Application of computational fluid dynamics in the development and improvement of steelmaking processes

Abstract

VOEST‐ALPINE Industrieanlagenbau (VAI) and VOEST‐ALPINE Stahl Linz (VASL), in cooperation with the University of Linz, apply CFD in the field of steelmaking with the motivation to make processes more cost efficient and environmentally compatible, as well as to achieve products of excellent quality. The understanding of existing processes can be substantially improved by numerically simulating fluid flows. This is of special importance for liquid steel flows, which can hardly be observed or investigated by measuring instruments due to the rough ambient circumstances. Simulation of the secondary fume control of electric arc furnaces while taking into account a 3‐dimensional turbulent thermal plume for a 2‐phase flow is performed using k‐ε‐turbulence models flow and an Euler‐Lagrange approach for the particle transport. The results include an optimized air flow design at the inlet of the building and at the outlet through the roof as well as minimized blowing power. The modeling of the steel flow in converters including bottom and side blowing using an Euler‐Lagrange formulation for the calculation of the two‐phase flow and a suited surface model for the iron‐slag‐gas interface. Optimized nozzle configurations and thus shorter process times are achieved.

The Determination of the Minimum and Operational Gas Flow Rates for Sidewall Blowing in the AOD-Converter

“…8. It shows that the flow patterns in the all cases with tuyere of 3 mm diameter are analogous with the earlier studies 6,[10][11][12][13]17) (Fig. 8(A) and Fig.…”

“…Delay time was defined as a time which fluid flow takes to transfer from an electrode to other. The hypothetic flow patterns in the model are based on the previous studies 6, [10][11][12][13]17) including two mixing zones.…”

“…Hoefele and Brimacombe 16) found out also that the penetration of the jet increases with the modified Froude number (N Fr ) and the density ratio (r g /r l ) as Themelis's 14) equation predicts. According to the previous studies, 6,[10][11][12][13]17) the sidewall blowing in AOD generates two asymmetric mixing zones: a smaller mixing zone near the sidewall with tuyeres and the larger main mixing zone away from it. The position of the recirculation flow moves farther from the tuyeres with increased intensity of sidewall blowing.…”

“…6,13) Themelis et al 14) derived well-known equation for the jet trajectory in the liquid bath. Igwe et al 15) and Hoefele and Brimacombe 16) made semi-empirical correlations for the penetration of the gas jet with the submerged gas injection.…”

Physical and Mathematical Modeling of Multiphase Flows in a Converter

“…B. K. Li 37) proposed a method to predict three-dimensional flow in bottom gas stirred baths. Thereafter, significant progress has been made toward a full simulation [38][39][40][41][42][43][44][45][46][47][48] due to the decreasing computational costs and increasing power of commercial modeling packages, which can help us achieve wonderful insights into flow related phenomena without inherent inaccuracies in water model experiments. A comprehensive understanding of the highly coupled phenomena occurring in a converter can be obtained through all these developments of computational fluid dynamics simulations with high fidelity.…”