Bubble Splitting in a Pseudo-2D Gas-Solid Fluidized Bed for Geldart B-Type Particles

• Published in: Chemical engineering & technology 2014-12, Vol.37 (12), p.2096-2102
• Main Authors: Movahedirad, Salman, Dehkordi, Asghar Molaei, Molaei, Esmaeel Abbaszade, Haghi, Mehdi, Banaei, Mohammad, Kuipers, Johannes A. M.
• Format: Article
• Language: English
• Subjects: Breakage; Bubble splitting; Bubbles; Bubbling fluidized beds; Chemical engineering; Constants; Digital; Digital image analysis; Fluidized beds; Image analysis; Splitting
• ISSN: 0930-7516; 1521-4125
• DOI: 10.1002/ceat.201300565

Bubble splitting in 2D gas‐solid freely bubbling fluidized beds is experimentally investigated using digital image analysis. The quantitative results can be applied for the development of a new breakage model for bubbly fluidized beds, especially discrete bubble models. The variation of splitting frequency with bubble diameter, new resulting bubble volumes, positions, and also the assumptions of mass and momentum conservation for bubbles after breakage are studied in detail. Small bubbles are found to be more stable than large ones and nearly all mother bubbles split into two almost equally sized daughter bubbles. The momentum of gas bubbles in the vertical direction remains approximately constant after breakage, whereas that of bubbles in the horizontal direction changes with no clear trend. The effect of fluidizing gas velocity in breakage frequency is also examined. The behavior of gas bubbles plays a key role in heat‐ and mass‐transfer operations in fluidized beds. Bubble splitting for Geldart B‐type particles under varying conditions was investigated in a pseudo‐2D gas‐solid fluidized bed by digital image analysis. The quantitative results can facilitate the development of new breakage models for bubbly fluidized beds and are particularly relevant for discrete bubble modeling.