2022 Volume 62 Issue 4 Pages 677-688
It is essential to understand the relationship between the electromagnetic field and the transport process in a channel type induction heating tundish precisely to improve the quality of the slab. A validated mathematical model was established to investigate the magnetic field characteristics, flow, temperature distribution and the movement of inclusions. In comparison with prior researches, we obtained the effective active zone of the magnetic field by analysing the dimensionless parameters Ha, N and Re. It should contain the channels and the nearby walls connected with the channels. Besides, the electromagnetic force is distributed asymmetrically near the channel outlets, and it is significantly larger within the upper zones of the channel outlets. This leads to the downward flow of the main stream in the distributing chamber, and it also changes the trajectories of the inclusions. When the induction heating is applied, about 75% of the inclusions entering the distribution chamber, regardless of the particle size, will be adsorbed by the tundish covering flux, and about 90% of them will float to the free surface within 120 s. The electromagnetic force can sharply promote the removal of small inclusions (diameter less than 60 µm). The induction heater should not be used intermittently during the casting process because 40%–80% of the inclusions may enter the mold directly during the period of power at 0 kW.
