Download or read book Fluid and Suspension Hydrodynamics in the Impeller Discharge Flow of Stirred Tanks written by Ziyun Yu and published by . This book was released on 2004 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrodynamics of Pumps written by Christopher E. Brennen and published by Cambridge University Press. This book was released on 2011-03-28 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrodynamics of Pumps is a reference for pump experts and a textbook for advanced students. It examines the fluid dynamics of liquid turbomachines, particularly pumps, focusing on special problems and design issues associated with the flow of liquid through a rotating machine. There are two characteristics of a liquid that lead to problems and cause a significantly different set of concerns than those in gas turbines. These are the potential for cavitation and the high density of liquids, which enhances the possibility of damaging, unsteady flows and forces. The book begins with an introduction to the subject, including cavitation, unsteady flows and turbomachinery, basic pump design and performance principles. Chapter topics include flow features, cavitation parameters and inception, bubble dynamics, cavitation effects on pump performance, and unsteady flows and vibration in pumps - discussed in the three final chapters. The book is richly illustrated and includes many practical examples.
Download or read book Hydrodynamics and Mixing in Stirred Tanks written by Ochieng Aoyi and published by LAP Lambert Academic Publishing. This book was released on 2009-11 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrodynamics in a mixing tanks results from the interaction between the tank geometry and the performance characteristics of the tank internals such as impeller and draft tube. In this book, the standard stirred tank configurations are investigated using both laser Doppler velocimetry (LDV) and computational fluid dynamics (CFD) techniques. The work first focuses on establishing the velocity field in a liquid-only system and then progresses to a solid-liquid system. In the liquid only system, it is shown that a draft tube can be used in a tank stirred by the Rushton turbine, and this improves mixing efficiency and reduces power consumption. For the solid-liquid systems, CFD simulation techniques are developed to determine multiphase mixing features such as cloud height and off-bottom suspension. Poly-disperse multiphase simulation results show the effect of particle size distribution and that of the drag model. The results provide useful information for process optimization and scale up.
Download or read book Hydrodynamics of Suspensions written by Marius Ungarish and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: Attention is focused on a suspension of buoyant particles (or droplets) in acontinuous fluid. In the presence of a force field, gravitational or centrifugal, and exposed to ordinary boundary constraints, a variety of fascinating flows can be obtained. These motions are essential ingre- dients in the widely used separation technology, where im- provedand new designs may be beneficial, but they are also interesting from a broader, academic point of view. In these respects, the recent investigations on these flows patterns, their underlying mechanisms and mathematical modeling - have accrued to a significant, relevant body of knowledge. The main objective of this book is to summarize - in a systematic, coherent and consistent fashion - the theoretical up to date contributions which seem fundamental in understanding, simulation and development of the subject.
Download or read book Processing of Solid Liquid Suspensions written by P. Ayazi Shamlou and published by Elsevier. This book was released on 2016-08-10 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: Processing of Solid-Liquid Suspensions is a collection of articles from several industrialists and academicians who are active in fundamental and applied research relating to handling and processing of particles in liquids. This collection of papers deals with the processes of interaction of particles with each other, with the surrounding liquid and process equipment, whereby knowledge of the mechanism of these interactions can be a sound basis for improving the design of the process equipment and create an optimum environment for the formation and processing of the particulate. The above notion is explained through analysis of the role of turbulent aggregation and breakup of particles in the formation of many solid products from aqueous solutions. This book also analyzes particle size and particulate crystals, whether as final products or as intermediates during processing. In the purification of proteins, two essential units of operation are used; precipitation and solid-liquid separation are analyzed, where theoretical considerations are reviewed. This text also discusses the application of model suspensions in the design of aerobic fermenters in practical industrial uses. High concentration of suspension preparations and solid suspension in liquid flourized beds or in stirred vessels are explained in more detail as to how these affect certain industries. This selection finally presents the progress made in developing design and methods needed by industry. Researchers, chemists, and scientists in industry, as well as advanced students with interests in formation and processing of stable suspensions and in advanced process engineering courses will find this textbook a valuable aid.
