Collect. Czech. Chem. Commun. 1984, 49, 2875-2890

Transport characteristics of a mechanically agitated aerated vessel

Oldřich Holeček, Václav Linek, František Hovorka and Petr Beneš

Department of Chemical Engineering, Prague Institute of Chemical Technology, 166 28 Prague 6


The gas holdup and impeller power input in a mechanically agitated aerated vessel were measured for aqueous solutions of ten inorganic salts as functions of the type and concentration of the electrolyte present, the impeller speed, and the gas flow rate. The dependence of the holdup on the physical properties of batch is best described by relations including the quantity X = c(dσ/dc)2F, where F = (1 + d ln f/d ln c)-1. The best fit to experimental holdup data is given by the empirical equation Z = 5.0 . 10-4 Re-0.226 Kp0.25 We1.09 Y1.16, where Kp = Vg/nd3, Y = 2 - exp (-X+), X+ = X/Xcrit, Xcrit = 3. 10-6 k mol-1 kg2 m3 s-4, with mean and maximum deviations between calculated and experimental values of 12% and 20%, respectively. Incorporation of quantities that improve the ability of holdup correlations to account for the dependence of gas holdup on the physical properties of electrolyte solutions fails to produce the same effect in correlations for impeller power input to aerated batch. The best estimate of the power input (within 20%) is obtained by using the equation PaPo = 0.226 We-0.0081 Kp-0.294.