Bruno Blais, Olivier Bertrand, Louis Fradette
et François Bertrand
Article de revue (2017)
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Libre accès au plein texte de ce document Version finale avant publication Conditions d'utilisation: Creative Commons: Attribution-Pas d'utilisation commerciale-Pas de modification (CC BY-NC-ND) Télécharger (1MB) |
Abstract
Solid–liquid mixing as a unit operation still faces considerable challenges, notably regarding the prediction of the impeller speed required to suspend the particles (Njs), the fraction of suspended solids and the homogeneity of the suspension at a given speed. In this work, we extend to the turbulent regime, by means of large eddy simulation (LES), a CFD-DEM model developed recently in our group for solid–liquid mixing. The resulting model is used to study the mixing of glass particles in a baffled stirred tank equipped with a down-pumping pitched blade turbine. Various characteristics of the liquid dynamics as well as the distribution and motion of the solids are investigated. The fraction of suspended solid particles predicted by the model is validated against experimental data obtained via the pressure gauge technique (PGT). Two new methods to calculate the fraction of suspended particles in a Euler–Lagrange simulation, the so-called Lagrangian suspended fraction analysis (LSFA) and the decorrelated fraction analysis (DFA) techniques are introduced. The results obtained with these two methods, as well as with many others taken from the literature, are compared to the Zwietering correlation and to the results obtained by the PGT. It is found that some techniques proposed in the literature, namely the local concentration, the power consumption and the transient solids concentration analysis techniques, cannot be applied adequately in this case. On the other hand, the LSFA, DFA and PGT techniques are observed to predict accurately the fraction of suspended solids when compared to experimental PGT data.
Mots clés
Multiphase flow; Solid–liquid mixing; Large-eddy simulation; DEMCFD-DEM
Sujet(s): | 1800 Génie chimique > 1800 Génie chimique |
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Département: | Département de génie chimique |
Centre de recherche: | URPEI - Unité de recherche en procédés d'écoulements industriels |
Organismes subventionnaires: | CRSNG/NSERC, CRSNG/NSERC - Vanier Scholarship |
URL de PolyPublie: | https://publications.polymtl.ca/9067/ |
Titre de la revue: | Chemical Engineering Research and Design (vol. 123) |
Maison d'édition: | Elsevier |
DOI: | 10.1016/j.cherd.2017.05.021 |
URL officielle: | https://doi.org/10.1016/j.cherd.2017.05.021 |
Date du dépôt: | 12 août 2021 14:05 |
Dernière modification: | 05 avr. 2024 11:15 |
Citer en APA 7: | Blais, B., Bertrand, O., Fradette, L., & Bertrand, F. (2017). CFD-DEM simulations of early turbulent solid–liquid mixing: Prediction of suspension curve and just-suspended speed. Chemical Engineering Research and Design, 123, 388-406. https://doi.org/10.1016/j.cherd.2017.05.021 |
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