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 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 Essentials of Fluidization Technology written by John R. Grace and published by John Wiley & Sons. This book was released on 2020-03-19 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: A concise and clear treatment of the fundamentals of fluidization, with a view to its applications in the process and energy industries.
Download or read book Essentials of Fluidization Technology written by John R. Grace and published by John Wiley & Sons. This book was released on 2020-06-15 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt: A concise and clear treatment of the fundamentals of fluidization, with a view to its applications in the process and energy industries.
Download or read book Coal and Biomass Gasification written by Santanu De and published by Springer. This book was released on 2017-12-13 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the science and technology of the gasification process and the production of electricity, synthetic fuels and other useful chemicals. Pursuing a holistic approach, it covers the fundamentals of gasification and its various applications. In addition to discussing recent advances and outlining future directions, it covers advanced topics such as underground coal gasification and chemical looping combustion, and describes the state-of-the-art experimental techniques, modeling and numerical simulations, environmentally friendly approaches, and technological challenges involved. Written in an easy-to-understand format with a comprehensive glossary and bibliography, the book offers an ideal reference guide to coal and biomass gasification for beginners, engineers and researchers involved in designing or operating gasification plants.
Download or read book Fluidized Bed Reactors Processes and Operating Conditions written by John G. Yates and published by Springer. This book was released on 2016-09-27 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fluidized-bed reactor is the centerpiece of industrial fluidization processes. This book focuses on the design and operation of fluidized beds in many different industrial processes, emphasizing the rationale for choosing fluidized beds for each particular process. The book starts with a brief history of fluidization from its inception in the 1940’s. The authors present both the fluid dynamics of gas-solid fluidized beds and the extensive experimental studies of operating systems and they set them in the context of operating processes that use fluid-bed reactors. Chemical engineering students and postdocs as well as practicing engineers will find great interest in this book.
Download or read book Role of Mathematical Modeling in Advanced Power Generation Systems written by Arijit Ganguli and published by Frontiers Media SA. This book was released on 2023-11-13 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy demands throughout the globe has been increasing and the detrimental effects of carbon emissions on the environment by use of non-renewable resources has impacted life on the planet. The changing climate has caused an increase in natural calamities all over the globe. Many countries in the world have started to produce power using renewable resources like solar, biomass, wind energy, nuclear energy and green fuels. Though there are several technologies for power generation using the above sources, efficient design of these systems still needs lot of research. Mathematical modeling would play a vital role in design of state of the art technologies. Advanced nuclear power plants need special mention since they involve naturally driven safety systems where the complex phenomena of boiling, condensation and thermal stratification take place. These are difficult to model as there is more than one phase coupled with turbulence models, near wall phenomena, coalescence and break up, etc. Scaling up of such systems and their innovative design to reduce stratification requires the help of mathematical modeling. Other opportunities include Computational Fluid Dynamics (CFD) modeling for design of wind turbines for power generation using wind energy. Power generation from biomass involves use of gasifiers which has complex set of reactions and mostly two or three phases which are difficult to model using CFD at industrial scales.
Download or read book Hydrodynamics and Flow Structure Gas and Solids Mixing Behavior and Choking Phenomena in Gas solid Fluidization written by Bing Du and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this study, the dynamic flow behavior and gas and solids mixing behavior in the turbulent fluidized beds are investigated by using Electrical Capacitance Tomography (ECT) technique and tracer technique. The ECT study reveals that the time-averaged solids holdup distribution exhibits radial symmetry in the turbulent regime. The addition of 10% fine particles decreases the solids concentration in the emulsion phase. The flow behavior in the turbulent fluidized beds is not appreciably affected by the temperature up to 400 oC. More than one spiral motion of bubble swarms is observed in the bubbling regime for the 0.3 m ID fluidized bed. The gas and solids mixing behavior varies significantly with the flow regimes. A small quantity of fine particles is noted to drastically affect the gas and solids mixing behavior in the turbulent fluidized bed. For Group A particles, the flow in the bed transits from the dilute regime to the turbulent regime when the gas velocity is below Utr or the solids circulation rate is lower than Gs, tr. Such flow transition can be signified as the choking transition. For Group B particles, choking is initiated by the formation of the square-nosed slugs (0.05 m ID column) or the wall slugs (0.1 m ID CFB) when the gas velocity is below Utr or the solids circulation rate is lower than Gs, tr. When the gas velocity is above Utr or the solids circulation rate is higher than Gs, tr, choking is characterized by the formation of open slugs. These regime transitions are characterized as the choking transition. A model based on the movement of the solids blob at the center of the bed is developed to predict the critical lifetime of a solids blob in a circulating fluidized bed. The criterion for the occurrence of choking transition in a circulating fluidized bed for both Group A and Group B particles is given.
