The influence of impellers and baffles on the mixing of gas-liquid floating
particles in agitated vessels was investigated. Fifty-two kinds of impelle
r combinations and twelve types of baffle arrangements were used. The assoc
iated power, gas holdup and solids concentration at the vessel bottom were
measured. It is concluded that the mixing characteristics of three-stage im
pellers were superior to those of two-stage impellers for aspect ratios lar
ger than 1.6. The optimal combination of impellers and baffles was proposed
. The correlations of the relative power and the gas holdup for the optimal
combination of impellers under all types of baffles were obtained.