/t at Fuhuyama no 4 blast furnace

Al Fukuyama No. 4 Blast Furnace, a pulverized coal injection system with a capacity of 72 t/h was installed at the end of April 1994. In October, six months later, the highest coal injection was carried out. Eventually, a maximum injection rate of 230 kg/t and monthly average of 218 kg/t was successfully attained. The main features making the high rate injection of pulverized coal possible are the following: (1) high combustion efficiency with the newly designed eccentric double lance; (2) use of Hybrid Pelletized Sinter with superior reducibility and melting characteristics; and (3) optimum control of gas flow distribution to keep in-furnace permeability. Moreover, the in-furnace phenomena in the lower part were analyzed by the deadman probe, and it was confirmed that the good permeability in the deadman could be maintained by the improvement of injection and burden properties.