Local time-averaged gas holdup in fluidized bed reactor using gamma ray computed tomography technique (CT)

Abdelsalam Efhaima,Muthanna H Al-Dahhan

doi:10.1007/s40090-015-0048-6

Abdelsalam Efhaima, Muthanna H Al-Dahhan

Open Access

https://doi.org/10.1007/s40090-015-0048-6

Copy DOI

Abstract

Many invasive and non-invasive techniques have been used to analyze the hydrodynamics of fluidized beds. In this study, the effect of superficial gas velocity and bed particle density on the hydrodynamics of gas–solid fluidized beds was investigated by using a cylindrical plexiglas fluidized bed column, 14 cm in diameter. Air at room temperature was used as the fluidizing gas and two different Geldart type-B particles were used: glass beads and copper particles with material densities of 2.5 and 5.3 g/cm3, respectively, with the same size particle, 210 µm. To measure the time-averaged cross-sectional gas and solid holdup distribution, gamma ray computed tomography was used for the first time as a non-invasive technique instead of using X-rays (due to the height attenuation of the copper particles). The results show that gas holdup increases by increasing the superficial gas velocity, and decreasing the particle density increases the gas holdup in the bed.

Highlights

Contacting solid particles with gases is often a necessity in many industrial operations
The results show that gas holdup increases by increasing the superficial gas velocity, and decreasing the particle density increases the gas holdup in the bed
The time-averaged cross-sectional gas holdup distributions (Fig. 5) and the radial gas holdup profiles (Fig. 6) exhibit good reproducibility, Fig. 5a, b exhibits similar cross-sectional gas holdup distributions to those obtained for runs no. 1 and no. 2, the results correspond to the superficial gas velocity of 25 cm/s and the axial location of H/D = 1.7

Summary

Introduction

Contacting solid particles with gases is often a necessity in many industrial operations. The effect of superficial gas velocity and bed particle density on the hydrodynamics of gas–solid fluidized beds was investigated by using a cylindrical plexiglas fluidized bed column, 14 cm in diameter. To measure the time-averaged cross-sectional gas and solid holdup distribution, gamma ray computed tomography was used for the first time as a non-invasive technique instead of using X-rays (due to the height attenuation of the copper particles).

Results

Conclusion