CFD simulation of solid–liquid stirred tanks for low to dense solid loading systems--颗粒学报PARTICUOLOGY

Wadnerkar, D., Tade, M. O., Pareek, V. K., & Utikar, R. P. (2016). CFD simulation of solid–liquid stirred tanks for low to dense solid loading systems. Particuology, 29, 16-33. https://doi.org/10.1016/j.partic.2016.01.012

CFD simulation of solid–liquid stirred tanks for low to dense solid loading systems

Divyamaan Wadnerkar, Moses O. Tade, Vishnu K. Pareek, Ranjeet P. Utikar ^*

Department of Chemical Engineering, Curtin University, Perth, WA 6102, Australia

10.1016/j.partic.2016.01.012

Volume 29, December 2016, Pages 16-33

Received 6 March 2015, Revised 30 November 2015, Accepted 27 January 2016, Available online 30 May 2016, Version of Record 18 November 2016.

E-mail: r.utikar@curtin.edu.au

Highlights

• Stirred tanks with solid loadings up to 40 wt% were simulated using CFD.

• Euler–Euler with KTGF approach provided accurate results for simulating solid suspension.

• Syamlal–O'Brien drag model was found to be applicable over a wide range of conditions.

• Turbulent dispersion force contributed marginally in improving the prediction.

• Reynolds stress model captured the anisotropic turbulence prevalent in the system.

Abstract

The hydrodynamics of suspension of solids in liquids are critical to the design and performance of stirred tanks as mixing systems. Modelling a multiphase stirred tank at a high solids concentration is complex owing to particle–particle and particle–wall interactions which are generally neglected at low concentrations. Most models do not consider such interactions and deviate significantly from experimental data. Furthermore, drag force, turbulence and turbulent dispersion play a crucial role and need to be precisely known in predicting local hydrodynamics. Therefore, critical factors such as the modelling approach, drag, dispersion, coefficient of restitution and turbulence are examined and discussed exhaustively in this paper. The Euler–Euler approach with kinetic theory of granular flow, Syamlal–O'Brien drag model and Reynolds stress turbulence model provide realistic predictions for such systems. The contribution of the turbulent dispersion force in improving the prediction is marginal but cannot be neglected at low solids volume fractions. Inferences drawn from the study and the finalised models will be instrumental in accurately simulating the solids suspension in stirred tanks for a wide range of conditions. These models can be used in simulations to obtain precise results needed for an in-depth understanding of hydrodynamics in stirred tanks.

Graphical abstract

Keywords

Solid–liquid stirred tanks; Computational fluid dynamics; Simulation approach; Drag model; Turbulence model

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