The design and controI of mixer-settler batteries is very important for the technical and economical viability of the industrial processes of liquid-liquid extraction. Direct experimentation with these equipments is not always feasible due to their complexity and costs. Computer simulation allows predicting the behavior and optimizing the design of these types of equipments reducing the costs.
In this work we develop a dynamical model for the settler unit of a liquid-liquid system, able to describe the transient state, including hydrodynamic phenomena of drop-drop and drop-interface coalescence and eventually the mass transfer phenomena for the shallow layer settler.
Starting from a steady-state model developed by Ruiz for the settler, we developed a sequential algorithm able to simulate also the transient state of a mixer-settler system. Given the non-linear character of the problem, the adopted strategy was essentially numerical.
The algorithm developed was able to simulate the band thickness for the transient state. On the other hand, the results obtained with this algorithm when the steady-state is reached are in agreement with the results previously published for the steady-state.
During this work we detected possible conceptual limitations of this algorithm introduced by the model of the steady-state. To overcome these problems, we have proposed a new dynamic model using a kinetic formulation in which the movement of the dispersion is modelled as caused by gravity.