1996 Volume 36 Issue 5 Pages 493-502
An examination was made in regard to the influences of various factors on descent characteristic at a free surface and inner burden based on the model experiment and measurements at an actual furnace. At the same time a non-uniform descent model was prepared and a study was conducted with the use of a non-uniform descent model as to a mechanism forming the radial distribution of burden descent velocity near the burden surface in a blast furnace. As a result, the following knowledge has been acquired. The relative burden descent velocity at the free surface is relatively larger at the peripheral area and smaller at the central area than that at the inner burden. The relative burden descent velocity at the peripheral area on the free surface is large when a peripheral ore/coke is high or there is a wall erosion at the upper part of shaft. Non-uniform descent characteristic at the free surface is remarkable for alumina ball and sintered ore having a small repose angle and not remarkable for coke having a large repose angle. In the actual operation, radial distribution of relative burden descent velocity near the burden surface greatly varies depending on a relative ore/coke distribution, difference in particle size between coke and sintered ore and physical property values, even if the charging pattern is the same.
