Development of Operating Model for the Design of Stirrer Arms of Slurries: Empirical Evaluation of Stirrer Arms

Abstract

The “Development of Operating Model for the Design of Stirrer Arms of Slurries: Empirical Evaluation of Stirrer Arms” is reported. Previous work reviewed the “Operating Model for the Design of Stirrer Arms of Slurries” and identified the Two Z and TETE stirrer arms as the most effective. Furthermore, subsequent work “Development of Operating Model for the Design of Stirrer Arms of Slurries: Design and Fabrication of Stirrer Arms” designed and fabricated the Two Z and TETE stirrer arms, evaluated the theoretical (expected) Slurry Mixing Power and Order of Merit Analysis.  The current work did the empirical evaluation of the Two Z and TETE stirrer arms and also the hybrid Two Z - TETE stirrer arms. The Objectives of this research were: to do the mixing performance tests in terms of mixing time, power and energy consumed by the Two Z blade, TETE blade and Two Z – TETE hybrid blade using the constituted slurry; to validate the theoretical (predicted or expected) mixing power for the Two Z blade, TETE blade and Two Z – TETE hybrid blade by comparison with the empirical power using the Chi Square; to do the Power, Time and Energy order of merit analysis for the Two Z blade, TETE blade and the Two Z – TETE hybrid blade. Using the Philips HR 1565 mixer with the Akamu (pap) (Viscosity calibrated) slurries, the time and current drawn for complete and consistent slurry mixing by each type of stirrer arm (namely: Two Z, TETE and Two Z – TETE) was recorded. Results obtained were analyzed using the Chi Square and the Order of Merit. There was excellent agreement between the adjusted predicted (expected) slurry mixing power (E’) and Observed slurry mixing power (O) at 5% confidence level. Empirical model was developed to predict expected slurry mixing power. The Order of Merit analysis revealed the TETE stirrer arm as the most energy efficient.