Investigation of bubble behaviour in a gas-solid fluidized bed by means of a twin-plane ECT sensor

Xiaoxu Li, AJ Jaworski, Xiaoan Mao

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Fluidized beds are used extensively in chemical engineering applications, such as food processing, combustion, gasification processes and pharmaceutical industry. However, due to their complex fluid mechanical characteristics (for example bubble size and bubble velocity), conventional measuring techniques do not permit a sufficient understanding. Electrical Capacitance Tomography (ECT) has been developed over the last few decades as a non-invasive measurement technique and applied to study gas-solids fluidized beds. Although many researchers investigated relationships governing bubble sizes, the influence of cut-off value (a grey level value distinguishing gas and solid phases) of bubble boundary on the bubble size estimation is still not fully understood. A twin-plane ECT sensor with 10 mm-long measuring electrodes has been designed and fabricated to study the single bubbling regime in a gas-solids model fluidized bed. To investigate the influence of the cut-off value on bubble size estimation, different diameter hollow plastic balls have been imaged while the bed is at packed bed state. Appropriate MATLAB code has been developed to extract the cut-off values of the boundary for these plastic balls. Based on the cut-off values, bubble size within single bubbling regime has been estimated by LBP and iterative LBP image reconstruction algorithms.

Finally, estimated bubble size has been compared and analysed with existing bubble size estimation correlations. Future work will focus on the effect of different reconstruction algorithms and permittivity models on bubble size estimation to get more comprehensive understanding of bubble behaviour to examine the capability of ECT at estimating single bubble size within fluidized bed.
Original languageEnglish
Title of host publicationProceedings of the 8th World Congress on Industrial Process Tomography, (Iguassu Falls, Brazil: 26-29 September 2016)
PublisherInternational Society for Industrial Process Tomography
ISBN (Electronic)9780853163497
Publication statusPublished - 2016
Externally publishedYes
Event8th World Congress on Industrial Process Tomography - Rafain Palace Hotel & Convention Center, Iguassu Falls, Brazil
Duration: 26 Sep 201629 Sep 2016
Conference number: 8
http://www.isipt.org/wcipt8 (Link to Conference Website )

Publication series

NameWorld Congress on Industrial Process Tomography
PublisherInternational Society for Industrial Process Tomography
ISSN (Electronic)2309-3870

Conference

Conference8th World Congress on Industrial Process Tomography
Abbreviated titleWCIPT8
CountryBrazil
CityIguassu Falls
Period26/09/1629/09/16
Internet address

Fingerprint

Fluidized beds
Tomography
Capacitance
Sensors
Gases
Plastics
Food processing
Packed beds
Chemical engineering
Image reconstruction
Gasification
Drug products
MATLAB
Permittivity
Electrodes
Fluids
Industry

Cite this

Li, X., Jaworski, AJ., & Mao, X. (2016). Investigation of bubble behaviour in a gas-solid fluidized bed by means of a twin-plane ECT sensor. In Proceedings of the 8th World Congress on Industrial Process Tomography, (Iguassu Falls, Brazil: 26-29 September 2016) [B4] (World Congress on Industrial Process Tomography). International Society for Industrial Process Tomography.
Li, Xiaoxu ; Jaworski, AJ ; Mao, Xiaoan. / Investigation of bubble behaviour in a gas-solid fluidized bed by means of a twin-plane ECT sensor. Proceedings of the 8th World Congress on Industrial Process Tomography, (Iguassu Falls, Brazil: 26-29 September 2016). International Society for Industrial Process Tomography, 2016. (World Congress on Industrial Process Tomography).
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title = "Investigation of bubble behaviour in a gas-solid fluidized bed by means of a twin-plane ECT sensor",
abstract = "Fluidized beds are used extensively in chemical engineering applications, such as food processing, combustion, gasification processes and pharmaceutical industry. However, due to their complex fluid mechanical characteristics (for example bubble size and bubble velocity), conventional measuring techniques do not permit a sufficient understanding. Electrical Capacitance Tomography (ECT) has been developed over the last few decades as a non-invasive measurement technique and applied to study gas-solids fluidized beds. Although many researchers investigated relationships governing bubble sizes, the influence of cut-off value (a grey level value distinguishing gas and solid phases) of bubble boundary on the bubble size estimation is still not fully understood. A twin-plane ECT sensor with 10 mm-long measuring electrodes has been designed and fabricated to study the single bubbling regime in a gas-solids model fluidized bed. To investigate the influence of the cut-off value on bubble size estimation, different diameter hollow plastic balls have been imaged while the bed is at packed bed state. Appropriate MATLAB code has been developed to extract the cut-off values of the boundary for these plastic balls. Based on the cut-off values, bubble size within single bubbling regime has been estimated by LBP and iterative LBP image reconstruction algorithms. Finally, estimated bubble size has been compared and analysed with existing bubble size estimation correlations. Future work will focus on the effect of different reconstruction algorithms and permittivity models on bubble size estimation to get more comprehensive understanding of bubble behaviour to examine the capability of ECT at estimating single bubble size within fluidized bed.",
keywords = "Bubble size estimation, COMSOL simulation, Cut-off value, ECT sensor",
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Li, X, Jaworski, AJ & Mao, X 2016, Investigation of bubble behaviour in a gas-solid fluidized bed by means of a twin-plane ECT sensor. in Proceedings of the 8th World Congress on Industrial Process Tomography, (Iguassu Falls, Brazil: 26-29 September 2016)., B4, World Congress on Industrial Process Tomography, International Society for Industrial Process Tomography, 8th World Congress on Industrial Process Tomography, Iguassu Falls, Brazil, 26/09/16.

