1982 Volume 68 Issue 15 Pages 2295-2302
In order to clarify the dynamic behavior of the cohesive zone in the blast furnace, a simulation model experiment was carried out.
One-sixth scale sector model unit was built. Quasi are and coke were charged at the top and hot air (180°C) was injected from the tuyeres. The formation process of the cohesive zone was observed via a glass wall fitted on the front of the unit.
(1) The cohesive zone is found to be classified into inverted U, inverted V and normal W types, each of which seems to be attributable to the characteristics of gas flow around the root of the cohesive zone. Among them, inverted V type is most desirable for its efficient heat exchange and low thermal load.
(2) As concerns burden distribution, a high ore/coke ratio in the periphery makes the cohesive zone inverted U type and a low ore/coke ratio results in W type. In order to obtain inverted V type, an appropriate permeability of the root, especially at the wall side, is necessary.
(3) The cohesive zone tends to become inverted U type with a decrease in the thermal flow ratio. An increase in the blast volume raises the level of the cohesive zone and causes its width to become broad. The permeability of the cohesive layers also exerts a large effect on their formation.
The mechanism of the cohesive-zone formation has been discussed.
