Electrostatic charging in gas–solid fluidized beds : effects of gas composition, humidity, and interparticle charging
department or school: Applied Science, Faculty of
department or school: Chemical and Biological Engineering, Department of
data provider: DSpace
degree campus: UBCV
creator: Hou, Jiang Tian
issued: 2025-11-27T23:40:41Z
issued: 2025
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Electrostatic charging is a pervasive challenge in gas–solid fluidized beds, arising from continuous contacts among fluidizing particles and between particles and the column wall. In commercial operations such as polyolefin polymerization, pharmaceutical manufacturing, and dust handling, uncontrolled electrostatics can lead to wall sheeting, particle agglomeration, and even safety hazards. Despite decades of research, the interplay between particle properties, gas-phase conditions, and boundary effects remains insufficiently understood, limiting the effectiveness of mitigation strategies. This thesis systematically investigates the mechanisms and controlling factors of electrostatic charging in gas–solid fluidized beds. Fluidization experiments were conducted with high-density polyethylene (HDPE) and glass particles under different fluidizing gases and varying relative humidity levels. The results demonstrate that gas composition regulates the saturation charge via its dielectric breakdown strength, with argon in particular shown to effectively suppress charge accumulation of HDPE particles and the associated wall fouling and agglomeration. Humidity, in turn, critically influences both charge generation and dissipation. Its effectiveness is strongly material-dependent and is especially pronounced for glass beads, which are more hydrophilic and possess relatively lower electrical resistivity. Additional studies highlight the role of wall material and grounding in determining charge polarity and accumulation within the bed. To isolate interparticle charging, a custom-designed acoustic levitation platform was developed to enable controlled collisions between particles of the same or different sizes and materials. These experiments confirmed that for HDPE particles, collisions between dissimilar-sized particles consistently led to size-dependent bipolar charging, while collisions between similar-sized particles produced random polarity outcomes. In contrast, material pa…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/93045
note: ELECTROSTATIC CHARGING IN GAS–SOLID FLUIDIZED BEDS: EFFECTS OF GAS COMPOSITION, HUMIDITY, AND INTERPARTICLE CHARGING by Jiang Tian Hou B.Eng., Imperial College London, London, UK, 2008 M. Eng., University of British Columbia, Vancouver, Canada, 2012 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Chemical and Biological Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) November 2025 © Jiang Tian Hou, 2025 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: Electrostatic Charging in Gas–Solid Fluidized Beds: Effects of Gas Composition, Humidity, and Interparticle Charging submitted by Jiang Tian Hou in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Chemical and Biological Engineering Examining Committee: Tony (Xiaotao) Bi, Professor, Chemical and Biological Engineering, UBC Supervisor John R. Grace, Professor, Chemical and Biological Engineering, UBC Co-supervisor James J. Feng, Professor, Chemical and Biological Engineering, UBC Supervisory Committee Member Fariborz Taghipour, Professor, Chemical and Biological Engineering, UBC Supervisory Committee Member Mark Martinez, Professor, Chemical and Biological Engineering, UBC University Examiner Rizhi Wang, Professor, Materials Engineering, UBC University Examiner Jun Yao, Professor, College of Mechanical and Transportation Engineering, China University of Petroleum-Beijing External Examiner iii Abstract Electrostatic charging is a pervasive challenge in gas–solid fluidized beds, arising from continuous contacts among fluidizing particles and between particles and the column wall. In commercial operations such as polyolefin polymerization, pharmaceutical manufacturing, and dust handling, uncontrolled electrostatics can lead to wall sheeting, particle agglomera…
has type: Thesis/Dissertation
date issued: 2026-05
is shown at: 10.14288/1.0450885
language: eng
degree discipline: Chemical and Biological Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Bi, Xiaotao
contributor: Grace, John R.
type: Text
identifier URI: http://hdl.handle.net/2429/93045