The effects of solids density and void fraction on the bubble rise velocity in a liquid-solid fluidized bed

✍ Scribed by Michael J. Bly; R.Mark Worden

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 615 KB
• Volume: 47
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(92)85036-b

✦ Synopsis

The effects of solids density and void fraction on the bubble rise velocity of distorted spherical and circular-cap bubbles in two-and three-dimensional liquid-solid fluidixed beds have been examined. Specific gravities of the solid phase ranged from 1.02 to 2.50, and the equivalent bubble diameter varied from 0.07 to 2.0 cm. Bubble rise velocities were found to decrease with increasing solids fraction and density and to increase with bubble size. The reduction in the bubble rise velocity due to the presence of the solid phase was semi-empirically modeled for bubble diameters greater than 0.20 cm using a virial expansion in the solids fraction. Smaller bubbles seemed to be influenced by local liquid flow patterns. The bubble rise velocity model was found to fit experimental results and literature values for solids fractions up to 0.43.