Power requirements and blend times in the agitation of pseudoplastic fluids

Agitation and blending studies were made with solutions of Natrosol 250H, which were pseudoplastic fluids with nonconstant flow‐behavior indexes. The published power number‐Reynolds number correlation for pseudoplastic fluids having constant flow‐behavior indexes is valid for Natrosol solutions. Published correlations for blend times in Newtonian fluids do not apply to Natrosol solutions; the blend times are ten to fifty times longer than with Newtonian fluids of the same apparent viscosity. Blend times are shortest in unbaffled vessels when a vortex is formed and correlate well with the vortex depths. Insertion of radial baffles always lengthened the blend time.