Multiphysics Numerical Simulation Model and Hydraulic Model Experiments in the Argon-Stirred Ladle

The argon-stirred ladle is a standard piece of steelmaking refining equipment. The molten steel quality will improve when a good argon-stirred process is applied. In this paper, a Multiphysics model that contained fluid flow, bubble transport, alloy transport, bubble heat flux, alloy heat flux, alloy melting, and an alloy concentration species transport model was established. The fluid model and bubble transport model that were used to calculate the fluid velocity were verified by the hydraulic model of the ladle that was combined with particle image velocimetry measurement results. The numerical simulation results of the temperature fields and steel-slag interface shape were verified by a ladle that contained 25 t of molten steel in a steel plant. The velocity difference between the hydraulic model and numerical model decreased when the C-L (integral time-scale constant) increased from 0 to 0.3; then, the difference increased when the C-L increased from 0.3 to 0.45. The results showed that a C-L of 0.3 approached the experiment results more. The bubble heat flux model was examined by the industrial practice, and the temperature decrease rate was 0.0144 K/s. The simulation results of the temperature decrease rate increased when the initial bubble temperature decreased. When the initial bubble temperature was 800 degrees C, the numerical simulation results showed that the temperature decrease rate was 0.0147 K/s, and the initial bubble temperature set at 800 degrees C was more appropriate. The average melting time of the alloy was 12.49 s and 12.71 s, and the mixture time was approximately the same when the alloy was added to two slag eyes individually. The alloy concentration had fewer changes after the alloy was added in the ladle after 100 s.

Automated summary

A comprehensive multiphysics model was established to study the effects of fluid flow, bubble transport, and alloy transport processes on the molten steel quality in an argon-stirred ladle. The numerical simulations and experimental verifications provided insights into the optimal integral time-scale constant and initial bubble temperature for improved steel quality. The results also showed the minimal changes in alloy concentration after alloy addition in the ladle.