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Item type:Publication, Access status: without files , Characterization and CFD-modeling of the hydrodynamics of a prismatic spouted bed apparatus(2009-07-15); ; ; ; Recently the importance of spouted bed technology has significantly increased in the context of drying processes as well as granulation, agglomeration or coating processes. However, the understanding of the complex interactions within and between the single phases is still low and needs further improvement. Several research groups apply both continuum as well as discrete element simulations to understand the hydrodynamics of the spouting process. This work focuses on the simulation of the hydrodynamic behavior of a prismatic spouted bed apparatus by applying the Euler/Euler continuum approach in the commercial computational fluid dynamics (CFD) software package FLUENT 6.2. The simulations are validated by experiments. Calculated and experimental (by PIV-measurements) obtained velocity vector maps, as well as measured and calculated gas phase pressure fluctuations over the entire bed are compared. The aim of this work is to improve the understanding of the hydrodynamics of the spouting process.Publicationtype: Journal Article29 - Some of the metrics are blocked by yourconsent settings
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 , Membrane assisted fluidized bed reactors: Potentials and hurdlesRecent advances in the development of more stable membranes with increased permeance have significantly enhanced the possibilities for integrating membranes into catalytic reactors in order to achieve a major increase in reactor performance by process integration and process intensification. Several reviews and even special issues of catalysis related journals illustrate the significant progress in the field of inorganic membrane reactors within the last two decades. Chemical engineers and material scientists have joined forces and addressed this topic from various view-points. In spite of their considerable efforts in these directions, the application of the membrane reactors, especially packed bed membrane reactors, in commercial processes has been very limited because of technical as well as economical drawbacks. The most recent trend in membrane reactor technology has been in the direction of incorporating inorganic membranes into fluidized beds to combine the perm-selective and controlled dosing capabilities of membranes with excellent gas-solid contact and heat transfer capabilities of fluidized beds, thereby overcoming the limitations often prevailing in packed bed membrane reactors. The opportunities for this novel fluidized bed membrane reactor compared to conventional reactors and packed bed membrane reactors have never been systematically reviewed before. This paper seeks to review literature and new developments in the area of membrane assisted fluidized bed reactors, with special emphasis on possible applications, integration of different membranes in the fluidized beds, reactor modelling studies, experimental demonstration of various reactor concepts and future prospects and hurdles for commercialization. Finally, an assessment of the state of the art has been given and directions for future research are indicated.Publicationtype: Journal Article12