Experimental Study and Improvement of Mass Transfer in Vertical Bubble Columns

Experimental Study and Improvement of Mass Transfer in Vertical Bubble Columns PDF Author: Nicolas Souzy
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Bubble column are involved in many industrial fields ranging from chemical industry to mineral processing. It recently became an industrial stake for the production of micro-algae intended for medicinal use, food or energy: the oxygen and carbon dioxide concentrations can be controlled via the efficient mass transfer induced by the significant gas-liquid interfaciale area into the bubble column. Firstly, experimental closed-loop study has been carried out to simulate the passage of gas in a succession of columns in series. The associated theoretical model confirms the critical importance of the bubble diameter for mass transfer.Therefore, an innovative Micro-Bubble Generator (MBG) has been designed and tested. The prototype is able to produce micro-bubbles of average diameter Dbubble = 0.252 mm. The invention has been officially declared. The last chapter aims at improving data treatment methods for Planar Laser-Induced Fluorescence (PLIF), which enables to obtain experimentally mass transfer coefficient kl through concentration measurements. The first presented correction takes into account variations of the fluorescence extinction due to pH during the calibration step, and has been evaluated on CO2 concentration measurement in the wake of a free rising bubble. The second proposed correction should be applied when the length in the measurement region over which pH variations are observed increases: variations of the extinction coefficient will affect the local incident light intensity and therefore the measurements. The need for this correction has been illustrated on a test case in the wake of a cloud of free rising bubbles.

Experimental Study and Improvement of Mass Transfer in Vertical Bubble Columns

Experimental Study and Improvement of Mass Transfer in Vertical Bubble Columns PDF Author: Nicolas Souzy
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Bubble column are involved in many industrial fields ranging from chemical industry to mineral processing. It recently became an industrial stake for the production of micro-algae intended for medicinal use, food or energy: the oxygen and carbon dioxide concentrations can be controlled via the efficient mass transfer induced by the significant gas-liquid interfaciale area into the bubble column. Firstly, experimental closed-loop study has been carried out to simulate the passage of gas in a succession of columns in series. The associated theoretical model confirms the critical importance of the bubble diameter for mass transfer.Therefore, an innovative Micro-Bubble Generator (MBG) has been designed and tested. The prototype is able to produce micro-bubbles of average diameter Dbubble = 0.252 mm. The invention has been officially declared. The last chapter aims at improving data treatment methods for Planar Laser-Induced Fluorescence (PLIF), which enables to obtain experimentally mass transfer coefficient kl through concentration measurements. The first presented correction takes into account variations of the fluorescence extinction due to pH during the calibration step, and has been evaluated on CO2 concentration measurement in the wake of a free rising bubble. The second proposed correction should be applied when the length in the measurement region over which pH variations are observed increases: variations of the extinction coefficient will affect the local incident light intensity and therefore the measurements. The need for this correction has been illustrated on a test case in the wake of a cloud of free rising bubbles.

Detailed Experimental Study of Mass Transfer and Liquid Flow in a Bubble Column with Optical Measurement Techniques

Detailed Experimental Study of Mass Transfer and Liquid Flow in a Bubble Column with Optical Measurement Techniques PDF Author: Péter Miklós Kováts
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Bubbly Flows

Bubbly Flows PDF Author: Martin Sommerfeld
Publisher: Springer Science & Business Media
ISBN: 3642185401
Category : Science
Languages : en
Pages : 354

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Book Description
The book summarises the outcom of a priority research programme: 'Analysis, Modelling and Computation of Multiphase Flows'. The results of 24 individual research projects are presented. The main objective of the research programme was to provide a better understanding of the physical basis for multiphase gas-liquid flows as they are found in numerous chemical and biochemical reactors. The research comprises steady and unsteady multiphase flows in three frequently found reactor configurations, namely bubble columns without interiors, airlift loop reactors, and aerated stirred vessels. For this purpose new and improved measurement techniques were developed. From the resulting knowledge and data, new and refined models for describing the underlying physical processes were developed, which were used for the establishment and improvement of analytic as well as numerical methods for predicting multiphase reactors. Thereby, the development, lay-out and scale-up of such processes should be possible on a more reliable basis.

An Experimental and Computational Study of Hydrodynamics and Mass Transfer in Gas-liquid Bubble Columns

An Experimental and Computational Study of Hydrodynamics and Mass Transfer in Gas-liquid Bubble Columns PDF Author: Houman Shirzadi
Publisher:
ISBN: 9783844009460
Category :
Languages : en
Pages : 104

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Book Description


Hydrodynamics, Mixing, and Mass Transfer in Bubble Columns with Internals

Hydrodynamics, Mixing, and Mass Transfer in Bubble Columns with Internals PDF Author: Mohamed Hamed
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 123

