Affiliation:
1. División of Process Simulation K&E Technologies Manizales 88, Col. San Pedro-Zacatenco Mexico City 07369 Mexico
2. Department of Metallurgy and Materials Engineering Instituto Politécnico Nacional-ESIQIE Ed. 7 UPALM, Col. Zacatenco Mexico City 07738 Mexico
3. Metallurgy Graduate Center Instituto Tecnológico de Morelia Av. Tecnologico No.1500 Morelia Mich. C.P.58120 Mexico
Abstract
A slab caster with a wide casting mix carries high‐frequency steel grade changes using a small, 14 ton capacity tundish and needs to decrease the intermixed steel tonnage. Testing different tundish arrangements, through a water one‐third scale model, permits a flow control design to decrease the amount of mixed steel. A computer fluid dynamics approach, based on the Realizable k–ε model, replicates the experimental results. It helps to elucidate the role of the tundish filling rate, finding that increasing it increases the dissipation rate of kinetic energy coming out from the turbulence inhibitor. At high filling rates, the degraded kinetic energy of the downstream flow drives the residues of the “old” steel, prolonging the intermixing phenomena. In its later stages, the intermixing phenomena imply diffusion and transport on small scales, and both are governed by the Schmidt number given by the ratio of the Batchelor and Kolmogorov length scales, according to . The Schmidt, Sc, numbers in steel are in the range of 28–440. These large Sc numbers mean that the diffusion process must reach the dissipative scales of turbulence, that is, beyond Kolmogorov´s scale, to achieve a complete mixing at microscale levels.
Funder
Instituto Politécnico Nacional
Subject
Materials Chemistry,Metals and Alloys,Physical and Theoretical Chemistry,Condensed Matter Physics
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