3-D HYDRODYNAMICS GENERATED IN A STIRRED VESSEL BY A MULTIPLE-PROPELLER SYSTEM

The aim of this study is to optimize the position and the number of pr opellers in a non-standard tall vessel. Laser sheet flow visualization experiments were carried out for selected geometrical arrangements wh ich produced stable flow patterns and good transport between the prope llers. Four double-propeller arrangements corresponding to frequent in dustrial cases and a three-propeller system have been chosen. Comparis on of LDA measurements in the r-z plane, dimensionless global paramete rs N-Qp, Nt(m), N-p, E-p and spatial distribution of local energy diss ipation rate epsilon shows that a three-propeller system is the most e fficient.