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Book Description
Bubble columns and slurry bubble columns are considered reactors of choice for a wide range of applications in the chemical, biochemical, and petrochemical industries. Most of the chemical applications of bubble columns include exothermic processes and hence they require some means of heat removal to maintain a steady process. The most practical means for heat removal in these reactors is the utilization of vertical cooling internals since they provide high heat transfer area per reactor volume. However, the effects of these internals on the reactor performance are poorly understood in the open literature. This causes the design of the internals to be based on empirical rules not on the applications of fundamentals. The main objective of this study is to enhance the understanding of the effects of vertical cooling internals on the gas hydrodynamics, gas mixing, and mass transfer. In addition, this study attempts to develop and validate models that can simulate the radial gas velocity profile and axial gas mixing in the presence and absence of internals. Finally, this work aims to validate all the observed experimental results and models in larger columns with and without internals to have a better understanding of the scale-up effects in the presence of internals. This is accomplished by carrying out experiments in a lab-scale 8-inch bubble column and a pilot-scale 18-inch bubble column in the absence and presence of internals. The studied % occluded area by internals (~ 25%) is chosen to match the % occluded area used in the Fischer-Tropsch synthesis. The radial gas velocity profiles are measured using the 4-point optical probe and are used to validate the 1-D gas velocity model developed by Gupta (2002). Gar tracer techniques are used to study the effect of internals on the overall axial gas mixing and mass transfer. A 2-D model, that considers the radial variations of the gas velocity and gas holdup, is developed and used to analyze the tracer data allowing the estimation of the turbulent diffusivities of the gas phase. The 2-D model along with the axial dispersion coefficient model developed by Degaleesan and Dudukovic (1998) are used to determine the contribution of different mixing mechanisms to the overall axial gas mixing. The effect of internals and column diameter on the gas velocity profile, gas mixing, and mass transfer is assessed. The presence of internals causes: The effect of internals and column diameter on the gas velocity profile, gas mixing, and mass transfer is assessed. The presence of internals causes: An increase in the center-line gas velocity. A significant decrease in axial gas mixing. A decrease in the gas-liquid mass transfer coefficient. The increase in column diameter causes: Enhancement of the gas circulation. An increase in axial gas mixing. The model developed by Gupta (2002) to predict radial gas velocity profiles is validated at different operating conditions in the presence and absence of internals. A 2-D convection-diffusion model is developed and proven useful in interpreting gas tracer data and simulating the overall axial gas mixing in the presence and absence of internals.

An Experimental Study of Mass Transfer from a Single Gas Bubble

An Experimental Study of Mass Transfer from a Single Gas Bubble PDF Author: Gail R. Garbarini
Publisher:
ISBN:
Category : Mass transfer
Languages : en
Pages : 208

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Book Description


An Experimental Study of Free Convection Mass Transfer from High Vertical Surfaces to Liquids

An Experimental Study of Free Convection Mass Transfer from High Vertical Surfaces to Liquids PDF Author: Husband, W. H. W
Publisher: Saskatoon, Saskatchewan : Saskatchewan Research Council
ISBN:
Category :
Languages : en
Pages : 70

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Book Description


Heat and Mass Transfer

Heat and Mass Transfer PDF Author:
Publisher: BoD – Books on Demand
ISBN: 1789237726
Category : Technology & Engineering
Languages : en
Pages : 160

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Book Description
Heat and mass transfer are ubiquitous transport phenomena in many fields, from the natural environment and living organisms to the engineering process. This book focuses on the latest advances in applying fundamental heat and mass transfer theory and novel technologies for addressing a wide range of industrial problems of interest. This book will present readers with a recent analytical study, CFD modelling, and experimental investigations of heat and mass transfer topics associated with a variety of engineering disciplines including multiphase flow, nanofluids, porous media, battery thermal management, and engineering processes such as extractive distillation and arc welding. The book aims to provide new insights to understand the heat and mass transfer phenomena, serving as a platform for exchanging inspiring ideas and boosting further development of these disciplines.

Computational Science – ICCS 2019

Computational Science – ICCS 2019 PDF Author: João M. F. Rodrigues
Publisher: Springer
ISBN: 3030227472
Category : Computers
Languages : en
Pages : 675

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Book Description
The five-volume set LNCS 11536, 11537, 11538, 11539 and 11540 constitutes the proceedings of the 19th International Conference on Computational Science, ICCS 2019, held in Faro, Portugal, in June 2019. The total of 65 full papers and 168 workshop papers presented in this book set were carefully reviewed and selected from 573 submissions (228 submissions to the main track and 345 submissions to the workshops). The papers were organized in topical sections named: Part I: ICCS Main Track Part II: ICCS Main Track; Track of Advances in High-Performance Computational Earth Sciences: Applications and Frameworks; Track of Agent-Based Simulations, Adaptive Algorithms and Solvers; Track of Applications of Matrix Methods in Artificial Intelligence and Machine Learning; Track of Architecture, Languages, Compilation and Hardware Support for Emerging and Heterogeneous Systems Part III: Track of Biomedical and Bioinformatics Challenges for Computer Science; Track of Classifier Learning from Difficult Data; Track of Computational Finance and Business Intelligence; Track of Computational Optimization, Modelling and Simulation; Track of Computational Science in IoT and Smart Systems Part IV: Track of Data-Driven Computational Sciences; Track of Machine Learning and Data Assimilation for Dynamical Systems; Track of Marine Computing in the Interconnected World for the Benefit of the Society; Track of Multiscale Modelling and Simulation; Track of Simulations of Flow and Transport: Modeling, Algorithms and Computation Part V: Track of Smart Systems: Computer Vision, Sensor Networks and Machine Learning; Track of Solving Problems with Uncertainties; Track of Teaching Computational Science; Poster Track ICCS 2019 Chapter “Comparing Domain-decomposition Methods for the Parallelization of Distributed Land Surface Models” is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.

Bubble Column Reactions

Bubble Column Reactions PDF Author: Wolf-Dieter Deckwer
Publisher: John Wiley & Sons
ISBN:
Category : Science
Languages : en
Pages : 564

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Book Description
This technology, though used for many years, has shown great vitality recently and is still in a state of flux. Provides an account of developments up to the present and also an orderly evaluation of literature already published on the subject. Considerable space is devoted to bubble column reactor performance predictions based on mathematical models and the importance of each is explained with practical examples.