Numerical simulation of liquid steel flow in wedge-type one-strand slab tundish with a subflux turbulence controller and an argon injection system

Abstract

The paper presents computational modelling of the liquid steel flow in a wedge-type one-strand slab tundish. The modelling was extended on the variance of liquid flow under a subflux turbulence controller (STC) and a gas permeable barrier on the tundish bottom. Commercial software was used for solving the mathematical model of the casting process. For the description of interactions between the continuous phase (liquid steel) and the discrete phase (inert gas), an Euler-Lagrange description was chosen. The internal space of the subflux turbulence controller had the shape of a truncated cone, made according to a new design. Three locations for the gas permeable barrier were simulated and the flow rate of inert gas blown into the liquid steel was varied in the range from 10 to 30 Nl/min. The numerical modelling was validated by experimental tests which were carried out in an industrial wedge-type tundish of a Polish steel plant. The industrial experiments included a direct sequence of heats of different chemical analysis in the course of the casting operation. The computations provided liquid steel flow maps, residence time distribution curves (RTD), and the volumes of particular flow types (stagnant, plug and ideal mixing flows), which characterize the effect of argon blowing and the subflux turbulence controller on liquid steel flow in the tundish. As a result, the industrial tundish operation was optimized. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.