Effect of solids loading on agitator just‐suspended speed

Data taken with six solids at numerous Zwietering loadings ranging from near zero to 67 have been used to determine the just‐suspended speed Zwietering loading exponent ( N js  ∝  X n where n is the Zwietering solids loading exponent). When only the loadings range similar to that studied by Zwietering [Zwietering, Chem. Eng. Sci . 1958 , 8 , 244] is considered (0 <  X  < 18), the solids loading exponent averaged over all solids is equal to 0.12, essentially the same as the 0.13 reported by Zwietering. However, when the entire loading range is considered (0 <  X  ≤ 67), a higher average exponent of 0.17 is found and a single power‐law correlation does not accurately describe the experimental data. A piecewise fit of the data indicates that the solids loading exponent increases from an average value of 0.097 at low solids loadings (0 <  X  ≤ 5) to 0.22 at intermediate loadings (5 ≤  X  ≤ 25) and 0.34 for the highest loadings (25 ≤  X  ≤ 67).