described in , was used to calculate these reference time-scales (T). In eq 4, is the vessel's diameter (L) and the turbulent power number assumed to have a value of 5.8 common to Rushton turbines . The reference vessel's stirrer speed was adjusted to yield a similar power input as in the simulated tank by assuming that multi-impeller power equals single impeller power multiplied by the number of impellers, i , while keeping the ratio of impeller and tank diameters the same. Under these assumptions, eq 4 led to the expression