Download or read book Fluidization Engineering written by D. Kunii and published by Elsevier. This book was released on 2013-10-22 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluidization Engineering, Second Edition, expands on its original scope to encompass these new areas and introduces reactor models specifically for these contacting regimes. Completely revised and updated, it is essentially a new book. Its aim is to distill from the thousands of studies those particular developments that are pertinent for the engineer concerned with predictive methods, for the designer, and for the user and potential user of fluidized beds. Covers the recent advances in the field of fluidization. Presents the studies of developments necessary to the engineers, designers, and users of fluidized beds.
Download or read book Dispersion and Mass Transfer Coefficients in Fluidized Beds written by Mayank Kashyap and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This study covers three Geldart groups, and includes state-of-the-art experimental measurements and first-principles prediction... The authors solved a longstanding problem in fluidization, namely extremely low Sherwood number of fine particles in fluidized beds... The authors showed that the well-known core-annulus profile reverses in slugging fluidization of Geldart D particles due to particle inertia effects... This new finding is a robust and important one since core-annulus behavior is not desired... These contributions to the field of particle technology are of high impact, and expected to be of lasting influence..." -Christine Hrenya, Professor of Chemical and Biological Engineering, University of Colorado at Boulder. "The authors have shown that we can eliminate the core-annular regime in risers... By directly computing the mass transfer coefficients, the need to include empirical parameters could be eliminated to obtain more accurate conversion rates..."-Reza Mostofi, Ph.D., UOP, A Honeywell Company.
Download or read book Coupled CFD DEM Modeling written by Hamid Reza Norouzi and published by John Wiley & Sons. This book was released on 2016-10-17 with total page 436 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 Modeling and Flowsheet Simulation of Vibrated Fluidized Bed Dryers Band 18 written by Sören Ernst Lehmann and published by Cuvillier Verlag. This book was released on 2021-12-07 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluidized bed dryers are the prime choice when it comes to drying of heat sensitive products, commonly processed in the pharmaceutical and food industry. As many products in these industries are fine and cohesive, mechanical vibration of the dryer is used to enable or improve fluidization. Thus, the goal of this thesis is the development of a fluidized bed drying model that accounts for the influence of mechanical vibration of the dryer, as well as its implementation in an open-source flowsheet simulation framework. Continuously operated fluidized bed dryers under steady-state conditions are the focus of this thesis. The aim during model development and implementation is the broadest possible application range of the model. A custom-built vibrated fluidized bed dryer is designed and constructed for comprehensive investigations of fluidized bed hydrodynamics and drying kinetics. Based on experimental investigations, a semi-empirical model for hydrodynamics of fine and cohesive powders is developed. The new model is combined with established models to allow for the flowsheet simulation of fluidized bed dryers for particles of all Geldart groups. Additionally, the influence of vibration is accounted for. Comprehensive validation experiments are performed for particles of different Geldart groups, different dryer geometries and a variety of process parameters, including mechanical vibration. Comparison of model predictions with experimental data attributes high accuracy of predicted particle and gas properties. Furthermore, sensitivity analyses are conducted to identify potential weaknesses in underlying model assumptions. Hereby, the validity of underlying assumptions is confirmed and potential optimization parameters for different applications are identified. The proposed model is unprecedented in terms of range of process parameters, variety of particle properties and dryer geometries, tested and found valid for.
Download or read book Circulating Fluidized Beds written by J.R. Grace and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 599 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the late 1970s there has been an explosion of industrial and academic interest in circulating fluidized beds. In part, the attention has arisen due to the environmental advantages associated with CFB (circulating . fluidized bed) combustion systems, the incorporation of riser reactors employing cir culating fluidized bed technology in petroleum refineries for fluid catalytic cracking and, to a lesser extent, the successes of CFB technology for calcina tion reactions and Fischer-Tropsch synthesis. In part, it was also the case that too much attention had been devoted to bubbling fluidized beds and it was time to move on to more complex and more advantageous regime,S of operation. Since 1980 a number of CFB processes have been commercialized. There have been five successful International Circulating Fluidized Bed Confer ences beginning in 1985, the most recent taking place in Beijing in May 1996. In addition, we have witnessed a host of other papers on CFB funda mentals and applications in journals and other archival publications. There have also been several review papers and books on specific CFB topics. However, there has been no comprehensive book reviewing the field and attempting to provide an overview of both fundamentals and applications. The purpose of this book is to fill this vacuum.
