Download or read book Gas solid Fluidized Bed Reactors Scale up Flow Regimes Identification and Hydrodynamics written by Faraj Muftah Zaid and published by . This book was released on 2013 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This research studied the scale-up, flow regimes identification and hydrodynamics of fluidized beds using 6-inch and 18- inch diameter columns and different particles. One of the objectives was to advance the scale-up of gas-solid fluidized bed reactors by developing a new mechanistic methodology for hydrodynamic similarity based on matching the radial or diameter profile of gas phase holdup, since gas dynamics dictate the hydrodynamics of these reactors. This has been successfully achieved. However, the literature reported scale-up methodology based on matching selected dimensionless groups was examined and it was found that it was not easy to match the dimensionless groups and hence, there was some deviation in the hydrodynamics of the studied two different fluidized beds. A new technique based on gamma ray densitometry (GRD) was successfully developed and utilized to on-line monitor the implementation of scale-up, to identify the flow regime, and to measure the radial or diameter profiles of gas and solids holdups. CFD has been demonstrated as a valuable tool to enable the implementation of the newly developed scale-up methodology based on finding the conditions that provide similar or closer radial profile or cross sectional distribution of the gas holdup. As gas velocity increases, solids holdup in the center region of the column decreases in the fully developed region of both 6 inch and 18 inch diameter columns. Solids holdup increased with the increase in the particles size and density. Upflowing particles velocity increased with the gas velocity and became steeper at high superficial gas velocity at all axial heights where the center line velocity became higher than that in the wall region. Smaller particles size and lower density gave larger upflowing particles velocity. Minimum fluidization velocity and transition velocity from bubbly to chum turbulent flow regimes were found to be lower in 18 inch diameter column compared to those obtained in 6 inch diameter column. Also the absolute fluctuation of upflowing particles velocity multiplied by solids holdups as one of the terms for solids mass flux estimation was found to be larger in 18-inch diameter column than that in 6-inch diameter column using same particles size and density"--Abstract, leaf iii.
Download or read book Scaleup and Hydrodynamics Study of Gas solid Spouted Beds written by Shreekanta Basavaraj Aradhya and published by . This book was released on 2013 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A thorough understanding of the complex flow structure of gas-solid spouted bed is crucial for design, scale-up and performance. Advanced gas-solid optical probes were developed and used to evaluate different hydrodynamic parameters of spouted beds. These optical probes measure solids concentration, velocity and their time series fluctuations. Since solids concentration needs to be converted to solids holdup through calibration, for meaningful interpretation of results, a novel calibration method was proposed (which is inexpensive and reliable compared to the current reported methods) and validated in the present study. The reported dimensionless groups approach of spouted bed scale-up was assessed and was found that the two different spouted beds were not hydrodynamically similar. Hence, a new scale-up methodology based on maintaining similar or close radial profiles of gas holdup was proposed, assessed and validated. CFD was used after it was validated as an enabling tool to facilitate the implementation of the newly developed scale-up methodology by identifying the new conditions for maintaining radial profiles of gas holdup while scaling up. It can also be implemented to quantify the effect of various variables on their hydrodynamic parameters. Gamma Ray Densitometry (GRD), a non-invasive radioisotope based technique, was developed and demonstrated to montior [sic]on-line the conditions for the scale-up, flow regime and spouted beds operation. The solids holdup in spout region increases with axial height due to movement of solids from the annulus region. However, solids velocity in the spout region decreases with axial height. In the annulus region the solids move downward as a loose packed bed and the solids velocity and holdup do not change with axial height. Using factorial design of experiments it was found that solids density, static bed height, particle diameter, superficial gas velocity and gas inlet diameter had significant effect on the identification of spout diameter. Flow regimes in spouted bed were determined with the help of optical probes, pressure transducers and GRD. It was found that the range of stable spouting regime is higher in 0.152 m beds and the range of stable spouting decreases in the 0.076 m beds. The newly developed non-invasive radioisotope technique (GRD) was able to successfully identify different flow regimes and their transition velocities besides scale-up conditions and operation"--Abstract, page iii.
Download or read book Hydrodynamic of a Co current Gas Liquid Upflow in a Moving Packed Bed Reactor with Porous Catalysts written by Ali Jabbar Toukan and published by . This book was released on 2016 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In this study, the hydrodynamic, i.e. flow regime identification, line average liquid holdup, and the internal liquid holdup of a co-current moving packed bed reactor were studied. For the sake of hydrodynamics study, moving bed reactor is investigated as two-phase upflow packed bed reactor. Scaled down configuration was used to simulate of the moving bed reactors utilized in the industrial process. First, line average liquid holdup is measured with different geometrical configurations covering empty, dry, wet, and packed column under flowrates operation conditions. A new methodology has been developed to determine the line average liquid holdup for a porous catalyst. Second, flow regime is identified by variation of superficial gas velocity at constant liquid superficial velocity. The experiments were carried out in an 11 - inch inner diameter Plexiglas column using the air-water system, at superficial gas velocities in the range of 0.6 to 7.7 cm/s and at a constant liquid superficial velocity of 0.017 cm/s. Gamma ray densitometry (GRD) technique was used to obtain the line average liquid holdup and to identify the flow regime at different axial and radial positions along the column. The obtained results showed that the flow regimes are bubble flow and pulse flow regimes with a transition flow in-between under the operation conditions used. The result showed that the liquid holdup decreased as the superficial gas velocity increased. It was also found that the liquid holdup radial distribution was not uniform. These kinds of information are essential to improve the performance of the reactor"--Abstract, page iv.
