| Abstract: | Flow patterns and velocity profiles have been studied in anchor agitated vessels. The flow paths around the mixer blade in a Newtonian fluid may be characterized satisfactorily in terms of the blade tip Reynolds number and the blade width/wall clearance ratio. Calculations of the dispersion produced by the blade within a horizontal plane are not in agreement with experimentally determined (and therefore three-dimensional) mixing times. This suggests that the vertical secondary flow is the more important mixing mechanism. Such vertical flows are shown to be more pronounced in visco-elastic systems and the horizontal plane velocity profiles are substantially modified. A mechanism is suggested for this. |
