Most of them deal with the cases when the liquid phase is a
Newtonian fluid with low viscosities. From various sets of experiments
carried out atlab-scale and/or atlarger scale, some empirical
correlations for kla are proposed, involving either dimensional or
dimensionless parameters. At present, the most frequently used
dimensional correlation remains the one of Van’t Riet [6] or some
variants in which the constant and exponents have been modified.
They are expressed such as