Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310341
Title: Particle motion in fluidised beds.
Author: Stein, Matthias Gert.
Awarding Body: University of Birmingham
Current Institution: University of Birmingham
Date of Award: 1999
Availability of Full Text:
Access through EThOS:
Abstract:
Gas fluidised beds are important components in many process industries, e.g. coal combustors and granulators, but not much is known about the movement of the solids. Positron Emission Particle Tracking (PEPT) enables the movement of a single, radioactive tracer particle to be followed rapidly and faithfully. Experiments were carried out in columns sized between 70 and 240mm diameter, operating in the bubbling regime at ambient process conditions using particles of group B and D (Geldart Classification). Particle motion was tracked and the data applied to models for particle movement at the gas distributor as well as close to other surfaces and to models for particle circulation in beds of cohesive particles. In the light of these data, models for particle and bubble interaction, particle circulation, segregation, attrition, erosion, heat transfer and fluidised bed scale-up rules were reassessed. Particle motion is directly caused by bubble motion, and their velocities were found to be equal for particles travelling in a bubble. PEPT enables particle circulation to be measured, giving a more accurate correlation for future predictions. Particle motion follows the scale-up rules based on similarities of the bubble motion in the bed. A new group of parameters was identified controlling the amount ofattrition in fluidised beds and a new model to predict attrition is proposed.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.310341  DOI: Not available
Keywords: PARTICLES; MOTION; TRACER TECHNIQUES; FLUIDIZED BEDS; BUBBLES; POSITRON DETECTION Particles (Nuclear physics) Nuclear reactions Chemical engineering
Share: