Characterization of the pneumatic behavior of a novel spouted bed apparatus

Recently the importance of spouted bed technology has significantly increased in the context of drying processes as well as granulation, agglomeration or coating processes. Particulate 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

Analysis of the fluidization behaviour and application of a novel spouted bed\ud apparatus for spray granulation and coating

Spouted beds are well known for their good mixing of the solid phase and for their intensive heat\ud and mass transfers between the fluid phase and the solid phase. Nearly isothermal conditions are\ud enabled which is of advantage for the treatment of granular solid materials in granulation,\ud agglomeration or coating processes. In this work the hydrodynamic behaviour of a novel spouted\ud bed apparatus with two horizontal and slit-shaped gas inlets is investigated by high-frequency\ud recordings of the gas phase pressure fluctuations over the entire bed. The hydrodynamic stable\ud operation domain, which is of importance for operating the apparatus, will be identified and\ud depicted in the Re-G-Ar-diagram by Mitev [1]. Another focus of this work is the simulation of the\ud spouting process by application of a continuum approach in FLUENT 6.2. The effect of the\ud frictional stresses on the hydrodynamic behaviour is examined by performing simulations with and\ud without consideration of friction. The angle of internal friction fi in Schaeffer`s [10] model will be\ud varied and the simulation results will be compared with experiments. It was found that the influence\ud of friction is not very big by application of the quite simple and empirical frictional viscosity model\ud by Schaeffer [10] basing on soil mechanical principles. Also the simulation results under negligence\ud of friction were similar to those under consideration of friction. Another part of this work is the\ud industrial application of the novel spouted bed in granulation and coating processes. Compared to\ud classical fluidized beds, a much narrower particle size distribution, a higher yield and a higher\ud product quality was obtained in the novel spouted be

Characterization of the pneumatic behavior of a novel spouted bed apparatus with two adjustable gas inlets

Recently the importance of spouted bed technology has significantly increased in the context of drying processes as well as granulation, agglomeration or coating processes. Particulate 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

Fichas de matemáticas

[spa] En un intento de adaptar la asignatura de Matemáticas de la licenciatura de Biología al Espacio Europeo de Enseñanza Superior (EEES), nacen las "Fichas Matemáticas". Estas fichas pretenden proporcionar al alumno los conceptos básicos que se tratarán en la asignatura, a fin de que tenga una base a partir de la cual pueda profundizar y trabajar dichas ideas conceptuales. Estas fichas son un resumen de los conceptos teóricos que deberá adquirir el alumno sobre esta asignatura obligatoria de Matemáticas.[cat] En un intent d'adaptar l'assignatura de Matemàtiques de la llicenciatura de Biologia a l'Espai Europeu de Ensenyança Superior (EEES), neixen les "Fichas Matemáticas". Aquestes fitxes pretenen proporcionar a l'alumne els conceptes bàsics que es tractaran en l'assignatura, amb la finalitat de que tingui una base a partir de la que pugui profunditzar i treballar aquestes idees conceptuals. Aquestes fitxes son un resum dels conceptes teòrics que haurà d'adquirir l'alumne sobre aquesta assignatura obligatòria de Matemàtiques.[eng] In order to the adaptation for the Mathematics for biologists to the Espai Europeu de Ensenyança Superior (EEES), appears the "Fichas Matemáticas". They try to give to the student the basic ideas of mathematics. They are a resume of theory that the student must to assume in this obligatory subject

Analysis of the fluidization behavior and application of a novel spouted bed apparatus for spray granulation and coating

Spouted beds are well known for their good mixing of the solid phase and for their intensive heat and mass transfers between the fluid phase and the solid phase. Nearly isothermal conditions are enabled which is of advantage for the treatment of granular solid materials in granulation, agglomeration or coating processes. In this work the hydrodynamic behaviour of a novel spouted bed apparatus with two horizontal and slit-shaped gas inlets is investigated by high-frequency recordings of the gas phase pressure fluctuations over the entire bed. The hydrodynamic stable operation domain, which is of importance for operating the apparatus, will be identified and depicted in the Re-G-Ar-diagram by Mitev [1]. Another focus of this work is the simulation of the spouting process by application of a continuum approach in FLUENT 6.2. The effect of the frictional stresses on the hydrodynamic behaviour is examined by performing simulations with and without consideration of friction. The angle of internal friction fi in Schaeffer`s [10] model will be varied and the simulation results will be compared with experiments. It was found that the influence of friction is not very big by application of the quite simple and empirical frictional viscosity model by Schaeffer [10] basing on soil mechanical principles. Also the simulation results under negligence of friction were similar to those under consideration of friction. Another part of this work is the industrial application of the novel spouted bed in granulation and coating processes. Compared to classical fluidized beds, a much narrower particle size distribution, a higher yield and a higher product quality was obtained in the novel spouted bed

Characterization of the pneumatic behavior of a novel spouted bed apparatus with two adjustable gas inlets

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

Characterization and CFD-modeling of the hydrodynamics of a prismatic spouted bed apparaturs

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