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Item type:Publication, Access status: without files , CFD modeling of a prismatic spouted bed with two adjustable gas inletsSince 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 I'invention de la technologie du lit jaillissant par Mathur et Gishler (1955), unegrande variété de systèmes a été mise au point et un nombre considérable d'applications dans presque toutes les branches de I'industrie ont vu le jour. La modelisation de I its jaillissants au moyen d'outils de simulation modemes, tels que les modeles de particules disc rets ou les modeles en continu, est une excellente occasion pour comprendre la complexité des écoulements multiphasiques dans ces appareils. Dans ce travail, des simulations en continu bidimensionnelles d'une nouveau type de lit jaillissant avec des entrees de gaz ajustables sont présentées. On a testé différents modèles de trainée gaz-particules pour obtenir une structure d'écoulement réafiste. Les concentrations de phases solides simulées sont comparées a 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 precises entre le comportement hydrodynamique simule et reel du lit jaillissant. © 2009 Canadian Society for Chemical Engineering.Publicationtype: Journal Article16 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Numerical bifurcation analysis of the nonlinear dynamics in continuous fluidized bed spray granulation systems(2006-04); ; ; ; Nonlinear oscillations in continuous fluidized bed spray granulation with external product classification are analyzed. Using methods from numerical bifurcation analysis the size and location of the instability regions in the space of the design parameters and the adjustable operating parameters are predicted and discussed. Analysis is based on a new relatively simple population balance model, which is formulated on a mass basis and provides first qualitative insights into the nonlinear dynamic behavior of continuous fluidized bed spray granulation processes.Publicationtype: Conference Paper10 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Non-stationary drying kinetics in a batch pharmaceutical fluidized bed coating process(2000-10); ; ; In this paper a physically based mathematical model for the description of particle wetting, temperature and humidity characteristics during a non-stationary fluidized bed spray-drying of granules or during a non-stationary fluidized bed coating in a Huttlin-Kugelcoater HKC 05-TJ is introduced. Using this model it is possible to calculate the humidity and temperature of the air, the degree of particle wetting, the temperatures of both the liquid layer and the particles under consideration and the influence of the wall of the apparatus and its surroundings. The effects of start-up and shut-down processes on the results as well as the time dependence of the discontinuous process with varying process parameters such as the amount of liquid sprayed in and its temperature, the amount of fluidising air and its temperature are simulated and the results were compared with those obtained experimentally using a Huttlin-Kugelcoater HKC 05-TJ. Furthermore, the growth of the bed and the increase of particle masses during a discontinuous coating and granulation processes were taken into account in a simplified manner.Publicationtype: Journal Article11