Title

Effect of Liquid Level and Agitator Pumping Direction on Turbulent Blend Times

Document Type

Article

Publication Date

4-2014

Publication Source

Canadian Journal of Chemical Engineering

Abstract

With the impeller placed low in the tank (C/T = 1/3), turbulent blend times produced by radial-flow and down-pumping axial-flow impellers generally increase slowly with increasing liquid level in shorter batches (Z/T < 1), but increase dramatically in taller batches (Z/T > 1). The turbulent blend times produced by up-pumping axial-flow impellers increase slowly with increasing liquid level across the entire spectrum of liquid levels that were studied (up to Z/T = 1.75). This can lead to down-pumping blend times that are twice as long as those with up-pumping operation. These differences can be explained by differences in the velocity field in the agitated vessel. Further, the down-pumping mode can produce blend times in tall tanks that are comparable to those of the up-pumping mode if the down-pumping impeller is placed high in the batch such that its discharge flow is directed into the bulk of the liquid.

Inclusive pages

643–647

ISBN/ISSN

0008-4034

Publisher

John Wiley & Sons

Volume

92

Issue

4

Peer Reviewed

yes