Computational fluid dynamics (CFD) simulation of effect of baffles on separation in mixer settler

The main ideas in the development of the solvent extraction mixer settler focused on achieving clean phase separation, minimizing the loss of the reagents and decreasing the surface area of the settlers. The role of baffles in a mechanically agitated vessel is to ensure even distribution, reduce settler turbulence, promote the stability of power drawn by the impeller and to prevent swirling and vortexing of liquid, thus, greatly improving the mixing of liquid. The insertion of the appropriate number of baffles clearly improves the extent of liquid mixing. However, excessive baffling would interrupt liquid mixing and lengthen the mixing time. Computational fluid dynamics (CFD) provides a tool for determining detailed information on fluid flow (hydrodynamics) which is necessary for modeling subprocesses in mixer settler. A total of 54 final CFD runs were carried out representing different combinations of variables like number of baffles, density and impeller speed. CFD data shows that amount of separation increases with increasing baffles number and decreasing impeller speed.