Bed diameter effect on the hydrodynamics of gas‐solid fluidized beds via radioactive particle tracking (RPT) technique

Efhaima, Abdelsalam; Al‐Dahhan, Muthanna H.

doi:10.1002/cjce.22757

Cited by 17 publications

(16 citation statements)

References 30 publications

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“…The green cluster above overlaps and shares many of the techniques with the blue cluster, as evidenced by the lines that represent co‐citation links. Particle size distribution (PSD), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier‐transform infrared spectroscopy (FTIR) are prominent in the cluster . The other techniques mostly relate to particle characterization (AAS, EDX, DSC, UPS) …”

Section: Introductionmentioning

confidence: 99%

Experimental methods in chemical engineering: Preface

Patience

2018

Can J Chem Eng

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Chemical engineering research encompasses a plethora of subjects ranging from nanoscale to climate change, from medicine to hazardous waste management, and from electronics and photonics to process intensification, manufacturing, and modelling. The 2017 AIChE meeting included 8000 oral presentations and posters with all these diverse topics. Here we identify experimental methods and instrumentation that straddle these subjects based on Can. J. Chem. Eng. articles published from 2016–2017. Temperature, pH, pressure, and flow rate are the physical properties most researchers report. We identified over 50 experimental techniques, reactor types, and modelling methodologies and show that articles with an experimental focus are more strongly linked than those that concentrate on hydrodynamic modelling and numerical simulation. Spectroscopy dominates instrumental techniques to characterize solids and catalyst properties and we classify 36 instruments according to what property they measure and the scale, nature of the phase, composition, and morphology. A bibliometric analysis grouped the physicochemical properties into three major research clusters centered around solid properties, liquid phase properties, and gas phase and aqueous phase properties. Articles in this special series describe the basic principles of one experimental method or instrument that appears frequently in the journal. Together with a short background, the articles highlight fields of application, assess the sources of error, detection thresholds, and uncertainty. This series provides chemical engineers with a concise, accessible reference guide to help identify and choose appropriate experimental techniques and instruments.

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Section: Introductionmentioning

confidence: 99%

Experimental methods in chemical engineering: Preface

Patience

2018

Can J Chem Eng

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“…Figure and Figure exhibit schematic and photographic images of the CT technique with a bubble column equipped with a bundle of vertical internals. The CT technique has been successfully applied to measure the phase holdup distribution in different multiphase flow reactors with various scale sizes at mReal such as 12 in (0.3 m) pebble bed reactor, 6 in (0.152 m) bubble column, 6 in (0.152 m) and 18 in (0.46 m) fluidized beds, and 3 in (0.076 m) and 6 in (0.152 m) spouted bed reactors . Details on the mechanical design, hardware, software, and operation of the CT technique have been discussed elsewhere by Varma .…”

Section: Gamma‐ray Computed Tomography (Ct)mentioning

confidence: 99%

Overcoming the gamma‐ray computed tomography data processing pitfalls for bubble column equipped with vertical internal tubes

et al. 2018

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This study identifies and addresses some major pitfalls that are involved in the visualization and quantification of the gas‐liquid distributions and their profiles in a bubble column with internals using the gamma‐ray computed tomography (CT) technique. Some of these pitfalls encountered in the scanning of bubble columns with internals are using an improper reference scan, and applying the same experimental scanning procedure and mathematical relationships for estimating the gas holdup in the column without internals to the column with internals. The experimental results revealed that the selection of the inappropriate reference scan for CT experiments would significantly affect the reconstructed linear attenuation coefficient values and consequently the gas holdup results. Additionally, the reconstructed linear attenuation values showed good agreement with theoretical values when considering air as reference scans. However, disagreement is observed when using the empty column with internals as a reference scan. Moreover, it was found that using the proper reference scan eliminated the errors not only for the reconstructed linear attenuation coefficients but also for the gas holdup values near the wall region. Furthermore, the CT technique was capable of capturing the small thickness (5 mm) of the wall for phantom and bubble columns as well as the internals when the air was used as the reference scan. Finally, a new methodology has been implemented to exclude the internals from the cross‐sectional images, and the azimuthally averaged gas holdup profiles to provide accurate and reliable results for comparison and validation purposes for the bubble column with internals.

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“…Ettehadieh et al 40 previously showed a centimeter‐sized jet makes the axial solid hold‐up uniform for Geldart D particles by increasing the solid diffusivity in this direction. However, since the radial solid diffusivity is constant for small bed diameters, 41 the bed remains almost uniform in the radial directions at all gas velocities. In this regime, the general patterns of solid hold‐up variations identified at U mf remain, but at proportionally lower solid hold‐up values as a result of introducing more fluidizing gas to the system.…”

Section: Resultsmentioning

confidence: 99%

Solid hold‐up measurement in a jet‐impactor assisted fluidized bed using gamma‐ray densitometry

et al. 2020

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A jet-impactor assisted-fluidized bed (JIAFB) for continuous de-agglomeration of nanopowder agglomerates was presented in previous work. Therein, a jet caused agglomerates to impinge up an impactor, where they would break. However, efficient impactor positioning will be dictated by particle momentum: the product of solid concentration and velocity must be highest. Herein, the variation of solid holdup was measured in a fluidized bed of Fe 2 O 3 nanoparticles using gamma-ray densitometry. Behaviour was compared under minimum fluidization and bubbling regimes, over a wide range of jet velocities (0-200 m s −1). A new line-decomposition approach allowed mapping local solid distribution across seven axial and five radial positions, tangibly demonstrating how increasing the gas velocity enhanced the fluidization quality by increasing axial solid diffusivity. Conversely, increasing jet velocity locally decreased solid holdup in the jet-affected zone, and brought about inhomogeneities.

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Bed diameter effect on the hydrodynamics of gas‐solid fluidized beds via radioactive particle tracking (RPT) technique

Cited by 17 publications

References 30 publications

Experimental methods in chemical engineering: Preface

Experimental methods in chemical engineering: Preface

Overcoming the gamma‐ray computed tomography data processing pitfalls for bubble column equipped with vertical internal tubes

Solid hold‐up measurement in a jet‐impactor assisted fluidized bed using gamma‐ray densitometry

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