Mathematical Investigation of Fluid Flow, Mass Transfer, and Slag-steel Interfacial Behavior in Gas-stirred Ladles

Abstract

In this study, the Euler-Euler and Euler-Lagrange modeling approaches were applied to simulate the multiphase flow in the water model and gas-stirred ladle systems. Detailed comparisons of the computational and experimental results were performed to establish which approach is more accurate for predicting the gas-liquid multiphase flow phenomena. It was demonstrated that the Euler-Lagrange approach is more accurate than the Euler-Euler approach. The Euler-Lagrange approach was applied to study the effects of the free surface setup, injected bubble size, gas flow rate, and slag layer thickness on the slag-steel interaction and mass transfer behavior. Detailed discussions on the flat/non-flat free surface assumption were provided. Significant inaccuracies in the prediction of the surface fluid flow characteristics were found when the flat free surface was assumed. The variations in the main controlling parameters (bubble size, gas flow rate, and slag layer thickness) and their potential impact on the multiphase fluid flow and mass transfer characteristics (turbulent intensity, mass transfer rate, slag-steel interfacial area, flow patterns, etc.,) in gas-stirred ladles were quantitatively determined to ensure the proper increase in the ladle refining efficiency. It was revealed that by injecting finer bubbles as well as by properly increasing the gas flow rate and the slag layer thickness, the ladle refining efficiency can be enhanced significantly.

Physical and CFD Modeling of the Effect of Top Layer Properties on the Formation of Open‐Eye in Gas‐Stirred Ladles With Single and Dual‐Plugs

“…Qing et al [30][31][32] X Fluid flow, mass transfer, slag-steel interfacial behavior and mixing time. 18 Liu et al [33] X Fluid flow analysis, axial velocity and turbulent kinetic distribution.…”

“…The open-eye area would increase quickly when slay layer thickness decreases and vice-versa, although the increment is not linear. Qing et al [30][31][32] investigated the fluid flow, mass transfer, slag-steel interfacial behavior and mixing time in industrial gas stirred ladle. Liu et al [33] investigated the effect of various forces, bubble sizes and bubble injection frequencies on the flow analysis in the gas-stirred ladle.…”

Numerical Modeling of Open-Eye Formation and Mixing Time in Argon Stirred Industrial Ladle

“…The finite volume equation of the VOF model can be written in the following form: m qp represent the mass transfer from phase p to q and phase q to p in unit time and volume, respectively; α q is the volume fraction of phase q; ρ q is the density of phase q; and S α q is the source term taken as 0 in Fluent software. The volume fraction of main phase is not calculated in Fluent software, while it can be acquired by Equation (4). When the volume fractions are summed, the following equation is satisfied:…”

“…Cao et al [4] studied the fluid flow, mass transfer, and open-eye behavior in an industrial scale ladle using both volume of fluid (VOF) and Euler-Lagrange modeling approaches. Cao et al [5] extended the work to investigate the mixing phenomenon using a species transport model.…”

Physical Modeling Evaluation on Refining Effects of Ladle with Different Purging Plug Designs

“…Intense interactions occur between the slag and molten steel because the overlying slag is pushed to the side . It is widely known that the bubble size and its motion affect momentum, heat, and mass transfer in gas–liquid bubble flow . In addition, finer bubbles have a high probability for inclusions attachment due to their larger gas/liquid interfacial area, which is determinant to the quality of steel .…”