Download or read book Investigation of Turbulence Modulation in Solid liquid Suspensions Using FPIV and Micromixing Experiments written by Heema Unadkat and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this thesis is the study of turbulent solid-liquid stirred suspensions, which are involved in many common unit operations in the chemical, pharmaceutical and food industries. The studies of two-phase flows present a big challenge to researchers due to the complexity of experiments; hence there is a lack of quantitative solid and liquid hydrodynamic measurements. Therefore, an investigation of turbulence modulation by dispersed particles on the surrounding fluid in stirred vessels has been carried out, via two-phase fluorescent Particle Image Velocimetry (FPIV) and micromixing experiments. The main property of interest has been the local dissipation rate, as well as root-mean-square (rms) velocities and turbulent kinetic energy (TKE) of the fluid. Initially a single-phase PIV study was conducted to investigate the flow field generated by a sawtooth (EkatoMizer) impeller. The purpose of this study was to gain insight into various PIV techniques before moving on to more complex two-phase flows. Subsequently stereo-, high-speed and angle-resolved measurements were obtained. The EkatoMizer formed a good case study as information regarding its hydrodynamics is not readily available in literature, hence knowledge has been extended in this area. An analysis of the mean flow field elucidated the general structure of fluid drawn into the impeller region axially and discharged radially; the latter characterised the impeller stream. The radial rms velocity was considered to represent best the system turbulence, even though the tangential rms velocity was greater close to the blade; however the radial component was more prevalent in the discharge stream. Due to differences in rms velocities, TKE estimates obtained from two and three velocity components deviated, being greater in the latter case. Integral (1-D and 2-D) length scales were overestimated by the quantity W/2 in the impeller region. Ratios of longitudinal-to-lateral length scales also indicated flow anisotropy (as they deviated from 2:1). The anisotropy tensor showed that the flow was anisotropic close to the blade, and returned to isotropy further away from the impeller. Instantaneous vector plots revealed vortices in the discharge stream, but these were not associated with flow periodicity. Alternatively, the vortex structures were interpreted as low frequency phenomena between 0-200 Hz; macro-instabilities were found to have a high probability of occurrence in the discharge stream. Dissipation is the turbulent property of most interest as it directly influences micromixing processes, and its calculation is also the most difficult to achieve. Its direct determination from definition requires highly resolved data. Alternative methods have been proposed in the literature, namely dimensional analysis, large eddy simulation (LES) analogy and deduction from the TKE balance. All methods were employed using 2-D and 3-D approximations from stereo-PIV data. The LES analogy was deemed to provide the best estimate, since it accounts for three-dimensionality of the flow and models turbulence at the smallest scales using a sub-grid scale model. This method was carried forward to the analysis of two-phase PIV experiments. Turbulence intermittency of dissipation was assessed against the multifractal model of Meneveau and Sreenivasan (1991) and on that basis, the global standard deviation filter was considered most suitable for vector validation. The distribution of energy dissipation was calculated; it was estimated that 96% was dissipated in the impeller region. The ratio of maximum-to-mean energy dissipation compared well to other impellers, creating uncertainty about its reported high-shear attributes. After sufficient analyses of the single-phase EkatoMizer flow had been completed, investigation of two-phase flows began. Fluorescent Particle Image Velocimetry (FPIV) and digital image analysis techniques were combined, to quantify the hydrodynamics of solid-liquid suspensions stirred by a 45? pitched blade turbine impeller. Soda-lime glass spheres of sizes 250-300, 700-750 and 1000?m were employed for the dispersed phase, up to volumetric concentrations of 0.3, 0.5 and 0.5 vol% in water, respectively. The continuous phase mean velocity did not change significantly in the impeller jet or bulk flow, with the addition of up to 0.5 vol% dispersed phase. The 250-300 and 1000?m particles were found to suppress the carrier phase turbulence, in terms of rms velocities, turbulent kinetic energy and dissipation rate above particle concentrations of 0.2 vol%. The level of turbulence suppression remained constant up to 0.5 vol%. Greatest impact was on the dissipation rate, which decreased at most 25% in the discharge stream. Continuous phase integral length scales remained unchanged in the presence of solids. The locally averaged particle concentration field showed high concentrations above and below the impeller and at the corner of the vessel base. Particle turbulence levels measured at 0.5 vol% dispersed phase were lower than the corresponding