Experimental and Simulated Solids Mixing and Bubbling Behavior in a Scaled Two-section Two-zone Fluidized Bed Reactor PDF Download

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Languages : en
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Author: John G. Yates
Publisher: Springer
ISBN: 3319395939
Category : Science
Languages : en
Pages : 214

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Book Description
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.

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Languages : en
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A stochastic model was developed that predicts the local dispersion of the solids in terms of the bubble frequency and bubble diameter in a freely bubbling fluidized bed. The predictions were confirmed by experimental measurements of dispersion and they are consistent with the results of previous investigations. The stochastic model was based on the equations of motion for a single particle and should prove useful for the description of the fluidized bed reactor especially in problems associated with catalyst decay in reactor-regenerator configurations. The model emphasizes the need to investigate the mechanism of the interaction between bubble and particle more completely. In particular the path followed by a particle during its passage around the bubble and in the wake is important for determining the vertical and lateral displacement during collision. Although the stochastic model can be reduced in the end to an effective axial mixing model, it has two very real advantages over the deterministic model. It provides the relationship between the effective axial mixing coefficient for the solids and the measurable properties of the bubbles in the bed. This is important because the bubble motion is the dominant factor in solids dispersion. In addition the stochastic model is capable of predicting the variation of the effective mixing coefficient with bed height. It could also be modified to allow precisely for the upper and lower surfaces of shallow beds.

Author: Guangwen Xu
Publisher: Elsevier
ISBN: 0443187193
Category : Technology & Engineering
Languages : en
Pages : 409

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Micro Fluidization: Fundamentals and Applications provides background and history on micro fluidized bed research and development, summarizes and analyzes the hydrodynamic characteristics of gas-solid micro fluidized beds, and delves into areas such as research results of delayed onsets of minimum, bubbling and slugging fluidization regimes, as well as of the advanced transitions to turbulent and fast fluidization regimes. Based on these results, the wall effects – the key mechanism resulting in the unique behavior of micro fluidization – are analyzed. Other sections discuss gas and solid mixing characteristics in terms of gas residence time distribution, gas backmixing, and solids mixing. Final sections focus on presentations of the so-called micro fluidized bed reaction analyzer (MFBRA) – a powerful tool for catalyst screening, process development, optimization of reaction parameters, studies of reaction mechanism and kinetics, among many other purposes. The book describes, in detail, the MFBRA’s system design characteristics, analytic methodologies and various applications in thermochemical and catalytic reaction analysis. Includes up-to-date information (all related research results and insights) on micro fluidized beds, including how they are comprehensively summarized and analyzed Describes and explains the unique characteristics of micro fluidized beds Covers the fundamental aspects and applications related to gas-solids, liquid-solids, and gas-liquid-solids micro fluidized beds Provides up-to-date and potential applications of micro fluidized beds

Author: Vivek V. Ranade
Publisher: Academic Press
ISBN: 0125769601
Category : Science
Languages : en
Pages : 476

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The book relates the individual aspects of chemical reactor engineering and computational flow modeling in a coherent way to explain the potential of computational flow modeling for reactor engineering research and practice.

Author: Wen-Ching Yang
Publisher: CRC Press
ISBN: 0203912748
Category : Science
Languages : en
Pages : 876

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Book Description
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.

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Publisher: Academic Press
ISBN: 0080565670
Category : Technology & Engineering
Languages : en
Pages : 453

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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."

Author: Akhilesh Bakshi
Publisher:
ISBN:
Category :
Languages : en
Pages : 173

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Book Description
Gas-solid fluidized bed reactors find many applications in the energy, chemical and biomedical industries because of their high heat and mass transfer. Their design and optimization continue to be a challenge; the dependence of mixing dynamics on operating conditions and the impact of the reactor scale are poorly understood. This is compounded by severe limitations on diagnostics in their harsh operating environment. Computational Fluid Dynamics (CFD) will play a pivotal role in advancing this technology since it enables unrestricted access inside the reactor, enhancing fundamental understanding of several coupled phenomena and their interactions at various scales. The thesis is focused on the bubbling fluidization of Geldart B particles (typically 103

Author: Dimitri Gidaspow
Publisher: Elsevier
ISBN: 0080512267
Category : Science
Languages : en
Pages : 489

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Book Description
Useful as a reference for engineers in industry and as an advanced level text for graduate engineering students, Multiphase Flow and Fluidization takes the reader beyond the theoretical to demonstrate how multiphase flow equations can be used to provide applied, practical, predictive solutions to industrial fluidization problems. Written to help advance progress in the emerging science of multiphase flow, this book begins with the development of the conservation laws and moves on through kinetic theory, clarifying many physical concepts (such as particulate viscosity and solids pressure) and introducing the new dependent variable--the volume fraction of the dispersed phase. Exercises at the end of each chapterare provided for further study and lead into applications not covered in the text itself. - Treats fluidization as a branch of transport phenomena - Demonstrates how to do transient, multidimensional simulation of multiphase processes - The first book to apply kinetic theory to flow of particulates - Is the only book to discuss numerical stability of multiphase equations and whether or not such equations are well-posed - Explains the origin of bubbles and the concept of critical granular flow - Presents clearly written exercises at the end of each chapter to facilitate understanding and further study

Author: Valter Bruno Reis e Silva
Publisher: Butterworth-Heinemann
ISBN: 0128175419
Category : Technology & Engineering
Languages : en
Pages : 220

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Book Description
Computational Fluid Dynamics Applied to Waste-to-Energy Processes: A Hands-On Approach provides the key knowledge needed to perform CFD simulations using powerful commercial software tools. The book focuses on fluid mechanics, heat transfer and chemical reactions. To do so, the fundamentals of CFD are presented, with the entire workflow broken into manageable pieces that detail geometry preparation, meshing, problem setting, model implementation and post-processing actions. Pathways for process optimization using CFD integrated with Design of Experiments are also explored. The book’s combined approach of theory, application and hands-on practice allows engineering graduate students, advanced undergraduates and industry practitioners to develop their own simulations. Provides the skills needed to perform real-life simulation calculations through a combination of mathematical background and real-world examples, including step-by-step tutorials Presents worked examples in complex processes as combustion or gasification involving fluid dynamics, heat and mass transfer, and complex chemistry sets