Characterisation of solid hydrodynamics in a three-phase stirred tank reactor with positron emission particle tracking (PEPT)

It is challenging to measure the hydrodynamics of stirred tank reactors when they contain multiphase flows comprising liquid, gas bubbles and particles. Radioactive particle tracking techniques such as positron emission (PEPT) are only established determine internal flow behaviour due inherent opacity density fluid vessel walls. The profiles solids an important tool for robust reactor design optimisation offer insight into underlying transport processes particle–fluid–bubble interactions applications froth flotation. In this work, measurements with PEPT were performed two tracer particles differing in surface hydrophobicity characterise a baffled agitated Rushton turbine. location data from averaged time estimate probability function (PDF) velocity individual voxels. peaks these voxel distributions used produce different azimuthal horizontal slices. Bimodal vertical observed impeller radial jet which suggest experienced trajectory crossing effects inertia. Statistical tests compare hydrophilic hydrophobic particles, indicated similar average liquid or pulp phase differences near air inlet, discharge stream pulp–froth interface. With tracers designed represent gangue valuable mineral species, reveal bubble–particle attachment entrainment. • Positron flow. Solid three-phase gas, solids. Comparison behaviour. Observations interaction bubble field.