fluid, and showed relatively higher anisotropy. The terminal velocity under estimated the slip velocity of the 1000 and 700-750?m particles in the impeller discharge, by a factor of five and nine respectively. Finally, two-phase micromixing experiments were carried out using both Bourne and Villermaux reaction schemes, to determine how the presence of particles affects the by-product distribution. In this way, the consequence on the dissipation rate was inferred indirectly. As these experiments did not depend on transparency of the mixture, experiments could be carried out with up to 1.75 vol% particles in the Bourne scheme and 3 vol% in the Villermaux scheme (operated at 500 and 800 rpm respectively). The common findings were that both small and large size classes (i.e. 70-100, 250-300 and 1000?m particles) increased the by-product yields and subsequently suppressed the dissipation rate. These results substantiated the earlier two-phase PIV observations. In the case of smaller particles (70-100 and 250-300?m), the maximum turbulence suppression occurred at ~1 vol%. Above this concentration, the level of suppression decreased and in some cases the regime switched to augmentation, indicating that particle concentration as well as size is important. In both FPIV and micromixing experiments, the finding of larger particles suppressing turbulence contradicts one of the most influential theories of Gore and Crowe (1989), which suggests that particles with diameter-to-integral length scale ratio greater than 0.1 create augmentation. Finally an experimental flow model (to accompany the engulfment model of micromixing) was proposed for a PBT stirred flow and evaluated against the single-phase micromixing results.
Download or read book Hydrodynamic Instabilities written by François Charru and published by Cambridge University Press. This book was released on 2011-06-30 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt: The instability of fluid flows is a key topic in classical fluid mechanics because it has huge repercussions for applied disciplines such as chemical engineering, hydraulics, aeronautics, and geophysics. This modern introduction is written for any student, researcher, or practitioner working in the area, for whom an understanding of hydrodynamic instabilities is essential. Based on a decade's experience of teaching postgraduate students in fluid dynamics, this book brings the subject to life by emphasizing the physical mechanisms involved. The theory of dynamical systems provides the basic structure of the exposition, together with asymptotic methods. Wherever possible, Charru discusses the phenomena in terms of characteristic scales and dimensional analysis. The book includes numerous experimental studies, with references to videos and multimedia material, as well as over 150 exercises which introduce the reader to new problems.
Download or read book Pumps and Blowers written by Alexey Joakim Stepanoff and published by . This book was released on 1965 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solids Suspension and Power Dissipation in Stirred Tanks Agitated by an Impeller Near the Tank Bottom written by Ernesto Uehara-Nagamine and published by . This book was released on 1996 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the effect of very small impeller clearances off the tank bottom, C, on complete solid off-bottom suspension, Njs, was investigated. Four types of impellers were used six-blade flat-disk turbine, six-blade flat-blade turbine, six-blade flat (45 degreees) pitched-blade turbine, and the high efficiency impeller Chemineer HE-3. The effects of the impeller diameter, D, tank diameter, T, and solids loading, X, were quantified. The presence of two impellers was analyzed using impellers of the same type and size. Typically, Njs and the power consumption were found to decrease with the impeller clearance. However, for lower C/T values, a slight increase was observed for axial impellers, especially for lower D/T ratios (less than 0.261). The power consumption was lower for the axial-flow impellers as compared with teh radial-flow impellers. For disk and flat-blade turbines, a change in the flow pattern was observed in teh range of 0.13
Download or read book Design Simulation and Optimization of Hydraulic Machinery written by Ling Zhou and published by Frontiers Media SA. This book was released on 2022-08-04 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impeller Discharge Flow Characteristics and Their Effect on Mixing Processes in Tanks written by S. W. Ruszkowski and published by . This book was released on 1992 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Engineering Fluid Mechanics written by Ron Darby and published by CRC Press. This book was released on 2016-11-30 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides readers with the most current, accurate, and practical fluid mechanics related applications that the practicing BS level engineer needs today in the chemical and related industries, in addition to a fundamental understanding of these applications based upon sound fundamental basic scientific principles. The emphasis remains on problem solving, and the new edition includes many more examples.
