Abstract
The effect of the bed diameter on the gas-solids flow characteristics inside a cylindrical fluidized bed is investigated numerically using a two-fluid model based on the kinetic theory of granular flow. Particle bed diameters of 0.10, 0.15, 0.30 and 0.60 m are studied, containing particles of 1.1 mm diameter and a density of 800 kg/m3 (Geldart B), using an inlet gas velocity of 2.5Umf. The equivalent bubble diameter shows an increasing trend with height in the bed and bed diameter. Slugging behavior is observed in a smaller bed and/or above a bed height of approximately twice the bed diameter. The porosity near the axis is higher for a smaller bed and gradually decreases for a larger bed. Different particle circulation patterns are observed for different bed sizes. The center of circulation vortex at the bottom for a smaller bed lies approximately at r/R = 0.5 and this center is shifted to r/R = 0.8 for a larger bed. The upper particle circulation obtains a more elongated shape for a smaller and deeper bed in comparison to a larger bed diameter. The particle flow characteristics are nearly the same for the 0.30 and 0.60 m diameter beds, irrespective of the difference in bubble size. This shows that the bed size effect levels off beyond a 0.30 m diameter column for Geldart B particles.
Original language | English |
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Pages | 487-492 |
Publication status | Published - 2014 |
Externally published | Yes |
Event | 11th International Conference on Fluidized Bed Technology, CFB 2014 - Beijing, China Duration: 14 May 2014 → 17 May 2014 |
Conference
Conference | 11th International Conference on Fluidized Bed Technology, CFB 2014 |
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Country/Territory | China |
City | Beijing |
Period | 14/05/14 → 17/05/14 |