Study of flow characteristics in a ladle with top lance injection

Two-phase flows in a model ladle agitated by top blowing lance injection are analysed using the CFX code. A Eulerian two-phase approach is used. Predictions show that different flow patterns exist with changing operational conditions (Q, dn, and hn/H). The gas-liquid plume spreads radially, gradually in most of the plume region and extensively near the free surface. For the cases considered, bubbles in the central plume accelerate up to their terminal rising velocity, then move at this rising velocity, and thereafter decelerate when they approach the free surface. A similar behaviour is demonstrated for the liquid rising velocity. The effect of the drag and lift force coefficients on flows are also examined. A large lift coefficient (CL> 0.15) should be utilised, and the drag coefficient for spherical cap shaped bubbles is preferred. Numerical results are compared with available experimental data, and an excellent agreement is achieved outside the gas-liquid plume, though a relatively large deviation is observed within the plume.