2001 Volume 87 Issue 5 Pages 380-387
Stable operation of the blast furnace much owes to satisfactory heat maintenance 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, and direct reduction of slag (FeO), (3) handling gas, solid, and especially metal and slag separately with respect to accurate analysis of liquid behavior.
By the estimation of effects of various operational conditions on the temperature in lower part of the blast furnace, the following results have been obtained.
(i) Change of slag (FeO) at cohesive zone makes much influence on temperature in the lower part. To keep stable operation, less than 20 wt% of slag (FeO) at cohesive zone is required.
(ii) The factors keeping coke temperature at center of deadman are (1) decreasing of slag (FeO) at cohesive zone, (2) decreasing of void fraction of deadman, (3) increasing of temperature of cohesive zone, (4) increasing of temperature of raceway gas, and (5) decreaseng of O/C at center. And the factors keeping coke temperature under raceway are (1) decreasing of slag (FeO) at cohesive zone, (2) increasing of diameter of deadman coke, (3) increasing of void fraction of deadman, (4) increasing of temperature of cohesive zone, (5) increasing of temperature of raceway gas.
