Physical modelling of tundish plasma heating and its mathematical interpretation

Steel flow and heat transfer in tundishes heated by plasma is physically modeled using a water model with tracer injections and the experimental results are interpreted through a turbulent k-ε mathematical model. The thermal modeling was carried out using step temperature inputs to decrease by 7 K the initial water temperature followed by a heating stage by a steam jet that simulates the plasma heating process of liquid steel in the tundish. To make valid the scaling operation of the plasma heating from the steam jet experiments a dimensionless plasma heating number was derived. The thermal response of the cooling-heating cycles was well predicted by a double dispersion coefficient model. On the other hand, the mathematical model indicates that the steam jet acts as a brake of the velocity for the liquid volume just under its direct contact lossing momentum. This loss of momentum is compensated by slight increases of the liquid velocities in the liquid volumes that are out the direct action of the steam jet.