Download or read book CJChE written by and published by . This book was released on 2002-08 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bioprocess Engineering Principles written by Pauline M. Doran and published by Elsevier. This book was released on 1995-04-03 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: The emergence and refinement of techniques in molecular biology has changed our perceptions of medicine, agriculture and environmental management. Scientific breakthroughs in gene expression, protein engineering and cell fusion are being translated by a strengthening biotechnology industry into revolutionary new products and services. Many a student has been enticed by the promise of biotechnology and the excitement of being near the cutting edge of scientific advancement. However, graduates trained in molecular biology and cell manipulation soon realise that these techniques are only part of the picture. Reaping the full benefits of biotechnology requires manufacturing capability involving the large-scale processing of biological material. Increasingly, biotechnologists are being employed by companies to work in co-operation with chemical engineers to achieve pragmatic commercial goals. For many years aspects of biochemistry and molecular genetics have been included in chemical engineering curricula, yet there has been little attempt until recently to teach aspects of engineering applicable to process design to biotechnologists.This textbook is the first to present the principles of bioprocess engineering in a way that is accessible to biological scientists. Other texts on bioprocess engineering currently available assume that the reader already has engineering training. On the other hand, chemical engineering textbooks do not consider examples from bioprocessing, and are written almost exclusively with the petroleum and chemical industries in mind. This publication explains process analysis from an engineering point of view, but refers exclusively to the treatment of biological systems. Over 170 problems and worked examples encompass a wide range of applications, including recombinant cells, plant and animal cell cultures, immobilised catalysts as well as traditional fermentation systems.* * First book to present the principles of bioprocess engineering in a way that is accessible to biological scientists* Explains process analysis from an engineering point of view, but uses worked examples relating to biological systems* Comprehensive, single-authored* 170 problems and worked examples encompass a wide range of applications, involving recombinant plant and animal cell cultures, immobilized catalysts, and traditional fermentation systems* 13 chapters, organized according to engineering sub-disciplines, are groupled in four sections - Introduction, Material and Energy Balances, Physical Processes, and Reactions and Reactors* Each chapter includes a set of problems and exercises for the student, key references, and a list of suggestions for further reading* Includes useful appendices, detailing conversion factors, physical and chemical property data, steam tables, mathematical rules, and a list of symbols used* Suitable for course adoption - follows closely curricula used on most bioprocessing and process biotechnology courses at senior undergraduate and graduate levels.
Download or read book Mixing in the Process Industries written by A W NIENOW and published by Butterworth-Heinemann. This book was released on 1997-09-11 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is a valuable reference work for the student and the practising engineer in the chemical, pharmaceutical, minerals, food, plastics, paper and metallurgical industries. The second edition of this successful text has been thoroughly rewritten and updated. Based on the long running post-experience course produced by the University of Bradford, in association with the Institution of Chemical Engineers, it covers all aspects of mixing, from fundamentals through to design procedures in single and multi-phase systems. Experts from both industry and academia have contributed to this work giving both a theoretical practical approach. It covers dry and wet powders, single and two-phase liquids, solid/liquid and gas/liquid systems. The range of mixers available for such diverse duties is dealt with, including tumbler mixers for powders, mechanically agitated vessels, in-line continuous mixers and jet mixers. Coverage is given of the range of mixing objectives, varying from achieving product uniformity to obtaining optimum conditions for mass transfer and chemical reactions. This volume is a valuable reference work for the student and the practising engineer in the chemical, pharmaceutical, minerals, food, plastics, paper and metallurgical industries. The second edition of this successful text has been thoroughly rewritten and updated. Based on the long running post-experience course produced by the University of Bradford, in association with the Institution of Chemical Engineers, it covers all aspects of mixing, from fundamentals through to design procedures in single and multi-phase systems. Experts from both industry and academia have contributed to this work giving both a theoretical practical approach. It covers dry and wet powders, single and two-phase liquids, solid/liquid and gas/liquid systems. The range of mixers available for such diverse duties is dealt with, including tumbler mixers for powders, mechanically agitated vessels, in-line continuous mixers and jet mixers. Coverage is given of the range of mixing objectives, varying from achieving product uniformity to obtaining optimum conditions for mass transfer and chemical reactions.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2540 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Chemical Engineering Abstracts written by and published by . This book was released on 1986 with total page 954 pages. Available in PDF, EPUB and Kindle. Book excerpt:
