Publication Date:
2017-12-16
Description:
A detailed hydrodynamic characterization in the transitional flow regime (20≤ Re ≤133) of two variants of the Norstone Polyblade® high-shear impeller (HSI), of industrial relevance, is presented. The study was carried out on a simulated Newtonian fluid using computational fluid dynamics (CFD). Measurements of power number were carried out in order to validate the simulation results. Hydrodynamic parameters considered of key importance in powder dispersion processes ( i.e. viscous dissipation and effective circulation), were used to assess the impellers’ performance. Furthermore, their performances were compared with reported data for two ring-style HSIs of two and four rings, and power number measurements of a sawtooth (Cowles type) impeller. The results show that both NR-type and Cowles impellers exhibit lower power number values, i.e. , they consume less power at a given Reynolds number than the two ring-style HSIs. In addition, it was found that at the same power input, the Norstone impellers induce higher maximum values of viscous dissipation than the two ring-style HSIs and suitable effective circulation, what in principle, makes them better suited for mixing dispersion processes.
Print ISSN:
0930-7516
Electronic ISSN:
1521-4125
Topics:
Chemistry and Pharmacology
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Process Engineering, Biotechnology, Nutrition Technology
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