Author: Yimin Peng
Publisher:
ISBN:
Category :
Languages : en
Pages : 360

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Book Description

Author: Tom Wytrwat
Publisher: Cuvillier Verlag
ISBN: 3736965710
Category : Technology & Engineering
Languages : en
Pages : 200

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Book Description
An in-depth experimental study of the fluid dynamics of turbulent fluidized beds with particles of Geldart’s Group B was carried out. For this purpose, fluidization behavior was investigated in different fluidized bed plants having diameters in the range of 0.05 m to 1 m. Pressure fluctuation analysis has been used as an identification tool for the turbulent fluidized bed regime. Different fluidization conditions have been investigated by variation of the fluidized bed properties, the bed material properties, and the gas properties. Based on the measured data, a correlation predicting the transition velocity from bubbling to turbulent fluidization is introduced. To investigate the local flow structure, capacitance probe measurements have been carried out. Using this measurement technique, local solids concentrations and properties of rising bubbles have been determined and analyzed. Finally, an empiric fluid dynamic model was developed using the local measurement data. It is mainly based on capacitance probe measurements and shows high accuracy in comparison to pressure data.

Author: Robert John Fiocco
Publisher:
ISBN:
Category : Fluidization
Languages : en
Pages : 0

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Book Description

Author: Tom Wytrwat
Publisher: SPE-Schriftenreihe 20
ISBN: 9783736975712
Category :
Languages : en
Pages : 200

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Book Description
An in-depth experimental study of the fluid dynamics of turbulent fluidized beds with particles of Geldart's Group B was carried out. For this purpose, fluidization behavior was investigated in different fluidized bed plants having diameters in the range of 0.05 m to 1 m. Pressure fluctuation analysis has been used as an identification tool for the turbulent fluidized bed regime. Different fluidization conditions have been investigated by variation of the fluidized bed properties, the bed material properties, and the gas properties. Based on the measured data, a correlation predicting the transition velocity from bubbling to turbulent fluidization is introduced. To investigate the local flow structure, capacitance probe measurements have been carried out. Using this measurement technique, local solids concentrations and properties of rising bubbles have been determined and analyzed. Finally, an empiric fluid dynamic model was developed using the local measurement data. It is mainly based on capacitance probe measurements and shows high accuracy in comparison to pressure data.

Author: Ramanujam Srinivasan
Publisher:
ISBN:
Category :
Languages : en
Pages : 122

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Book Description

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: David Thomas Falkowski
Publisher:
ISBN:
Category :
Languages : en
Pages : 322

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Book Description
The objective of this research was to evaluate different pressure probe techniques used to measure the pressure fluctuations in a fluidized bed, to determine the effect of bed parameters on the power spectrum, and to develop a second-order model that describes the spectrums. This work's motivation is to increase the knowledge of fluidized bed pressure phenomena and further the understanding of such fluidized bed research areas as similitude, chemical processes, and pressure diagnostic tools. Pressure fluctuations in a fluidized bed were measured with four pressure probe techniques (static-absolute, dynamic-absolute, static-differential, and dynamic-differential) to determine if differences existed. Testing showed that the absolute and differential techniques produced drastically different results under certain conditions. Comparison of dynamic and static techniques showed that their results were very similar in most situations. The probe arm position was an important testing parameter for all techniques. Pressure data at different bed heights, fluidization velocities, particle sizes/densities, and bed temperatures were taken to determine each parameter's effect on the spectrum. The relationship between bed height and dominant frequency agreed with the literature, but secondary peaks were a function of position in the bed and not affected by bed height. Through the Bode plot, the shifting of frequency peaks with fluidization velocity was documented as a continuous growth. Large-diameter, high-density particles (Group D) exhibited harmonic behavior, while small-diameter, low-density particles (Group A) yielded power spectrums with first-order characteristics. For temperatures up to 512°C, spectrums varied little when velocity ratios were kept nearly constant. Multiple-peak phenomena were associated with bubble coalescence, surface effects, and distributor jetting effects. A second-order model that describes the dominant peak's location and magnitude was developed. An equation for the natural frequency as a function of bed height was developed from experimental data and agreed with the literature. An equation for the damping ratio as a function of bed height was developed from experimental data and agreed with a new theoretical damping ratio presented here. Using these equations, the model was developed such that its output was a function of bed height, and the model qualitatively described the experimental spectrums adequately.

