Temperature control of liquid steel by plasma heating is physically and mathematically modeled. A dimensionless plasma heating number is employed for scaling-up of heating operations between a steam jet for water model and a plasma prototype. Overall responses of step input temperatures in steel are fairly well predicted by the physical model. Fluid flow structure and thermal fields, in terms of dimensionless temperatures, of steel are different to those of water. Two positions of plasma in a tundish were studied, centered and off-centered. The second position decreases the heating efficiency of a plasma, although, a more homogenous thermal field is obtained in regard to the first position. Consequently, a centered position offers a faster thermal response than the off-centered one. Flow controllers decrease also the heating efficiency of plasma heating due to the formation of stagnant zones, located in their proximities, which are not active enough to exchange momentum and heat with the bulk flow.
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