Dispersion coefficient and settling velocity of the solids in agitated slurry reactors stirred with multiple rushton turbines

The feature of solids distribution in tanks stirred with multiple Rushton turbines was investigated. Both transient and steady-state experiments were performed in tanks of two scales with a variety of suspensions. The data were analysed with the axial sedimentation- dispersion model. The axial dispersion coefficient of the solid phase was found not to differ from that of the liquid by more than 20%. The effective particle settling velocity in the stirred medium was then determined. It is confirmed that this parameter is different from the terminal settling velocity. Their ratio exhibits the same dependence on Kolmogoroff microscale and particle size as obtained previously with an indirect, approximate approach. © 2002 Elsevier Science Ltd. All rights reserved.