Download or read book Modeling Approaches and Computational Methods for Particle laden Turbulent Flows written by Shankar Subramaniam and published by Academic Press. This book was released on 2022-10-20 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modelling Approaches and Computational Methods for Particle-laden Turbulent Flows introduces the principal phenomena observed in applications where turbulence in particle-laden flow is encountered while also analyzing the main methods for analyzing numerically. The book takes a practical approach, providing advice on how to select and apply the correct model or tool by drawing on the latest research. Sections provide scales of particle-laden turbulence and the principal analytical frameworks and computational approaches used to simulate particles in turbulent flow. Each chapter opens with a section on fundamental concepts and theory before describing the applications of the modelling approach or numerical method. Featuring explanations of key concepts, definitions, and fundamental physics and equations, as well as recent research advances and detailed simulation methods, this book is the ideal starting point for students new to this subject, as well as an essential reference for experienced researchers. Provides a comprehensive introduction to the phenomena of particle laden turbulent flow Explains a wide range of numerical methods, including Eulerian-Eulerian, Eulerian-Lagrange, and volume-filtered computation Describes a wide range of innovative applications of these models
Download or read book Fast Fluidization written by and published by Academic Press. This book was released on 1994-12-23 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last decade, circulating fluidization or fast fluidization has developed rapidly, superseding standard bubbling fluidization in many applications; for example, fast fluidization provides a better means forcontrolling emissions from the combustion of high-sulfur fuels and excels when used in boilers in steam plant and power stations. China initiated the study of fast fluidization in the early 1970s. Focusing on the substantial research cultivated in that country, with Kwauk at the leading edge, this latest volume in the Advances in Chemical Engineering Series is written in the context of the international state of the art and addresses some of the most vital issues surrounding this fluidization method."
Download or read book Multiphase Flow Handbook written by Efstathios Michaelides and published by CRC Press. This book was released on 2016-10-26 with total page 1421 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Multiphase Flow Handbook, Second Edition is a thoroughly updated and reorganized revision of the late Clayton Crowe’s work, and provides a detailed look at the basic concepts and the wide range of applications in this important area of thermal/fluids engineering. Revised by the new editors, Efstathios E. (Stathis) Michaelides and John D. Schwarzkopf, the new Second Edition begins with two chapters covering fundamental concepts and methods that pertain to all the types and applications of multiphase flow. The remaining chapters cover the applications and engineering systems that are relevant to all the types of multiphase flow and heat transfer. The twenty-one chapters and several sections of the book include the basic science as well as the contemporary engineering and technological applications of multiphase flow in a comprehensive way that is easy to follow and be understood. The editors created a common set of nomenclature that is used throughout the book, allowing readers to easily compare fundamental theory with currently developing concepts and applications. With contributed chapters from sixty-two leading experts around the world, the Multiphase Flow Handbook, Second Edition is an essential reference for all researchers, academics and engineers working with complex thermal and fluid systems.
Download or read book Dynamics of Non Spherical Particles in Turbulence written by Luis Blay Esteban and published by Springer. This book was released on 2019-08-13 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book studies the dynamics of 2D objects moving through turbulent fluids. It examines the decay of turbulence over extended time scales, and compares the dynamics of non-spherical particles moving through still and turbulent fluids. The book begins with an introduction to the project, its aims, and its relevance for industrial applications. It then discusses the movement of planar particles in quiescent fluid, and presents the numerous methodologies used to measure it. The book also presents a detailed analysis of the falling style of irregular particles, which makes it possible to estimate particle trajectory and wake morphology based on frontal geometry. In turn, the book provides the results of an analysis of physically constrained decaying turbulence in a laboratory setting. These results suggest that large-scale cut-off in numerical simulations can result in severe bias in the computed turbulent kinetic energy for long waiting times. Combining the main text with a wealth of figures and sketches throughout, the book offers an accessible guide for all engineering students with a basic grasp of fluid mechanics, while the key findings will also be of interest to senior researchers.
