Understanding the jetting phenomena near the gas distributor plate in a fluidized bed is important to gas-solids mixing, heat and mass transfer, and erosion on any bed internals, which can all affect the performance of the bed. Moreover, acoustic vibration in a fluidized bed can be used to enhance the fluidization quality of particulate matter. Characterizing the jetting structure using X-ray computed tomography in a 3D fluidized bed, with and without acoustic intervention, is completed in this study. A 10.2 cm ID fluidized bed filled with glass beads, with material density of 2500 kg/m3 and particles sizes ranging between 212–600 μm, is used in these experiments. X-ray computed tomography (CT) imaging is used to determine local time-average gas holdup. From this information, qualitative characteristics of the hydrodynamic structure of the multiphase flow system are determined. Local time-average gas holdup images of the fluidized bed under acoustic intervention at a high superficial gas velocity show that jets produced near the aeration plate merge with other jets at a higher axial position of the bed compared to the no acoustic condition. Acoustic fluidized beds also have a fewer number of active jets than the no acoustic fluidized bed, which allowed for a more homogeneous gas holdup region deep into the bed. Hence, the acoustic presence has a significant effect on the jetting phenomena near the distributor plate of the fluidized bed.
Available at: http://works.bepress.com/theodore_heindel/56/
This proceedings is published as Escudero, D., and Heindel, T.J., “Characterizing Jetting in an Acoustic Fluidized Bed using XRay Computed Tomography,” Proceedings of the ASME 2014 Fluids Engineering Division Summer Meeting, August 3-7, 2014, Chicago, Illinois Paper FEDSM2014-21161, 2014. DOI: 10.1115/FEDSM2014-21161. Posted with permission.