Date of Award

Spring 1965

Document Type

Dissertation

Degree Name

Doctor of Engineering Science in Chemical Engineering

Department

Chemical Engineering

First Advisor

Jerome J. Salamone

Second Advisor

Martin J. Levy

Third Advisor

Deran Hanesian

Fourth Advisor

John E. McCormick

Fifth Advisor

L. Bryce Anderson

Abstract

Experimental batch heat-transfer data were obtained for both Newtonian and pseudoplastic liquids in a baffled agitated vessel. The fluids tested had flow behavior in-dexes between 0.36 and 1.0; and the apparent viscosity ranged from 1 to 1200 centipoise. Four types of impellers (anchor, paddle, propeller, and disk and vane turbine) were studied using eleven separate impellers. The probable error in the measured heat transfer coefficient was ± 20 percent.

The effects of the generalized Reynolds number, generalized Prandtl number, and viscosity ratio were studied. In addition the effect of impeller diameter was studied for paddles, propellers, and turbines; and the effect of impeller width was studied for the paddles and turbines. The vertical height of the impeller above the bottom of the vessel was shown to be a significant variable.

The data for the Newtonian liquids, in general, substantiated presently accepted correlations. For the power law pseudoplastic fluids two correlations were developed. One correlation was based on the dimensional analysis of the equations describing a flow model of the system. The second correlation is based on Metzner's evaluation of the rate of shear in an agitated vessel. The former correlation has five to seven constants which vary with impeller type while the latter has five to seven constants, two of which vary with the impeller type. When the flow behavior index is 1.0 both correlations reduce to the generally accepted correlations for Newtonian liquids. The correlations fit the experimental data with an average error of ± 10 to 14 percent.

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