Abstract
Fundamental aspects of the hot metal flow in the blast furnace hearth during tapping have been studied for the better control of the hot metal flow to prolong furnace life.
Blast furnace hearth is regarded as a packed bed of coke with considerably good permeability in terms of metal flow. Characteristics of metal flow in a hearth have been analysed by using the numerical calculation, as well as, model experiments.
Equal velocity lines in an uniformly packed hearth are formed on vertical cyrindrical surfaces of which central axis coincides with the position of a tap hole. The flow velocity at a center of hearth is about 0.1cm/s. If a coke free space is formed at the bottom of hearth, flow pattern varies remarkably. The flow velocity in a coke free space of 10cm thickness is more than 10 times of the velocity for uniform bed, and more than 50% of hot metal is drained through it. The velocity in the space decreases remarkably with the increase of the depth of the space The velocity in a space of 40 cm deep is reduced to the same level as that for the uniform flow.
