CFD modeling of a prismatic spouted bed with two adjustable gas inlets

Abstract

Since the invention of the spouted bed technology by Mathur and Gishler (1955), different kinds of apparatus design were developed and a huge number of applications in nearly all branches of industry have emerged. Modeling of spouted beds by means of modern simulation tools, like discrete particle models or continuum models, has become a precious opportunity to understand the complexity of multiphase flows in these apparatus. In this work, two-dimensional continuum simulations of a novel kind of spouted bed apparatus with adjustable gas inlets are presented. Different gas-particle drag models are used to obtain a realistic flow structure. Simulated solid phase concentrations are compared with images taken during experiments. Furthermore, simulated and measured gas phase pressure fluctuations over the entire bed are contrasted allowing more accurate comparisons between the simulated and the real hydrodynamic behaviour of the spouted bed.Depuis l'invention de la technologie du lit jaillissant par Mathur et Gishler (1955), une grande variété de systèmes aété mise au point et un nombre considérable d'applications dans presque toutes les branches de l'industrie ont vu le jour. La modélisation de lits jaillissants au moyen d'outils de simulation modernes, tels que les modèles de particules discrets ou les modèles en continu, est une excellente occasion pour comprendre la complexité desécoulements multiphasiques dans ces appareils. Dans ce travail, des simulations en continu bidimensionnelles d'une nouveau type de lit jaillissant avec des entrées de gaz ajustables sont présentées. On a testé différents modèles de traînée gaz-particules pour obtenir une structure d'écoulement réaliste. Les concentrations de phases solides simulées sont comparéesà des images prises lors des expériences. Par ailleurs, les fluctuations de pression de phase gazeuse simulées et mesurées dans la totalité du lit sont contrastées, ce qui permet des comparaisons plus précises entre le comportement hydrodynamique simulé et réel du lit jaillissant.

Three‐Dimensional Computational Fluid Dynamics Modeling of a Prismatic Spouted Bed

“…However, the discrepancies between the simulation results and the experimental findings, like the under-prediction of bed expansion and too weak gas phase pressure fluctuations, are the same as in the two-dimensional calculations, as it was found out recently (Gryczka et al [7]). …”

“…9b) is dramatically under-predicted, as it was found out recently (Gryczka et al [7]). The bed expansion is in better agreement with the experiment by application of the Clift et al [9] drag model (see Fig.…”

“…In this work, three-dimensional CFD continuum simulations in a prismatic spouted-bed apparatus were presented and compared with two-dimensional results and experiments by Gryczka et al [7]. The apparatus depth was 400 mm and the simulations were performed by application of the Schiller and Naumann [10] drag model and the Clift et al [9] drag model.…”

“…Recently, Gryczka et al [7,8] found that the coupling between the phases (see Eq. 16) is of significant importance for the simulation of realistic flow structures.…”

“…In Gryczka et al [7,8], two-dimensional simulation results of a prismatic spouted bed with slit-shaped gas inlets under application of a CFD continuum model in the commercial software package FLUENT 6.2 were presented. The aim was to find a basic model to reproduce a realistic spouting process.…”