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Gas-induced liquid-phase mixing in shallow vessels is important to primary and secondary steel-refining processes and governs the quality of the steel. In the present work, we have investigated the dynamics of meandering bubble plumes and their role in liquid-phase mixing in shallow vessel that corresponds to 1:6 scaled-down model of ladle used in the secondary steel-refining process. The effects of multiple meandering bubble plumes and their interactions on the liquid-phase velocity distribution, recirculatory flow, plume oscillation frequencies, and turbulent kinetic energy are analyzed for different bottom injection configurations using particle image velocimetry measurements. The role of meandering bubble plumes and their interactions in the liquid-phase mixing is analyzed using planar laser-induced fluorescence measurements. ~60% reduction in the mixing time was found with differential flow scheme. Present findings help to understand the contributions of differential flow and bubble plumes interactions to liquid-phase mixing in shallow vessels.

The present work is carried out to understand the effect of free surface on liquid velocity distribution, dynamics and liquid phase mixing in a shallow basic oxygen furnace (BOF). Three‐dimensional/transient Euler–Lagrange (EL) without/with volume‐of‐fluid (VOF) simulations of dispersed gas–liquid flow in a scaled‐down model of the BOF were performed. For lower H/D ratios, EL simulations performed with no‐slip and free‐slip boundary conditions led to oscillatory plume behavior and higher liquid velocity regions which in turn led to lower mixing time. In contrast, EL + VOF simulations led to reduced meandering motion of bubble plumes and lower liquid velocities resulting in higher mixing times. Interestingly, the mixing time predicted using EL + VOF approach was found to be in a good agreement with the measurements. The results presented in this work show that free surface has a significant effect on dynamics of gas–liquid flow and liquid phase mixing for shallow vessels with H/D ≤ 0.5. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3582–3598, 2017