Hydrodynamicst axial mixing and mass transfer in rotating disk contactors

Correlations for predicting characteristic velocity both above and below the critical rotor speed have been obtained under conditions with and without solute transfer. It has been found that (1) above the critical rotor speed, the characteristic velocity U₀ is proportional to g/D_rN², whereas below this value a transition region exists where U_o is proportional to (g/D_rN²)^0.26; (2) multiple regression analysis of the experimental data of continuous phase axial mixing shows that the axial dispersion coefficient varies not only with the rotor speed and modified velocity of continuous phase but also with the velocity of dispersed phase. With varying RDC operations, the true value of K_od corrected for axial mixing changes continually between the limiting values predicted from stagnant and fully turbulent drop models. However, the highest experimental values were only 30 to 40% of those predicted by the Handlos-Baron model at the same drop Peclet number.