Bubble size and radial gas hold‐up distributions in a slurry bubble column using ultrafast electron beam X‐ray tomography |
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| Authors: | Swapna Rabha Markus Schubert Michael Wagner Dirk Lucas Uwe Hampel |
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| Affiliation: | 1. Experimental Thermal Fluid Dynamics, Institute of Fluid Dynamics, Helmholtz‐Zentrum Dresden‐Rossendorf, , Dresden, 01314 Germany;2. AREVA Endowed Chair of Imaging Techniques in Energy and Process Engineering, Dresden University of Technology, , 01062 Dresden, Germany |
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| Abstract: | Gas hold‐up and bubble size distribution in a slurry bubble column (SBC) were measured using the advanced noninvasive ultrafast electron beam X‐ray tomography technique. Experiments have been performed in a cylindrical column (DT = 0.07 m) with air and water as the gas and liquid phase and spherical glass particles (dP = 100 μm) as solids. The effects of solid concentration (0 ≤ Cs ≤ 0.36) and superficial gas velocity (0.02 ≤ UG ≤ 0.05 m/s) on the flow structure, radial gas hold‐up profile and approximate bubble size distribution at different column heights in a SBC were studied. Bubble coalescence regime was observed with addition of solid particles; however, at higher solid concentrations, larger bubble slugs were found to break‐up. The approximate bubble size distribution and radial gas hold‐up was found to be dependent on UG and Cs. The average bubble diameter calculated from the approximate bubble size distribution was increasing with increase of UG. The average gas hold‐up was calculated as a function of UG and agrees satisfactorily with previously published findings. The average gas hold‐up was also predicted as a function of Cs and agrees well for low Cs and disagrees for high Cs with findings of previous literature. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1709–1722, 2013 |
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| Keywords: | slurry bubble column gas hold‐up bubble size distribution ultrafast electron beam X‐ray tomography |
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