CFD analysis of the turbulent flow in ladles and the alloying process during tapping of steel furnaces

Abstract

Alloying of steel during tapping from BOF and EAF furnaces has recently been studied by computational fluid dynamics (CFD). The original paper has focused on the results of a comprehensive parameter study where alloy type, size, addition time, and other parameters were varied. The present work focuses on the CFD methodology that has been used to simulate the alloying process. In short, the CFD analysis of the dissolution process in the ladle combines a single-phase turbulent flow field computation with the tracking of 1000 stochastic particle paths. In the original paper, the analysis was conducted in 2-dimensional axisymmetric models of the ladle geometries, however, in the present work, the numerical analysis is extended to 3 dimensions. Comparisons are made between results for 3- and 2-dimensional computations. It is shown that the analysis can be conducted in 2 dimensions with only small losses of accuracy. Moreover, it is shown that it is sufficient to obtain statistical averages from 1000 particle tracks. We discuss the simplifying assumptions of the previous work, where we focus on the gas that is entrained by the plunging steel jet. We show simulation results obtained from a CFD methodology that allows the computation of flow fields that include the effect of entrained gas bubbles. Finally, the CFD methodology that is presented and discussed in this work seems to be a useful tool to optimize the alloying process in a steelshop. It can help the steelmaker to decide how, when, and where to add what alloy particles. It also allows estimation of a feeding rate for optimal yield of the alloying particles.