A reasonable tundish flow behavior could improve liquid steel cleanliness by promoting floating and removal of the inclusions. The flow behaviors of the tundish could be obtained by water model experiments and numerical simulations, respectively. However, the difference in density between the tracer and water in the experiment can contribute to notable errors. A new type of tracer, which is a mixture of potassium chloride (KCl) and ethanol, was proposed in this study to reduce the errors. The numerical simulation model was validated by the experimental data and its error was below 2%. By comparing the flow behaviors in seven tundishes with different inner structures obtained by simulation, it is found that the C1 can significantly reduce the dead volume ratio and C4 can improve the uniformity of liquid steel charged though each outlet. The structural strength of the baffle in C1 scheme was not considered, resulting in a crack of the baffle in the industrial trial. Industrial trials of the molten steel flow in the C4-based tundish were conducted and reported a reduction of 43.81% in the inclusions over the prototype.

For a blast furnace, the hearth erosion profile is mainly determined by the temperature distribution in the refractory. Numerical simulation was conducted to simulate the heat transfer and flow in a blast furnace hearth. Based on the simulation results, a fuzzy grey relation analysis method combining the grey entropy analysis and Euclidean grey relation analysis was put forward for evaluating the effects of various factors on the temperature distribution of sample areas at the bottom and sidewall refractory. Impacts of four typical factors (porosity of deadzone, floating height of deadman, radius of deadzone and temperature of cooling water) were evaluated by grey entropy analysis and Euclidean grey relational analysis, respectively. Lastly, a fuzzy grey relational analysis was employed to make a comprehensive evaluation of the four factors. Results have shown that the floating height of deadman is the dominant factor affecting the temperature distribution both on the bottom and sidewall.