9 results
Now showing1 - 9 of 9
- Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Magnetic monitoring of a single particle in a prismatic spouted bed(2009-09-23); ; ; In this work a non-intrusive measuring technique for continuous tracking of a magnetic marked particle during fluidization in a prismatic spouted bed is presented. The magnetic monitoring system provides besides the spatial coordinates x, y and z the orientation of the particle, whereby the trajectory, the velocity, the acceleration as well as the rotation of the particle are obtained. It will be demonstrated that the characteristic particle trajectories and particle velocity distributions in dependency of the gas throughput and of the bed mass can be detected in this type of spouted bed. Furthermore, a calculated particle velocity distribution obtained by a CFD continuum simulation will be favorably compared with a measured distribution.Publicationtype: Journal Article17 - Some of the metrics are blocked by yourconsent settings
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 , Three-dimensional computational fluid dynamics modeling of a prismatic spouted bed(2009-05-20); ; ; ; Modern simulation tools like discrete particle models or continuum models have been established as precious methods to gain insight into the complex processes in fluidized and spouted beds. Valuable information on parameters influencing the hydrodynamics can be obtained directly from computer simulations. Numerous researchers applied two-dimensional discrete and continuum models to simulate fluidized and spouted beds. However, only few publications deal with three-dimensional continuum simulations, and very often results of three-dimensional experiments are compared with two-dimensional results. In this work, a three-dimensional simulation by application of a continuum model is presented in a prismatic spouted bed with slit-shaped gas inlets. Comparisons with two-dimensional simulations in the same geometry (Gryczka et al. 2009, Chem. Eng. Sci., in press) are also part of this publication. The influence of the third dimension on the hydrodynamic behavior (bubble formation, bubble size, etc.) will be discussed. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.Publicationtype: Journal Article21 - 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: with files , Untersuchung und Modellierung der Fluiddynamik in prismatischen Strahlschichtapparaten(2009); Recently the importance of spouted bed technology has significantly increased in the context of drying processes as well as granulation, agglomeration or coating. Within this work simula-tions of the fluid dynamics of a novel prismatic spouted bed by application of a CFD contin-uum model are presented and validated by numerous experiments. The simulation results are in good qualitative agreement with the experiments. However, quantitative discrepancies still exist. Moreover, the applicability of a magnetic monitoring device for tracking a single particle in the novel spouted bed is favourably examined.Publicationtype: Doctoral Thesis717 2025 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , CFD-modelling of the fluid dynamics in spouted bedsRecently the importance of the 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. Within this work, the hydrodynamical behaviour of a novel spouted bed apparatus is modelled by applying the Euler/Euler continuum approach in two dimensions in the commercial CFD software-package FLUENT 6.2. The focus of this study is the influence of different gas-particle drag models on the flow structure in the spouted bed apparatus. Simulated spatial distributions of the granular solid phase in the apparatus are compared with images taken during experiments. Characteristic gas phase fluctuations over the entire bed are simultaneously measured by a high frequency pressure detector and will be compared with calculated fluctuations. Also a Fourier analysis on the measured and simulated pressure frequency spectra will be demonstrated.Publicationtype: Book Part19 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Characterization of the pneumatic behavior of a novel spouted bed apparatus(2008-05); ; ; ; Recently the importance of spouted bed technology has significantly increased in the context of drying processes as well as granulation, agglomeration or coating processes. Par-ticulate systems concerning very fine or non spherical particles that are difficult to fluidize, often cannot be treated in conventional fluidized beds. In contrast to those fluidized beds, the spouted bed technology with its specific flow structure offers the opportunity of stable fluidization under controlled conditions. Within this work the fluid dynamics of a novel spouted bed with two adjustable gas inlets is investigated. By analysis of gas fluctuation spectra by means of a fast Fourier transformation algorithm, different operation regimes are identified and depicted graphically. Furthermore, continuum CFD-modeling of the granular solid phase motion by means of an Euler/Euler approach and comparisons with experimental obtained velocity vector fields by means of particle image velocimetry (PIV) measurements will be presented in this work.Publicationtype: Conference Paper10 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Characterization of the pneumatic behavior of a novel spouted bed apparatus with two adjustable gas inlets(2008-02); ; ; ; Recently the importance of spouted bed technology has significantly increased in the context of drying processes as well as granulation, agglomeration or coating processes. Within this work the fluid dynamics of a novel spouted bed plant with two adjustable gas inlets is investigated. By analysis of gas phase pressure fluctuation spectra by means of fast Fourier transformation algorithm and quantitative particle image velocimetry (PIV) measurements, different operation ranges will be identified and depicted graphically. A stable spouting range will be identified if a uniform and circulating particle motion without occurrence of dead zones is observable resulting in equal gas phase pressure fluctuations. Particle velocity vector maps as well as root mean square (rms) velocity plots provided by the PIV measurements confirm the results of the determination of the stable spouting range by analysis of the gas phase pressure fluctuations.Publicationtype: Journal Article16 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Untersuchungen zur Pneumatik von Strahlschichtapparaten mit schlitzförmigem Gaseintritt(2007-04); ; ; Strahlschichtapparate als Sonderfall von Wirbelschichtapparaten bieten effektive Möglichkeiten zur intensiven Kontaktierung von Fluid/Feststoffsystemen. Im Vergleich zu den Wirbelschichtapparaten haben die Strahlschichtapparate einige Vorteile. Für die Ermittlung der Wirksamkeit des Fluid/Feststoff-Kontakts ist die Kenntnis der Fluid-Verteilung in einer Strahlschicht sehr wichtig. Ziel der vorliegenden Arbeit ist die Untersuchung der Fluiddynamik von zwei Strahlschichtapparaten unterschiedlicher Größe mit schlitzförmigem Gaseintritt.Publicationtype: Review Article23