Local Liquid Velocity Measurement of Trickle Bed Reactor Using Digitial Industrial X-ray Radiography

Local Liquid Velocity Measurement of Trickle Bed Reactor Using Digitial Industrial X-ray Radiography PDF Author: Khairul Anuar Mohd Salleh
Publisher:
ISBN:
Category : Chemical reactors
Languages : en
Pages : 107

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Book Description
"Trickle Bed Reactors (TBRs) are fixed beds of particles in which both liquid and gas flow concurrently downward. They are widely used to produce not only fuels but also lubrication products. The measurement and the knowledge of local liquid velocities (VLL) in TBRs is less which is essential for advancing the understanding of its hydrodynamics and for validation computational fluid dynamics (CFD). Therefore, this work focused on developing a new, non-invasive, statistically reliable technique that can be used to measure local liquid velocity (V[subscript LL]) in two-dimensions (2-D). This is performed by combining Digital Industrial X-ray Radiography (DIR) and Particle Tracking Velocimetry (PTV) techniques. This work also make possible the development of three-dimensional (3-D) V[subscript LL] measurements that can be taken in TBRs. Measurements taken through both the combined and the novel technique, once validated, were found to be comparable to another technique (a two-point fiber optical probe) currently being developed at Missouri University of Science and Technology. The results from this study indicate that, for a gas-liquid-solid type bed, the measured V[subscript LL] can have a maximum range that is between 35 and 51 times that of its superficial liquid velocity (V[subscript SL]). Without the existence of gas, the measured V[subscript LL] can have a maximum range that is between 4 and 4.7 times that of its V[subscript SL]. At a higher V[subscript SL], the particle tracer was greatly distributed and became carried away by a high liquid flow rate. Neither the variance nor the range of measured V[subscript LL] varied for any of the replications, confirming the reproducibility of the experimental measurements used, regardless of the V[subscript SL]. The liquid's movement inside the pore was consistent with findings from previous studies that used various techniques"--Abstract, page iii.

Local Liquid Velocity Measurement of Trickle Bed Reactor Using Digitial Industrial X-ray Radiography

Local Liquid Velocity Measurement of Trickle Bed Reactor Using Digitial Industrial X-ray Radiography PDF Author: Khairul Anuar Mohd Salleh
Publisher:
ISBN:
Category : Chemical reactors
Languages : en
Pages : 107

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Book Description
"Trickle Bed Reactors (TBRs) are fixed beds of particles in which both liquid and gas flow concurrently downward. They are widely used to produce not only fuels but also lubrication products. The measurement and the knowledge of local liquid velocities (VLL) in TBRs is less which is essential for advancing the understanding of its hydrodynamics and for validation computational fluid dynamics (CFD). Therefore, this work focused on developing a new, non-invasive, statistically reliable technique that can be used to measure local liquid velocity (V[subscript LL]) in two-dimensions (2-D). This is performed by combining Digital Industrial X-ray Radiography (DIR) and Particle Tracking Velocimetry (PTV) techniques. This work also make possible the development of three-dimensional (3-D) V[subscript LL] measurements that can be taken in TBRs. Measurements taken through both the combined and the novel technique, once validated, were found to be comparable to another technique (a two-point fiber optical probe) currently being developed at Missouri University of Science and Technology. The results from this study indicate that, for a gas-liquid-solid type bed, the measured V[subscript LL] can have a maximum range that is between 35 and 51 times that of its superficial liquid velocity (V[subscript SL]). Without the existence of gas, the measured V[subscript LL] can have a maximum range that is between 4 and 4.7 times that of its V[subscript SL]. At a higher V[subscript SL], the particle tracer was greatly distributed and became carried away by a high liquid flow rate. Neither the variance nor the range of measured V[subscript LL] varied for any of the replications, confirming the reproducibility of the experimental measurements used, regardless of the V[subscript SL]. The liquid's movement inside the pore was consistent with findings from previous studies that used various techniques"--Abstract, page iii.

