INFLUENCE OF ORE TO COKE RATIO DISTRIBUTION ON DESCENDING AND MELTING BEHAVIOR OF BURDEN IN THE BLAST-FURNACE

The influence of ore/coke distribution on the descending and melting behaviors of burden was analyzed by using a three-dimensional semicircular warm model of the blast furnace under conditions set as similar as possible to the physical phenomena in the furnace. If the ore/coke in wall region is locally increased, the descending velocity increases and the gas flow velocity decreases in that region. An increase of + 0.1 in the heat-flow ratio in the wall region of bosh results in a decrease of about 5-degrees-C (80-degrees-C in the value converted into that of the actual blast furnace based on the Stanton number) in the wall temperature of bosh. At the all coke operation, as the wall temperature in the lower part of the furnace tends to decrease, the ore/coke near the wall should be preferably decreased by the charging of ore closer to the furnace center. At the high-rate coal injection operation, as the melting capacity near the wall is large, the ore/coke in the wall region should be preferably increased and the ore/coke in the center region should be preferably decreased by the charging of ore farther from the furnace center.