Cavern Sizes Generated in Highly Shear Thinning Viscous Fluids by SCABA 3SHP1 Impellers

• Published in: Food and bioproducts processing Vol. 75; no. 4; pp. 232 - 238
• Main Authors: Amanullah, A., Hjorth, S.A., Nienow, A.W.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-1997
• Subjects: cavern; impeller retrofitting; mixing; power law fluids; power measurement; SCABA 3SHP1 impellers; impeller retrofitting; cavern; mixing; power law fluids; power measurement; SCABA 3SHP1 impellers
• ISSN: 0960-3085; 1744-3571
• DOI: 10.1205/096030897531630

The dimensions of caverns formed in highly shear thinning Carbopol solutions using axial flow SCABA 3SHP1 impellers with
D/T ratios of 0.33, 0.44 and 0.49 at varying clearances from the vessel base, have been measured visually and compared to those from a standard Rushton turbine. Unaerated power data with these axial flow impellers in 0.1 and 0.2% Carbopol are also presented. It is shown that increased impeller clearance from the vessel base is beneficial in generating larger cavern volumes for a given power input. In addition, a standard Rushton turbine can be retrofitted with a larger diameter, low power number SCABA 3SHP1 impeller for equal speed, torque and power whilst providing significantly increased cavern volumes. The bulk mixing performance can be further enhanced if the optimum clearance ratio is selected for the SCABA 3SHP1 impeller. The results of this study can be applied for selecting suitable impeller geometries and operating parameters for effective mixing of highly shear thinning, viscous fluids.