Investigation of Local Velocities and Phase Holdups, and Flow Regimes and Maldistribution Identification in a Trickle Bed Reactor

Investigation of Local Velocities and Phase Holdups, and Flow Regimes and Maldistribution Identification in a Trickle Bed Reactor PDF Author: Mohd Fitri Bin Abdul Rahman
Publisher:
ISBN:
Category : Chemical reactors
Languages : en
Pages : 130

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Book Description
"Trickle bed reactors are packed beds of catalyst on which gas and liquid reactants flow concurrently downward. In this work, the experimental work was carried out in 0.14 m diameter Plexiglas column using air-water system flowing over a packed bed of 3 mm glass bead particles. The local liquid and gas velocities, phase saturation and their time series have been investigated for the first time by developing, validating, and implementing a new two-tip optical fiber probe technique. It was found the radially and axially the liquid and gas velocities and their saturation vary and they also vary with times. In various locations, due to non-uniform distribution of the flowing phases, there are windows of time where the gas phase does not pass through that location where the optical fiber probe was put at. The non-invasive gamma-ray densitometry (GRD) technique has been implemented for the first time in trickle bed reactor as in online monitoring technique to identify flow regime, gross maldistribution and liquid distribution. The GRD technique was able to identify trickle and pulse flow regime and their transition. The findings have been consistent with what have been reported in the literature. The measurement of these techniques was conducted at various axial and radial positions with the superficial liquid velocity varies in the range 0.004 - 0.016 m/s and the superficial gas velocity varies in the range of 0.03-0.27 m/s covering trickling and pulsing flow regime. The results obtained confirm that these techniques can be used with fidelity for measurements and the studies mentioned above and can be employed in various sizes of reactor operated at industrial conditions including harsh conditions of corrosion materials, high pressure, and high temperatures"--Abstract, page iv.

Solid-liquid Mass Transfer in Trickle Bed Reactors

Solid-liquid Mass Transfer in Trickle Bed Reactors PDF Author: Rita Joubert
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Hydrodynamic multiplicity in the trickle flow, or low interaction, regime is a well documented phenomenon. Multiple hydrodynamic states are often presented in the form of hysteresis loops where the hydrodynamic parameter studied are shown as a function of the operating history of the bed, i.e. liquid and gas flow rates. In extreme cases the lower leg, representing an increase in liquid flow rate on a pre-wetted and drained bed, is commonly referred to as the Levec mode. The upper extreme, referred to as the Kan-liquid mode, represents a decrease in liquid flow rate after operation in the high interaction regime. The many reported studies investigating liquid-solid mass transfer in trickle beds have generally used either the dissolution or electrochemical techniques. Numerous researchers have used their data to develop correlations predicting solid-liquid mass transfer coefficients. Most of these studies do not specify the multiplicity mode of operation. Only two studies (Sims et al. (1993) and Van der Merwe, Nicol & Al-Dahhan (2008)) use both the Levec and Kan-liquid operating modes. Both of these studies suggest that solid-liquid mass transfer also exhibit multiplicity behaviour although the trends suggested or speculated differ from each other. Sims et al. (1993) found that a Kan-liquid operated bed will outperform a Levec operated bed: however in contrast to this Van der Merwe et al. (2008) speculated that a Levec operated bed is better suited for liquid limited reactions due to enhanced liquid-solid mass transfer in the Levec mode as a result of faster interstitial velocity. This study showed that solid-liquid mass transfer coefficients, measured with both the dissolution and electrochemical technique, show multiplicity behaviour. Two distinct operating regions were found, which corresponds to the Levec and Kan-liquid modes. Measurements taken using the electrochemical technique yielded solid-liquid mass transfer coefficients larger than those measured using the dissolution method. The experimental results agree with the trend found by Sims et al. (1993) but the mass transfer coefficients in this study were significantly lower. Additionally it was shown that the difference in mass transfer coefficients, in the two modes, cannot be explained by merely compensating for the differences in wetting efficiency and interstitial velocity, suggesting that the Levec mode has a larger percentage of stagnant or poorly irrigated zones. It was also shown that mass transfer coefficients measured at the top of the column is higher than those measured at the bottom, suggesting that the flow structure is changing as a function of axial length. Lastly, with regards to electrochemical measurements of liquid-solid mass transfer, it was shown that measurements using a single particle electrode compared well to that of a multiple packing electrode.