Investigation of bubble behaviour in a gas-solid fluidized bed by means of a twin-plane ECT sensor. / Li, Xiaoxu; Jaworski, AJ; Mao, Xiaoan.

Proceedings of the 8th World Congress on Industrial Process Tomography, (Iguassu Falls, Brazil: 26-29 September 2016). International Society for Industrial Process Tomography, 2016. B4 (World Congress on Industrial Process Tomography).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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T1 - Investigation of bubble behaviour in a gas-solid fluidized bed by means of a twin-plane ECT sensor

AU - Li, Xiaoxu

AU - Jaworski, AJ

AU - Mao, Xiaoan

PY - 2016

Y1 - 2016

N2 - Fluidized beds are used extensively in chemical engineering applications, such as food processing, combustion, gasification processes and pharmaceutical industry. However, due to their complex fluid mechanical characteristics (for example bubble size and bubble velocity), conventional measuring techniques do not permit a sufficient understanding. Electrical Capacitance Tomography (ECT) has been developed over the last few decades as a non-invasive measurement technique and applied to study gas-solids fluidized beds. Although many researchers investigated relationships governing bubble sizes, the influence of cut-off value (a grey level value distinguishing gas and solid phases) of bubble boundary on the bubble size estimation is still not fully understood. A twin-plane ECT sensor with 10 mm-long measuring electrodes has been designed and fabricated to study the single bubbling regime in a gas-solids model fluidized bed. To investigate the influence of the cut-off value on bubble size estimation, different diameter hollow plastic balls have been imaged while the bed is at packed bed state. Appropriate MATLAB code has been developed to extract the cut-off values of the boundary for these plastic balls. Based on the cut-off values, bubble size within single bubbling regime has been estimated by LBP and iterative LBP image reconstruction algorithms. Finally, estimated bubble size has been compared and analysed with existing bubble size estimation correlations. Future work will focus on the effect of different reconstruction algorithms and permittivity models on bubble size estimation to get more comprehensive understanding of bubble behaviour to examine the capability of ECT at estimating single bubble size within fluidized bed.

AB - Fluidized beds are used extensively in chemical engineering applications, such as food processing, combustion, gasification processes and pharmaceutical industry. However, due to their complex fluid mechanical characteristics (for example bubble size and bubble velocity), conventional measuring techniques do not permit a sufficient understanding. Electrical Capacitance Tomography (ECT) has been developed over the last few decades as a non-invasive measurement technique and applied to study gas-solids fluidized beds. Although many researchers investigated relationships governing bubble sizes, the influence of cut-off value (a grey level value distinguishing gas and solid phases) of bubble boundary on the bubble size estimation is still not fully understood. A twin-plane ECT sensor with 10 mm-long measuring electrodes has been designed and fabricated to study the single bubbling regime in a gas-solids model fluidized bed. To investigate the influence of the cut-off value on bubble size estimation, different diameter hollow plastic balls have been imaged while the bed is at packed bed state. Appropriate MATLAB code has been developed to extract the cut-off values of the boundary for these plastic balls. Based on the cut-off values, bubble size within single bubbling regime has been estimated by LBP and iterative LBP image reconstruction algorithms. Finally, estimated bubble size has been compared and analysed with existing bubble size estimation correlations. Future work will focus on the effect of different reconstruction algorithms and permittivity models on bubble size estimation to get more comprehensive understanding of bubble behaviour to examine the capability of ECT at estimating single bubble size within fluidized bed.

KW - Bubble size estimation

KW - COMSOL simulation

KW - Cut-off value

KW - ECT sensor

UR - http://www.isipt.org/publications.html

M3 - Conference contribution

T3 - World Congress on Industrial Process Tomography

BT - Proceedings of the 8th World Congress on Industrial Process Tomography, (Iguassu Falls, Brazil: 26-29 September 2016)

PB - International Society for Industrial Process Tomography

ER -

Li X, Jaworski AJ, Mao X. Investigation of bubble behaviour in a gas-solid fluidized bed by means of a twin-plane ECT sensor. In Proceedings of the 8th World Congress on Industrial Process Tomography, (Iguassu Falls, Brazil: 26-29 September 2016). International Society for Industrial Process Tomography. 2016. B4. (World Congress on Industrial Process Tomography).