The effect of slag properties (thickness and viscosity), have been evaluated in terms of mixing time, exposed surface or ladle eye and energy dissipation. A nozzle configuration defined in terms of the number of nozzles, its radial position and gas flow rate has been employed to describe the influence of the top layer on mixing phenomena. It has been found a negative effect of both slag thickness and slag viscosity on mixing time, on the other hand, the same properties are useful to decrease the exposed surface or ladle eye.An empirical approach using water modeling is suggested to evaluate the average velocity of the bulk liquid. The method was used to define the fraction of stirring energy consumed by the top layer. The result is in agreement with a previous investigation.

No abstract

No abstract

A mathematical model was developed to describe the hydrodynamics of a batch reactor for aluminum degassing utilizing the rotor-injector technique. The mathematical model uses the Eulerian algorithm to represent the two-phase system including the simulation of vortex formation at the free surface, and the use of the RNG k-ε model to account for the turbulence in the system. The model was employed to test the performances of three different impeller designs, two of which are available commercially, while the third one is a new design proposed in previous work. The model simulates the hydrodynamics and consequently helps to explain and connect the performances in terms of degassing kinetics and gas consumption found in physical modeling previously reported. Therefore, the model simulates a water physical model. The model reveals that the new impeller design distributes the bubbles more uniformly throughout the ladle, and exhibits a better-agitated bath, since the transfer of momentum to the fluids is better. Gas is evenly distributed with this design because both phases, gas and liquid, are dragged to the bottom of the ladle as a result of the higher pumping effect in comparison to the commercial designs.

No abstract