Download or read book Predicting the Performance of Different Fluidized and Spouted Beds for Spray Granulation Using CFD DEM Simulations written by Paul Kieckhefen and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluidized bed spray granulation is the preferred way of generating functional, high value granular products. By injecting a solution or suspension onto a fluidized particle bed, the particles grow layer by layer. The process conditions, specifically the drying potential, influence the state of the spray droplets when they impinge on the particles, for example the droplet viscosity and the relative velocity. Both quantities affect the spreading behavior of droplets on the surface, together with the crystallization occurring within the droplets themselves in the case of solutions, resulting in either porous or dense layers. As these phenomena are well accessible in CFD-DEM simulations, their combination can be a powerful tool in the design of granulators that produce tailor-made particles. A concept to realize this goal is presented: The surface structure of granulation products is measured for a variety of different process conditions in small-scale experiments. These experiments are replicated in silico using CFD-DEM, tracking the state of the droplets at impact, as well as the time for the evaporation of liquid layer on the particle surfaces. A mapping between these particle-scale quantities from the simulations and the resulting surface properties in experiments is derived, avoiding the direct dependency process conditions that may be very inhomogeneous in larger apparatuses. The concept is applied to evaluate the influence of granulator geometry (fluidized bed, spouted bed), nozzle configuration (top-spray nozzle, bottom-spray nozzle) and stabilizing internals (Wurster tube, draft plates) on the surface structure of granulation products.
Download or read book Predicting Product Properties of Fluidized Bed Spray Granulation Using CFD DEM Simulations written by Paul Kieckhefen and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Novel Method for Predicting Product Properties in Fluidized Bed Spray Granulation Band 19 written by Paul Kieckhefen and published by Cuvillier Verlag. This book was released on 2022-01-03 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluidized bed spray granulation is a process that facilities particle size enlargement by injecting solids in the form of a suspension, solution or melt. The produced particles are often of high value due to their highly specific, functionalized nature. This work provides a method for utilizing particle-scale simulations method like the coupled Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) to predict the properties of particles produced in scaled-up apparatuses based on laboratory-scale experiments by correlating the conditions that particle experience to the properties they develop. Furthermore, a method for calibrating DEM models of weakly wetted particle systems by utilizing a novel, probabilistic liquid bridge state model is proposed.
Download or read book Discrete particle modeling of a fluidized bed granulator written by Lennart Fries and published by Cuvillier Verlag. This book was released on 2012-10-29 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Size-enlargement and structuration processes in fluidized beds such as granulation and agglomeration play an important role in the pharmaceutical and fine chemical industries as well as in food technology to improve the flowability and the instant properties of solid products. Dustfree and free-flowing particles can be produced in a process with favourable heat- and mass transfer conditions. Furthermore, this technology allows the formulation of particles with novel functionalities by applying coating layers or via the encapsulation of active ingredients. Several interdependent micro mechanisms including particle collisions, wetting, drying and phase transitions govern the process dynamics and complicate predictions on the effect of variable operating conditions on product properties such as structure, strength and re-dissolution behaviour. Profound knowledge on these mechanisms is needed to understand the influence of individual process parameters on the final product properties. A suitable approach to model the particle interactions in fluidized beds is the Discrete Element Method (DEM) coupled with Computational Fluid Dynamics (CFD). Information on gas and particle velocities, particle rotation and collision dynamics, which are very complicated to measure in fluidized beds, can be studied in detail with this technique. This thesis presents DEM-CFD simulation results for three different granulator configurations (top-spray, Wurster-coater, spouted bed) in comparison to experimental results, regarding the agglomeration of amorphous maltodextrin (DE 21). In simulation and experiment the identical geometry of the equipment was used. Mechanical material properties, such as the coefficient of restitution and the Young’s modulus, which are required for the DEM model and which are frequently used as fitting parameters, were measured via static and dynamic deformation tests using maltodextrin agglomerates, beads and bars. The strength of the experimentally produced agglomerates was characterized with a compression tester. Their flow behaviour was assessed with the help of a shear cell. Very promising results were obtained showing that the homogeneity of particle wetting can well be approximated with the residence time distribution of the particles inside the spray zone.Homogeneous wetting allows achieving a narrow product size distribution (Fries et al., 2011a).Furthermore, the growth rate of the agglomerates can well be correlated with the simulated wetting intensity, the collision frequency and the collision velocity distribution inside the spray zone. The agglomerate strength shows a strong correlation with the particle-wall collision frequency and velocity distribution found in the simulations. Good agreement was found between the simulation results for the maximum particle deformation and for the energy dissipation during collisions and the measured deformation at the breakage point and the breakage energy. Due to the high numerical effort, DEM is only suitable for small scale applications. However, the obtained information on the kinetics of particle-particle interactions can be applied as input for macroscopic process models in the framework of a multi scale modeling scheme (Fries et al., 2011b; Werther et al., 2011). It can be concluded that DEM is a powerful tool for the detailed characterization of fluidized bed granulators. Highly relevant practical answers can be obtained from the model such as the choice of the optimal equipment geometry depending on material properties and product requirements. The model can point out where to position the spray nozzles in order to achieve homogeneous particle wetting and if a draft tube is helpful to maintain stable particle circulation. Based on such findings the model shows potential to increase the throughput of a fluidized bed granulator, while avoiding a bed collapse.
