Characterisation and prediction of particle attrition in lean phase pneumatic conveyors: the influence of particle concentration

This thesis aimed to determine the influence of particle concentration on the magnitude of measured particle attrition within horizontal, homogeneous lean phase pneumatic conveying systems. Furthermore, to propose a characterisation method for predicting the magnitude of particle attrition in such pneumatic conveying systems. After conducting an extensive literature review, no conclusive research which quantitatively described the relationship between particle concentration and the magnitude of particle attrition inflicted within lean phase pneumatic conveying was found. Additionally, there was no generally accepted model to predict the magnitude of particle attrition caused by such systems. Two test facilities were designed, constructed, commissioned and employed for the experimental programme: - A ‘centrifugal accelerator style’ particle impact tester; for characterisation of particle attrition behaviour under closely controlled impact velocities and angles. - A pilot scale vacuum pressure pneumatic conveying system containing a single bend; to study the influence of geometric and conveying variables, on particle attrition. From experiments with the above test facilities, no indication that particle concentration affected the magnitude of particle attrition could be discerned. However, experimentation using industrially-sized pneumatic conveyors, found increasing particle concentration reduced attrition. For the industrial systems it was proposed that reduced attrition was due to their geometrical features which influenced the relationship between the particle velocity distribution and particle concentration. The centrifugal impact tester was used to carry out factorial experiments to determine the individual influences of particle impact velocity, angle, and particle size. An interpolation method was proposed, to reduce the number of experiments required to characterise particle attrition behaviour. Through evaluating different techniques for calculating the mean particle impact angle at the bend in the pilot scale vacuum conveyor, the particle attrition behaviour was reconciled to that measured in the centrifugal impact tester. This enabled the prediction of particle attrition within such lean phase pneumatic conveying systems, based on a bench scale characterisation technique.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

University of Greenwich

Year dc:date.issued

2018

Author dc:creator

• Kotzur, Benjamin Andrew

Advisors dc:contributor.advisor

• Bradley, Michael
• Berry, Robert

• TJ Mechanical engineering and machinery

Language dc:language

en