FLUID-DYNAMICS OF SUSPENSION

Fluid dynamics of suspension. Data of primary interest associated with the use of suspension stirrers are the operating conditions required to suspend the particles of solids and to distribute them in the desired manner throughout the liquid. The tendency to undergo phase separation plays a decisive role in this connection. It has proved convenient in describing the material properties of the suspension to consider the sedimentation properties of the particles in the unperturbed liquid. The question of a scale‐up rule for transferring the suspension state examined in an experimental stirrer to a large scale set‐up has come in for much discussion. The data reported in the literature for the performance per unit volume lie in the range P/V ∼ d0.5, corresponding to the scale‐up rule Fr* = const., and P/V ∼ d−1, corresponding to a constant circumferential velocity wu = const. On the basis of results reported in this paper the recommended scale‐up rule is P/V ∼ d−0.33. Copyright © 1979 Verlag Chemie, GmbH