Download or read book Fluidization behavior and liquid injection in three dimensional prismatic spouted beds written by Swantje Pietsch and published by Cuvillier Verlag. This book was released on 2019-01-15 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this PhD thesis, the flow stability in a laboratory three-dimensional prismatic spouted bed is investigated both experimentally and in CFD-DEM simulations. Liquid is injected in bottom-spray configuration with the aim of a homogeneous distribution of the coating suspension on the whole particle bed. The range of stable spouting is increased by the installation of two parallel draft plates. Nevertheless, the instable spouting regime is found to be advantageous for obtaining a homogeneous coating as the draft plates prevent the mixing in the depth of the apparatus. In addition to the investigations on laboratory scale, the residence time behavior in a continuous pilot scale spouted bed is characterized using a novel tracer method with magnetizable particles. The back-mixing in the apparatus is reduced by the insertion of separation plates with defined transfer geometries.
Download or read book Spouted and Spout Fluid Beds written by Norman Epstein and published by Cambridge University Press. This book was released on 2010-12-23 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the pioneering text by Mathur and Epstein over 35 years ago, much of the work on this subject has been extended or superseded, producing an enormous body of scattered literature. This edited volume unifies the subject, pulling material together and underpinning it with fundamental theory to produce the only complete, up-to-date reference on all major areas of spouted bed research and practice. With contributions from internationally renowned research groups, this book guides the reader through new developments, insights and models. The hydrodynamic and reactor models of spouted and spout-fluid beds are examined, as well as such topics as particle segregation, heat and mass transfer, mixing and scale-up. Later chapters focus on drying, particle-coating and energy-related applications based on spouted and spout-fluid beds. This is a valuable resource for chemical and mechanical engineers in research and industry.
Download or read book CFD DEM Study of Effect of Bed Thickness for Bubbling Fluidized Beds written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of bed thickness in rectangular fluidized beds is investigated through the CFD-DEM simulations of small-scale systems. Numerical results are compared for bubbling fluidized beds of various bed thicknesses with respect to particle packing, bed expansion, bubble behavior, solids velocities, and particle kinetic energy. Good two-dimensional (2D) flow behavior is observed in the bed having a thickness of up to 20 particle diameters. However, a strong three-dimensional (3D) flow behavior is observed in beds with a thickness of 40 particle diameters, indicating the transition from 2D flow to 3D flow within the range of 20-40 particle diameters. Comparison of velocity profiles near the walls and at the center of the bed shows significant impact of the front and back walls on the flow hydrodynamics of pseudo-2D fluidized beds. Hence, for quantitative comparison with experiments in pseudo-2D columns, the effect of walls has to be accounted for in numerical simulations.
Download or read book Dynamic Flowsheet Simulation of Solids Processes and Its Application to Fluidized Bed Spray Granulation written by Maksym Dosta and published by . This book was released on 2015-10 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coupled CFD DEM Modeling written by Hamid Reza Norouzi and published by John Wiley & Sons. This book was released on 2016-10-21 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discusses the CFD-DEM method of modeling which combines both the Discrete Element Method and Computational Fluid Dynamics to simulate fluid-particle interactions. Deals with both theoretical and practical concepts of CFD-DEM, its numerical implementation accompanied by a hands-on numerical code in FORTRAN Gives examples of industrial applications
Download or read book Computational Fluid Dynamics CFD Simulation of a Gas Solid Fluidized Bed Residence Time Validation Study written by Baru Debtera and published by . This book was released on 2021-11-05 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Academic Paper from the year 2021 in the subject Physics - Mechanics, language: English, abstract: In this study, numerical simulations of a gas-solid fluidized bed reactor involving a two-fluid Eulerian multiphase model and incorporating the Kinetic Theory of Granular Flow (KTGF) for the solids phase have been performed using a commercial Computational Fluid Dynamics (CFD) software. The fluidized bed setup consists of 1,5 m height and 0,2 m diameter in which a series of experiments were performed using Helium tracer to determine the Residence Time Distribution (RTD) at various normalized velocities i.e., with different degrees of gas-solids mixing. Both 2D and 3D simulations of the fluidized bed reactor are performed. The main purpose of this study is to understand the hydrodynamic behavior of a gas-solid fluidized bed reactor through a framework of Eulerian multiphase model and to analyze hydrodynamic behavior of the gas-solids mixing.
