| 摘要 |
PURPOSE:To obviate hampering of voids (air permeability) by selecting the specific zone in the furnace where the effect that minus mesh fine ore (nut raw material) gives on voids from the past raw material charging hystersis and charging the classified nuts raw materials only in this zone. CONSTITUTION:First, the grain size distributions and voids of the respective zones in the radial directions in the furnace are estimated from the past raw material charging hysteresis by using a computer. From this estimated value, the zone where the voids epsilon become maximum even if nut raw materials are charged is found out and the specified amount of the unts raw materials are fed and charged to this zone. For example, the charging zone obtained through estimation by using a blast furnace of a furnace opening radius 3350mm is within the range of 0.5-0.9 from the center in the infinite radus of the furnace opening. Next, if nuts raw materials are charged by using the movable armor (point 0.3-0.6) of a bell-less charging device so that the nuts raw materials are dropped within this range, then the air permeablilty of the charge does not degrade. |
