Determination of particle exchange rates at over-flow weirs in horizontal fluidised beds by particle tracking velocimetry

摘要

Residence time distributions (RTDs) in horizontal fluidised beds have a huge effect on solid product properties and are influenced by the internal design of the apparatus,e.g.the separation into different compartments by weirs.Weirs can be passed in or against the overall solid transport direction,with the back-flow resulting in axial dispersion,which is a measure of the spread of the RTD.Therefore,the ratio of exchange rates at weirs under different fluidisation conditions provides information on axial dispersion.In this work,a methodology based on particle tracking velocimetry is presented to obtain information on the exchange rates of particles at weirs in horizontal fluidised beds.The internal recirculation is studied for over-flow weirs with respect to different fluidisation conditions,providing a first step towards determining the effects of weirs and fluidisation conditions on axial dispersion and RTDs in horizontal fluidised beds.