Bubble size and bubble rise velocity estimation by means of electrical capacitance tomography within gas-solids fluidized beds

Xiaoxu Li, Artur J. Jaworski, Xiaoan Mao

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5 Citations (Scopus)

Abstract

Electrical capacitance tomography (ECT) has been developed as a non-invasive and non-intrusive measurement technique to investigate the internal hydrodynamic characteristics of gas-solids systems in fluidized beds. This paper describes an investigation, in which a customized twin-plane ECT sensor was designed and constructed to study the fluid flow processes within a bench-scale gas-solids fluidized bed. A detailed calibration process was conducted using hollow plastic balls of different diameters to derive the reference grey level cut-off values for determining the bubble diameter. In addition, numerical simulations were carried out to investigate the plastic ball wall effect on measured capacitance values. Bubble diameters were estimated by means of the individual reference cut-off values and their linear and second-order fitted curves. Linear back-projection (LBP) and iterative LBP image reconstruction algorithms were compared with respect to estimating the bubble diameter. A number of approaches were investigated to estimate the bubble rise velocity including three methods based on cross-correlation techniques and the detailed signal analysis. Bubble diameters were also obtained using a new approach based on “back-calculation” of the bubble rise velocity through widely accepted empirical correlations from the existing literature.
LanguageEnglish
Pages226-240
Number of pages15
JournalMeasurement: Journal of the International Measurement Confederation
Volume117
Early online date13 Dec 2017
DOIs
Publication statusPublished - 1 Mar 2018

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Fluidized beds
Tomography
beds
Capacitance
bubbles
tomography
capacitance
Gases
gases
Plastics
Signal analysis
Image reconstruction
balls
Flow of fluids
cut-off
plastics
Hydrodynamics
projection
nonintrusive measurement
Calibration

Cite this

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title = "Bubble size and bubble rise velocity estimation by means of electrical capacitance tomography within gas-solids fluidized beds",
abstract = "Electrical capacitance tomography (ECT) has been developed as a non-invasive and non-intrusive measurement technique to investigate the internal hydrodynamic characteristics of gas-solids systems in fluidized beds. This paper describes an investigation, in which a customized twin-plane ECT sensor was designed and constructed to study the fluid flow processes within a bench-scale gas-solids fluidized bed. A detailed calibration process was conducted using hollow plastic balls of different diameters to derive the reference grey level cut-off values for determining the bubble diameter. In addition, numerical simulations were carried out to investigate the plastic ball wall effect on measured capacitance values. Bubble diameters were estimated by means of the individual reference cut-off values and their linear and second-order fitted curves. Linear back-projection (LBP) and iterative LBP image reconstruction algorithms were compared with respect to estimating the bubble diameter. A number of approaches were investigated to estimate the bubble rise velocity including three methods based on cross-correlation techniques and the detailed signal analysis. Bubble diameters were also obtained using a new approach based on “back-calculation” of the bubble rise velocity through widely accepted empirical correlations from the existing literature.",
keywords = "bubble diameter, bubble rise velocity, electrical capacitance tomography, gas-solids fluidized beds, numerical simulation",
author = "Xiaoxu Li and Jaworski, {Artur J.} and Xiaoan Mao",
year = "2018",
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doi = "10.1016/j.measurement.2017.12.017",
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TY - JOUR

T1 - Bubble size and bubble rise velocity estimation by means of electrical capacitance tomography within gas-solids fluidized beds

AU - Li, Xiaoxu

AU - Jaworski, Artur J.

AU - Mao, Xiaoan

PY - 2018/3/1

Y1 - 2018/3/1

N2 - Electrical capacitance tomography (ECT) has been developed as a non-invasive and non-intrusive measurement technique to investigate the internal hydrodynamic characteristics of gas-solids systems in fluidized beds. This paper describes an investigation, in which a customized twin-plane ECT sensor was designed and constructed to study the fluid flow processes within a bench-scale gas-solids fluidized bed. A detailed calibration process was conducted using hollow plastic balls of different diameters to derive the reference grey level cut-off values for determining the bubble diameter. In addition, numerical simulations were carried out to investigate the plastic ball wall effect on measured capacitance values. Bubble diameters were estimated by means of the individual reference cut-off values and their linear and second-order fitted curves. Linear back-projection (LBP) and iterative LBP image reconstruction algorithms were compared with respect to estimating the bubble diameter. A number of approaches were investigated to estimate the bubble rise velocity including three methods based on cross-correlation techniques and the detailed signal analysis. Bubble diameters were also obtained using a new approach based on “back-calculation” of the bubble rise velocity through widely accepted empirical correlations from the existing literature.

AB - Electrical capacitance tomography (ECT) has been developed as a non-invasive and non-intrusive measurement technique to investigate the internal hydrodynamic characteristics of gas-solids systems in fluidized beds. This paper describes an investigation, in which a customized twin-plane ECT sensor was designed and constructed to study the fluid flow processes within a bench-scale gas-solids fluidized bed. A detailed calibration process was conducted using hollow plastic balls of different diameters to derive the reference grey level cut-off values for determining the bubble diameter. In addition, numerical simulations were carried out to investigate the plastic ball wall effect on measured capacitance values. Bubble diameters were estimated by means of the individual reference cut-off values and their linear and second-order fitted curves. Linear back-projection (LBP) and iterative LBP image reconstruction algorithms were compared with respect to estimating the bubble diameter. A number of approaches were investigated to estimate the bubble rise velocity including three methods based on cross-correlation techniques and the detailed signal analysis. Bubble diameters were also obtained using a new approach based on “back-calculation” of the bubble rise velocity through widely accepted empirical correlations from the existing literature.

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KW - bubble rise velocity

KW - electrical capacitance tomography

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KW - numerical simulation

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