Publication Date:
2011-11-26
Description:
A computational fluid dynamics (CFD) model is adopted to simulate the turbulent immiscible liquid-liquid flow in a stirred vessel based on a two-fluid model with a k -ϵ- A P turbulence model. An improved inner-outer iterative procedure is adopted to deal with the impeller rotation in a fully baffled stirred tank. Different drag formulations are examined, and the effect of the droplet size on both the dispersed phase holdup distribution and the velocity field is analyzed. Two different numerical criteria are tested for determining the critical impeller speed for complete dispersion. The simulated critical impeller speeds are generally in good agreement with the correlations in the literature when the fixed droplet size is properly selected. This demonstrates that the modeling approach and the numerical criteria proposed in this work are promising for predicting the dispersion characteristics in liquid-liquid stirred tanks. Two different numerical criteria are proposed for determining the critical impeller speed for complete dispersion in a liquid-liquid stirred reactor. The simulated critical impeller speeds are in good agreement with those from empirical correlations when a fixed droplet size is properly selected. This demonstrates that the presented modeling approach and numerical criteria are promising for predicting the dispersion characteristics of liquid-liquid stirred tanks.
Print ISSN:
0930-7516
Electronic ISSN:
1521-4125
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
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