Unsteady state heat transfer analysis of lower part of blast furnace with liquid flow

Stable operation of the blast furnace much owes to satisfactory heat mainte nance in lower part of it. To make clear heat transfer behavior in lower part of the blast furnace, a new mathematical model has been developed. The feature of the model is (1) treating as unsteady phenomena, (2) considering mass flow, heat transfer, a nd direct reduction of slag (FeO), (3) handling gas, solid and especially m etal and slag separately with respect to accurate analysis of liquid behavi or. By the estimation of effects of various operational conditions on the tempe rature in lower parr of the blast furnace, the following results have been obtained. (i) Change of slag (FeO) at cohesive zone makes much influence on temperatu re in the lower part. To keep stable operation, less than 20 wt% of slag (F eO) at cohesive zone is required. (ii) The factors keeping coke temperature at center of deadman are (1) decr easing of slag (FeO) at cohesive zone, (2) decreasing of void fraction of d eadman, (3) increasing of temperature of cohesive zone, (4) increasing of t emperature of raceway raceway gas, and (5) decreasing of O/C at center. And the factors keeping coke temperature under raceway are (1) decreasing of s lag (FeO) at cohesive zone, (2) increasing of diameter of deadman coke, (3) increasing of void fraction of deadman, (4) increasing of temperature of c ohesive zone, (5) increasing of temperature of raceway gas.