Investigation of Downflow Bubble Columns: Experiments and Modeling

Upadhyay, R. K.; Kaim, Jayant; Roy, Shantanu

doi:10.1252/jcej.08we165

Cited by 4 publications

(3 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The solid flow field for different inlet gas velocities and solid fluxes are mapped by using the RPT technique. RPT is a noninvasive velocimetry technique which tracks the motion of a single radioactive (γ-ray emitter) tracer particle with an array of strategically placed scintillation detectors around the zone of interest. − High-energy isotope 46 Sc doped in a glass bead of the same size (500 μm) is used as a tracer particle in the current experiment. This keeps the surface property of the tracer particle and other solids used in the experiments the same.…”

Section: Experimental Setup and Measurement Techniquementioning

confidence: 99%

“…This Lagrangian-position time series data is further used to calculate different flow quantities such as instantaneous velocities, mean velocities, root-mean-square (rms) velocities, granular temperature, and other turbulent quantities. The details of the postprocessing methodologies and algorithms are reported in previously published works with different multiphase reactors. − The RPT measurements are performed for different inlet gas velocities (7.6, 8.2, and 9.2 m/s) and solid fluxes (100, 150, and 200 kg/m 2 s), as listed in Table . The effects of these two parameters on the solid flow field are investigated in the current work.…”

Section: Experimental Setup and Measurement Techniquementioning

confidence: 99%

“…In the current work, the solid fraction is measured by the γ-ray densitometry technique , and the mean solid velocity is measured by measuring the time of flight (mean residence time) , of the solid phase between two known positions in the dipleg. Figure shows the schematic diagram of both the measurements performed in the dipleg.…”

Section: Solid Flux Measurementmentioning

confidence: 99%

See 2 more Smart Citations

Measurements of Solid Velocity in a Pilot-Scale Geldart’s Group B Circulating Fluidized Bed Using a Radioactive Particle Tracking Technique

Tribedi

Pillajetti

Kumari

et al. 2022

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Circulating fluidized bed (CFB) is used for a wide range of gas−solid reactions. However, most of the data reported on CFBs are for Geldart's group A particles, although the applications of Geldart's group B CFBs are numerous. In the current work, the solid flow field is deciphered in a pilot-plant-scale Geldart's group B CFB riser. Solid motion is tracked by using a radioactive particle tracking technique. The data are reported in a fully developed flow region of 0.1 m diameter and 6.5 m height CFB riser at different inlet gas velocities (7.6−9.2 m/s) and solid fluxes (100−200 kg/m 2 s). The different flow quantities such as mean axial and radial velocities, rootmean-square velocities, granular temperature, and turbulent intensities are calculated for all the cases. It is observed that solid motion predominantly lies in the axial direction. The probability distribution function of instantaneous solid velocity shows wider distribution near the wall as compared to the center of the riser. This shows that the probability of mesoscale metastable structure formation increases while moving from the center to the wall. Furthermore, the results show that the mean solid velocity largely depends on gas−solid interactions. However, for the fluctuating velocity, both gas−solid and solid−solid interactions are critical. The results indicate that the solid turbulent intensity in Geldart's group B riser is significantly higher than that in the group A riser. Hence, solid velocity fluctuations are higher in the group B riser.

show abstract