Saayman, JeanNicol, WillieRuud van Ommen, J.Mudde, Robert F.2013-10-312013-10-312013Saayman, J, Nicol, W, Ruud van Ommen, J ... et al 2013, 'Fast X-ray tomography for the quantification of the bubbling-, turbulent- and fast fluidization- flow regimes and void structures', Chemical Engineering Journal, vol. 234, pp. 437-447.1385-8947 (print)1873-3212 (online)10.1016/j.cej.2013.09.008http://hdl.handle.net/2263/32226Multiple fluidization regimes were studied using X-ray tomography. Geldart B sand particles were used in a 14 cm (ID) column with a dual cyclone return system. Cross sectional solids concentration (/) was measured and the time averaged / ð /Þ decreased with velocity and axial height except in the turbulent regime where / remained constant. Radial profiles of / decreased to the centre, while all turbulent regime velocities resulted in similar radial / profiles. Results confirm the bubbling-turbulent transition velocity (Uc) determined from pressure fluctuations is a reliable quantification technique. The system exhibited slugging behaviour at higher bubbling regime velocities with voids taking on cylindrical shapes. Turbulent regime voids were characterised by elongated cylinders with diameters slightly less than the bubbling regime’s slugs or fast fluidization regime’s core annulus. Distribution curves of the / signal indicated a distinct dense phase in the bubbling and turbulent regime with a velocity independent solid concentration. Void velocity analysis suggested that the bubble linking algorithm was unable to detect fast rising voids at higher velocities.en© 2013 Elsevier Ltd. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Chemical Engineering Journal.Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Chemical Engineering Journal, vol. 234, pp. 437-447, 2013, doi : 10.1016/j.cej.2013.09.008Fast X-ray tomographyVoid behaviourCross-sectional solids concentrationFluidization flow regime characterizationFluidizationTomographyPostprint Article