Industrial Process Gamma Tomography

Industrial Process Gamma Tomography PDF Author: International Atomic Energy Agency
Publisher:
ISBN:
Category : Gamma radiography
Languages : en
Pages : 153

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Book Description


Industrial Catalytic Processes for Fine and Specialty Chemicals

Industrial Catalytic Processes for Fine and Specialty Chemicals PDF Author: Sunil S Joshi
Publisher: Elsevier
ISBN: 0128016701
Category : Technology & Engineering
Languages : en
Pages : 784

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Book Description
Industrial Catalytic Processes for Fine and Specialty Chemicals provides a comprehensive methodology and state-of-the art toolbox for industrial catalysis. The book begins by introducing the reader to the interesting, challenging, and important field of catalysis and catalytic processes. The fundamentals of catalysis and catalytic processes are fully covered before delving into the important industrial applications of catalysis and catalytic processes, with an emphasis on green and sustainable technologies. Several case studies illustrate new and sustainable ways of designing catalysts and catalytic processes. The intended audience of the book includes researchers in academia and industry, as well as chemical engineers, process development chemists, and technologists working in chemical industries and industrial research laboratories. - Discusses the fundamentals of catalytic processes, catalyst preparation and characterization, and reaction engineering - Outlines the homogeneous catalytic processes as they apply to specialty chemicals - Introduces industrial catalysis and catalytic processes for fine chemicals - Includes a number of case studies to demonstrate the various processes and methods for designing green catalysts

Flash Radiography

Flash Radiography PDF Author: Francis Jamet
Publisher: Elsevier Science & Technology
ISBN:
Category : Science
Languages : en
Pages : 212

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Book Description


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.

Industrial Tomography

Industrial Tomography PDF Author: Mi Wang
Publisher: Woodhead Publishing
ISBN: 0128233079
Category : Technology & Engineering
Languages : en
Pages : 924

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Book Description
Industrial Tomography: Systems and Applications, Second Edition thoroughly explores the important techniques of industrial tomography, also discusses image reconstruction, systems, and applications. This book presents complex processes, including the way three-dimensional imaging is used to create multiple cross-sections, and how computer software helps monitor flows, filtering, mixing, drying processes, and chemical reactions inside vessels and pipelines. This book is suitable for materials scientists and engineers and applied physicists working in the photonics and optoelectronics industry or in the applications industries. - Provides a comprehensive discussion on the different formats of tomography, including advances in visualization and data fusion - Includes an excellent overview of image reconstruction using a wide range of applications - Presents a comprehensive discussion of tomography systems and their applications in a wide variety of industrial processes

Advances in Clean Energy Technologies

Advances in Clean Energy Technologies PDF Author: Prashant V. Baredar
Publisher: Springer Nature
ISBN: 9811602352
Category : Business & Economics
Languages : en
Pages : 1130

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Book Description
This book presents select proceedings of the international conference on Innovations in Clean Energy Technologies (ICET 2020) and examines a range of durable, energy efficient and next-generation smart green technologies for sustainable future by reflecting on the trends, advances and development taking place all across the globe. The topics covered include smart technologies based product, energy efficient systems, solar and wind energy, carbon sequestration, green transportation, green buildings, energy material, biomass energy, smart cites, hydro power, bio-energy and fuel cell. The book also discusses various performance attributes of these clean energy technologies and their workability and carbon footprint. The book will be a valuable reference for beginners, researchers and professionals interested in clean energy technologies.

A Dictionary of Mining, Mineral, and Related Terms

A Dictionary of Mining, Mineral, and Related Terms PDF Author: United States. Bureau of Mines
Publisher:
ISBN:
Category : Mineral industries
Languages : en
Pages : 1284

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Book Description
Includes about 55,000 individual mining and mineral industry term entries with about 150,000 definitions under these terms.