Understanding the dynamics of pulp fibre suspension dewatering
department or school: Applied Science, Faculty of
department or school: Chemical and Biological Engineering, Department of
data provider: DSpace
degree campus: UBCV
creator: Paterson, Daniel Thomas
issued: 2020-07-20T16:59:01Z
issued: 2020
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Dewatering of pulp fibre suspensions is a fundamental process in many unit operations in the production of pulp and paper. A theoretical understanding of the dynamics of these networking fibre suspensions can prove valuable in the design of industrial equipment and supplement the general field of compressive rheology. This project aims to provide a general understanding of the consolidation, in particular, how the network of fibres responds to the stresses experienced during dewatering events. This begins with assessing the robustness of our previous modelling effort, which extended the traditional multi-phase, deformable porous media frameworks, through the accommodation of a rate-dependent constitutive model for the solid effective stress (bulk viscosity). Robustness studies include: testing a large variety of pulp types, investigating low concentration dynamics, and using industrial and lab equipment. Results from these studies motivated extending studies of the solid network’s response during high speed dewatering and shear stress application. For each study, a combined theoretical and experimental approach was undertaken to formulate appropriate model equations, independently calibrate the required material parameters, and collect experimental dynamic dewatering results. Model robustness for varying pulp suspensions at intermediate concentrations utilized a Darcian flow cell to calibrate permeability, a uni-axial dewatering experiment to determine their compressive yield stress, and dynamic dewatering experiments at modest rates to characterize the suspension’s bulk viscosity. The low concentration investigation introduced experiments for calibrating permeability and compressive yield stress around the suspension’s gel point and utilized gravitational drainage experiments to gauge bulk viscosity’s importance. In both investigations, the inclusion of a sizable bulk viscosity was necessary to effectively represent the dewatering behaviour. Dewatering dynamics in …
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/75220
note: Understanding the Dynamics of Pulp Fibre SuspensionDewateringbyDaniel Thomas PatersonM.A.Sc., The University of British Columbia, 2016B.A.Sc., The University of British Columbia, 2013A THESIS SUBMITTED IN PARTIAL FULFILLMENTOF THE REQUIREMENTS FOR THE DEGREE OFDoctor of PhilosophyinTHE FACULTY OF GRADUATE AND POSTDOCTORALSTUDIES(Chemical and Biological Engineering)The University of British Columbia(Vancouver)July 2020© Daniel Thomas Paterson, 2020The following individuals certify that they have read, and recommend to the Fac-ulty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled:Understanding the Dynamics of Pulp Fibre Suspension Dewateringsubmitted by Daniel Thomas Paterson in partial fulfillment of the requirementsfor the degree of Doctor of Philosophy in Chemical and Biological Engineering.Examining Committee:Mark Martinez, Chemical and Biological EngineeringCo-SupervisorNeil Balmforth, MathematicsCo-SupervisorDaan Maijer, Materials EngineeringUniversity ExaminerBrian Wetton, MathematicsUniversity ExaminerAnders Dahlkild, Engineering Mechanics, KTHExternal ExaminerAdditional Supervisory Committee Members:John Frostad, Chemical and Biological EngineeringSupervisory Committee MemberRobert Gooding, VP of Aikawa Fiber Technologies, Mechanical EngineeringSupervisory Committee MemberiiAbstractDewatering of pulp fibre suspensions is a fundamental process in many unit op-erations in the production of pulp and paper. A theoretical understanding of thedynamics of these networking fibre suspensions can prove valuable in the designof industrial equipment and supplement the general field of compressive rheol-ogy. This project aims to provide a general understanding of the consolidation, inparticular, how the network of fibres responds to the stresses experienced duringdewatering events. This begins with assessing the robustness of our previous mod-elling effort, which extended the traditional multi-phase, deformable porous mediaframeworks, through the a…
has type: Thesis/Dissertation
date issued: 2020-11
is shown at: 10.14288/1.0392476
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
type: Text
identifier URI: http://hdl.handle.net/2429/75220