Investigation of fluidized bed behaviour using electrical capacitance tomography

Azzi, Abdelwahid; Bouyahiaoui, Hiba; Sofiane Berrouk, Abdallah; Hunt, Andrew; Lowndes, Ian S

Abstract

The temporal and cross?sectional distributions of particles in a 127?mm diameter fluidized bed have been obtained using a new generation, high?speed electrical capacitance tomography. Two planes of eight electrodes were used and mounted at 160?mm and 660?mm from the gas distributor which was a 3?mm thick porous plastic plate (maximum pore size of 50 ?m?70 ?m). 3?mm diameter, nearly?spherical polyethylene granules made up the bed. Experiments at sampling frequencies of 200?2000 cross?sections per second and gas superficial velocities from just below the minimum fluidization to 83% above minimum fluidization velocities were used. The time series of the cross?sectional average void fractions have been examined both directly and in amplitude and frequency space. The last two used probability density functions and power spectral densities. The information gathered shows that the fluidized bed was operating in the slugging mode, which is not surprising given the size of the particles. It has been found that an increase in the excess gas velocity above the minimum fluidization velocity resulted in an increase in the mean void fraction, an increase in the length and velocity of the slug bubbles as well as the bed height, and a slight decrease in the slug frequency. The results are presented in a level of detail suitable for comparison with later numerical simulation.

Citation

Azzi, A., Bouyahiaoui, H., Sofiane Berrouk, A., Hunt, A., & Lowndes, I. S. (2020). Investigation of fluidized bed behaviour using electrical capacitance tomography. Canadian Journal of Chemical Engineering, 98(8), 1835-1848. https://doi.org/10.1002/cjce.23748

• Journal Article Type: Article
• Acceptance Date: Nov 12, 2019
• Online Publication Date: Mar 14, 2020
• Publication Date: 2020-08
• Deposit Date: Nov 14, 2019
• Publicly Available Date: Mar 15, 2021
• Journal: Canadian Journal of Chemical Engineering
• Print ISSN: 0008-4034
• Electronic ISSN: 1939-019X
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 98
• Issue: 8
• Pages: 1835-1848
• DOI: https://doi.org/10.1002/cjce.23748
• Public URL: https://nottingham-repository.worktribe.com/output/3277685
• Publisher URL: https://onlinelibrary.wiley.com/doi/abs/10.1002/cjce.23748
• Additional Information: This is the peer reviewed version of the following article: Azzi, A., Bouyahiaoui, H., Berrouk, A.S., Hunt, A. and Lowndes, I.S. (2020), Investigation of Fluidized Bed Behavior Using Electrical Capacitance Tomography. Can J Chem Eng. Accepted Author Manuscript, which has been published in final form at https://doi.org/10.1002/cjce.23748. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.