A Mathematical Model of Blast Furnace Based on the Assumption of Uniform Distribution of Burdens and Gas

Abstract

A new mathematical model of the blast furnace has been developed for estimating the effect of the coke reactivity on the operational results of the experimental blast furnace in Institute of Industrial Science, University of Tokyo.
The furnace volume above the tuyere level is divided into three regions, namely, “indirect reduction”, “direct reduction” and “meltscontaining” by two isotherms, and the temperatures of which are considered to be determined by the coke reactivity and by the melting point of metal, The model is made up of the stagedheat balance on the regions and a rate equation of indirect reduction expressing the topochemical progress of two interfaces. Heat of reaction is included in the water equivalent of condensed phases and “heat level” of the furnace is represented by the coke temperature at the tuyere level.
It is estimated from the calculation that coke consumption in the experimental furnace might be reduced by 119kg/t-metal, of which 33 kg/t-metal can be attributed to the reactivity, be the use of petroleum coke differing from metallurgical coke in several properties besides reactivity.
The model can also be applied to the investigation of the effect of natural gas injection on coke rate and replacement ratio in a commercial furnace. The calculated coke rate and CO-utilization coincide well with the operational results.