This book covers the rich phenomenology exhibited by fine powders when they are fluidized by a gas flow. Fine powder cohesiveness leads to poor flowability, clumping, difficulty in fluidizing, irregular avalanching behavior, etc. Despite all the inconveniences, fine powder processes pervade the chemical, pharmaceutical, agricultural and mining industries among others. The author in this book analyzes the mechanism by which interparticle adhesive forces are reduced by means of surface additives. Different techniques have been developed in the last years to assist fluidization by helping the gas flow to mobilize and break cohesive aggregates, which help to homogenize fluidization. As reviewed in this book, the use of these techniques may have a relevant impact on novel processes based on fluidized beds of fine powder and with relevant applications on leading edge technologies such as Atomic Layer Deposition on nanoparticles and CO2 capture by gas-fluidized beds of adsorbent powders. The study of fluidized beds has a marked interdisciplinary character. This book is thus intended for academic and industrial researchers in applied physics, mechanical, chemical, and environmental engineering, who are interested in the special characteristics of fine powders.

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.

Fine powders are not fluidized as readily as coarse powders. Because of their adhesive properties, fine powders tend to form channels, which decrease the effectiveness of contact between particle and gas. Pulse fluidization overcomes the deficiencies of conventional fluidization by attenuating the formation of channels and slugs. The present study compares the pressure fluctuations of conventional and pulse fluidized beds of a fine powder. The results indicate that pulse fluidization improves contact efficiency by increasing the pressure drop and the apparent viscosity of the bed. The "induced fluctuations" of a pulse fluidized bed contain high-frequency components, indicating the presence of small, dispensed bubbles; the "free fluctuations" of a conventional bed contain only low-frequency components, indicating large, coalesced bubbles. By attenuating the formation of channels, stability is also approved, especially at low gas velocities.

flour, potato starch, cracking catalyst, sand, and gravel, one will probably agree that the first four materials definitely are powders and the last one certainly is not. Whether one would call sand a powder probably depends on the partiele size and on personal Vlews. When the astronaut Neil Armstrong returned to the Earth from his trip on the surface of the Moon, he stated: 'The surface is fine and powdery. I can kick it up loosely with my toe. It does adhere in fine layers like powdered charcoal to the sole and inside of my boots. I only go in a small fraction of an inch, but I can see the footprints of my boots and the treads in the fine sandy partieles. ' These words elearly show that the behaviour of powders de pends on the circumstances. In wh at respects are those on the Moon different from those on the Earth? (1) The gravitational force on the surface of the Moon is only one-sixth of that on the Earth. (2) There is no gas on the Moon. The latter aspect means that any water brought there would evaporate and disappear immediately, hence powders on the Moon will always be perfect1y dry so that cohesion between the separate partieles due to liquid bridges will be zero.

This work is concerned with the effect of vessel geometry on the hydrodynamics of fluidisation of a bed of milled iron oxide. The effect of going from a cold model representative of a typical pilot plant reactor to one simulating a semi-commercial unit is quantified, and various reactor internal configurations on the latter are evaluated.

· Explains operation and scientific fundamentals of circulating fluidized bed (CFB) boilers · Outlines practical issues in industrial use · Teaches how to optimize design for maximum reliability and efficiency · Discusses operating and maintenance issues and how to troubleshoot them This book provides practicing engineers and students with insight into the design and operation of circulating fluidized bed (CFB) boilers through a combination of theoretical concepts and practical experience. An emphasis on combustion, hydrodynamics, heat transfer, and material issues illustrates these concepts with numerous examples from actual operating plants. The relevance of design and feed-stock parameters to the operation of a CFB boiler are also examined, along with their impacts on designs of mechanical components, including cyclones, air distributor grids, and solid recycle systems. This versatile resource explains how fluidized bed equipment works and how the basic principles of thermodynamics and fluid mechanics influence design, while providing insight into planning new projects, troubleshooting existing equipment, and appreciating the capabilities and limitations of the process. From hydrodynamics to construction and maintenance, the author covers all of the essential information needed to understand, design, operate, and maintain a complete fluidized bed system. It is a must for clean coal technology as well as for biomass power generation.

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.

A concise and clear treatment of the fundamentals of fluidization, with a view to its applications in the process and energy industries.

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.