Author: Kevin Matthew Mandich
Publisher:
ISBN: 9781109703825
Category :
Languages : en
Pages : 212

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Book Description
The goal of this experimental work was to investigate methods of measuring important fluidization properties in a vertical, cold-flow, gas-fluidized bed to gain an understanding of the fluidization characteristics of the bed materials used. Quantities such as pressure drop across the bed, mean bed height, and minimum fluidization velocity were determined using non-invasive methods and were compared to fundamental fluidized bed theories to verify proper performance of the experiment. Granular temperature near the wall, a quantity of great interest in this system, was also determined using a non-invasive technique. An Acoustic Shot Noise probe, developed by Cody et al. (1996), was used to correlate the vibrational energy at the fluidized bed wall to the average particle velocity normal to this surface. By determining the mechanical transfer function of the confining tube, it was possible to obtain an estimate for the granular temperature near the wall by performing a spectral analysis of the wall acceleration time signal. Experimentally-determined values of pressure drop, mean bed height, and minimum fluidization velocity agreed well with the values predicted from theory. Average granular temperature values also agreed well with those obtained through similar means (Cody et al., 1996). The mean bed expansion ratio and average granular temperature results were compared with those obtained from a Computational Fluid Dynamics simulation (Didwania et al., to appear). Good agreement was observed between experiment and simulation, and special attention was given to the effects of changing key parameters in the model.

Author: K. S. Sutherland
Publisher:
ISBN:
Category : Bulk solids flow
Languages : en
Pages : 58

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Book Description
The development of a continuous method for determining changes in particle size and particle size distribution in fluid-bed systems has been studied experimentally. Differential pressure measurements were employed to study the effects of solid particle size on the behavior of gas-fluidized beds. The relevant bed properties are briefly described and a review given of previous work on the study of fluidized-bed quality. It is shown that, within certain limitations, measurements of bed quality can be used to indicate changes in particle size. Gas-bubble velocities, while increasing in proportion to the square root of bubble diameter, are also shown to be dependent on particle size, increasing as the particle size decreases.

Author: C. K. Gupta
Publisher: CRC Press
ISBN: 9781420049862
Category : Technology & Engineering
Languages : en
Pages : 526

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Book Description
Fluid Bed Technology in Materials Processing comprehensively covers the various aspects of fluidization engineering and presents an elaborate examination of the applications in a multitude of materials processing techniques. This singular resource discusses: All the basic aspects of fluidization essential to understand and learn about various techniques The range of industrial applications Several examples in extraction and process metallurgy Fluidization in nuclear engineering and nuclear fuel cycle with numerous examples Innovative techniques and several advanced concepts of fluidization engineering, including use and applications in materials processing as well as environmental and bio-engineering Pros and cons of various fluidization equipment and specialty of their applications, including several examples Design aspects and modeling Topics related to distributors effects and flow regimes A separate chapter outlines the importance of fluidization engineering in high temperature processing, including an analysis of the fundamental concepts and applications of high temperature fluidized bed furnaces for several advanced materials processing techniques. Presenting information usually not available in a single source, Fluid Bed Technology in Materials Processing serves Fluidization engineers Practicing engineers in process metallurgy, mineral engineering, and chemical metallurgy Researchers in the field of chemical, metallurgical, nuclear, biological, environmental engineering Energy engineering professionals High temperature scientists and engineers Students and professionals who adopt modeling of fluidization in their venture for design and scale up