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 Hydrodynamics of Fluidized Bed Reactors for Wastewater Treatment written by Boris M. Khudenko and published by . This book was released on 1982 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mints' model adequately describes ideal static (nonvariable input parameters) liquid-solid fluidization. This model has a good theoretical basis and describes bed expansion relationships for a wide range of experimental data. This model has been verified for materials with low densities relative to the fluidizing liquid. The lower limit for the validity of Mints' model occurs at a Reynolds number, re, of approximately 1. It is suggested that below this value the state of fluidization does not exist, however, the regime of flow may correspond to an expanded bed. Deviations from the idealized model occur at low and high Reynolds numbers. These deviations correspond to unstable flow regimes, exhibited in the form of channeling and boiling. The loss of stability at high Reynolds numbers is due to the inherent instability of the layered structure of liquid-solid fluidized beds.
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 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 Computational Flow Modeling for Chemical Reactor Engineering written by Vivek V. Ranade and published by Academic Press. This book was released on 2002 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Chaotic Hydrodynamics of Large and Small Circulating Fluidized Beds written by Robert Cornelis Zijerveld and published by . This book was released on 1998 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrodynamic Aspects of a Three phase Fluidized Bed Reactor written by Michael John Bly and published by . This book was released on 1992 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Interconnected Fluidized Bed Reactor for Gas solids Regenerative Processes written by Onno Cornelis Snip and published by . This book was released on 1997 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 1088 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.
Download or read book Multiphase Catalytic Reactors written by Zeynep Ilsen Önsan and published by John Wiley & Sons. This book was released on 2016-07-05 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a holistic approach to multiphase catalytic reactors from their modeling and design to their applications in industrial manufacturing of chemicals Covers theoretical aspects and examples of fixed-bed, fluidized-bed, trickle-bed, slurry, monolith and microchannel reactors Includes chapters covering experimental techniques and practical guidelines for lab-scale testing of multiphase reactors Includes mathematical content focused on design equations and empirical relationships characterizing different multiphase reactor types together with an assortment of computational tools Involves detailed coverage of multiphase reactor applications such as Fischer-Tropsch synthesis, fuel processing for fuel cells, hydrotreating of oil fractions and biofuels processing
Download or read book Hydrodynamics of Gas Liquid Reactors written by Barry Azzopardi and published by John Wiley & Sons. This book was released on 2011-05-12 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design of chemical reactors and their safety are as critical to the success of a chemical process as the actual chemistry taking place within the reactor. This book provides a comprehensive overview of the practical aspects of multiphase reactor design and operation with an emphasis on safety and clean technology. It considers not only standard operation conditions, but also the problems of runaway reaction conditions and protection against ensuing over-pressure. Hydrodynamics of Multiphase Reactors addresses both practical and theoretical aspects of this topic. Initial chapters discuss various different types of gas/liquid reactors from a practical viewpoint, and later chapters focus on the modelling of multiphase systems and computational methods for reactor design and problem solving. The material is written by experts in their specific fields and will include chapters on the following topics: Multiphase flow, Bubble columns, Sparged stirred vessels, Macroscale modelling, Microscale modelling, Runaway conditions, Behaviour of vessel contents, Choked flow, Measurement techniques.
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 873 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.
Download or read book Hydrodynamics of Foaming Trickle Bed Reactors written by Sodhi Vijay and published by LAP Lambert Academic Publishing. This book was released on 2014-01 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas-liquid-solid (catalysts) reactive systems encountered in trickle bed reactors are common in chemical engineering related cocurrent gas and liquid downflow systems. Among these processes relying on trickle beds, hydrodynamics of foaming systems are less prominently explored subject despite the formation of foaming is very often in the petroleum industries. This study's aim was to demonstrate experimentally the effects of liquid and gas flow velocities, and liquid surface tension for key phenomenon like regime transition change, two-phase pressure drop, dynamic liquid hold-up and liquid axial dispersion. More than 240 experimental points for the trickle flow (GCF) and foaming pulsing flow (PF/FPF) regime were obtained for present study, revealed significant evaluations for sustainable process design especially for industrial applications.
Download or read book Pulsing flow Regime in Trickle bed Reactors written by Benjamin A. Wilhite and published by . This book was released on 2002 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
