Modeling of heat transfer and refractory wear in the blast furnace hearth using finite element method 

The wear of hearth refractory by hot metal penetration and mechanical erosion are the limiting factors in the life of a blast furnace and their control and minimization result in a direct benefit in an extended campaign. At the same time, it is very difficult to directly estimate the amount and location of hearth erosion during any campaign. Mathematical model is an appropriate tool to quantify the amount of erosion based on the prediction of temperature profile particularly 1150 °c freeze line isotherm in the hearth.

In the present investigation, an axisymmetric conductive heat transfer model based on finite element method has been formulated and a computer software is developed. Using the model and the computer code, temperature profile and hearth wear have been predicted for designated blast furnaces and effect of cooling conditions at the side walls and at the bottom of the hearth has been estimated. Different refractory materials in the hearth are modeled by incorporating appropriate thermal conductivity values as function of temperature for each material. The convective boundary conditions at the side walls and bottom of the hearth are modeled by taking an appropriate convective heat transfer coefficients for each cooling system.