Download or read book Mesoscale Modeling in Chemical Engineering Part I written by and published by Academic Press. This book was released on 2015-11-26 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focusing Mesoscales of Multiscale Problems in Chemical Engineering, a volume in the Advances in Chemical Engineering series provides readers with the personal views of recognized authorities who present assessments of the state-of-the-art in the field and help readers develop an understanding of its further evolution. Subjects covered in the book are not limited to the classical chemical engineering disciplines. Contributions connecting chemical engineering to related scientific fields, either providing a fundamental basis or introducing new concepts and tools, are encouraged. This volume aims to create a balance between well developed areas such as process industry, transformation of materials, energy, and environmental issues, and areas where applications of chemical engineering are more recent or emerging. Contains reviews by leading authorities in their respective areas Provides up-to-date reviews of the latest techniques in the modeling of catalytic processes Includes a broad mix of US and European authors, as well as academic/industrial/research institute perspectives Provides discussions on the connections between computation and experimental methods
Download or read book Fluid Dynamics of Turbulent Fluidized Beds for Geldart s Group B Particles written by Tom Wytrwat and published by Cuvillier Verlag. This book was released on 2022-02-15 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: An in-depth experimental study of the fluid dynamics of turbulent fluidized beds with particles of Geldart’s Group B was carried out. For this purpose, fluidization behavior was investigated in different fluidized bed plants having diameters in the range of 0.05 m to 1 m. Pressure fluctuation analysis has been used as an identification tool for the turbulent fluidized bed regime. Different fluidization conditions have been investigated by variation of the fluidized bed properties, the bed material properties, and the gas properties. Based on the measured data, a correlation predicting the transition velocity from bubbling to turbulent fluidization is introduced. To investigate the local flow structure, capacitance probe measurements have been carried out. Using this measurement technique, local solids concentrations and properties of rising bubbles have been determined and analyzed. Finally, an empiric fluid dynamic model was developed using the local measurement data. It is mainly based on capacitance probe measurements and shows high accuracy in comparison to pressure data.
Download or read book Development of Two way Coupled CFD DEM Model for Top Spray Fluid Bed Granulator Using Star CCM written by Dheeraj Reddy Devarampally and published by . This book was released on 2017 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Fluid Dynamics Simulation of Spray Dryers written by Meng Wai Woo and published by CRC Press. This book was released on 2016-11-03 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridging the gap in understanding between the spray drying industry and the numerical modeler on spray drying, Computational Fluid Dynamics Simulation of Spray Dryers: An Engineer’s Guide shows how to numerically capture important physical phenomena within a spray drying process using the CFD technique. It includes numerical strategies to effectively describe these phenomena, which are collated from research work and CFD industrial consultation, in particular to the dairy industry. Along with showing how to set up models, the book helps readers identify the capabilities and uncertainties of the CFD technique for spray drying. After briefly covering the basics of CFD, the book discusses airflow modeling, atomization and particle tracking, droplet drying, quality modeling, agglomeration and wall deposition modeling, and simulation validation techniques. The book also answers questions related to common challenges in industrial applications.
Download or read book Monte Carlo Simulation of Fluidized Bed Spray Agglomeration written by Korina Terrazas Velarde and published by . This book was released on 2010 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluid Dynamics of Turbulent Fluidized Beds for Geldart s Group B Particles written by Tom Wytrwat and published by SPE-Schriftenreihe 20. This book was released on 2022-02-15 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: An in-depth experimental study of the fluid dynamics of turbulent fluidized beds with particles of Geldart's Group B was carried out. For this purpose, fluidization behavior was investigated in different fluidized bed plants having diameters in the range of 0.05 m to 1 m. Pressure fluctuation analysis has been used as an identification tool for the turbulent fluidized bed regime. Different fluidization conditions have been investigated by variation of the fluidized bed properties, the bed material properties, and the gas properties. Based on the measured data, a correlation predicting the transition velocity from bubbling to turbulent fluidization is introduced. To investigate the local flow structure, capacitance probe measurements have been carried out. Using this measurement technique, local solids concentrations and properties of rising bubbles have been determined and analyzed. Finally, an empiric fluid dynamic model was developed using the local measurement data. It is mainly based on capacitance probe measurements and shows high accuracy in comparison to pressure data.
Download or read book Handbook of Fluidization and Fluid Particle Systems written by Wen-Ching Yang and published by CRC Press. This book was released on 2003-03-19 with total page 876 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference details particle characterization, dynamics, manufacturing, handling, and processing for the employment of multiphase reactors, as well as procedures in reactor scale-up and design for applications in the chemical, mineral, petroleum, power, cement and pharmaceuticals industries. The authors discuss flow through fixed beds, elutriation and entrainment, gas distributor and plenum design in fluidized beds, effect of internal tubes and baffles, general approaches to reactor design, applications for gasifiers and combustors, dilute phase pneumatic conveying, and applications for chemical production and processing. This is a valuable guide for chemists and engineers to use in their day-to-day work.
