1992 Volume 78 Issue 7 Pages 1171-1178
Heat transfer behavior and the state of the coke packing zone in the blast furnace hearth were investigated by laboratory experiment and plant data analyses. It was found that the heat transfer coefficient between the flowing molten iron and brick surface is too large to form solidification layer of molten iron at the brick surface; hence, a zone of low permeability against the molten iron and slag flow was expected to exist in the hearth when the brick temperature is low. The concept of the low permeability zone has enabled us to interpret such phenomena observed in operation as (1) the periodical temperature changes of the bottom bricks, (2) differences in the metal and slag conditions at respective tap holes, (3) and the correlation between the flow-out index of slag and the bottom brick temperature.
