EFFECT OF FLUIDIZED BED DIAMETER ON FLUIDIZATION DYNAMICS
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.
Vikrant Verma Johan T.Padding Niels G.Deen J.A.M.Kuipers
Eindhoven University of Technology,Dept.of Chemical Engineering and Chemistry PO Box 513,5600 MB Eindhoven,The Netherlands
国际会议
The 11th International Conference on Fluidized Bed Technology(CFB-11)(第十一届流化床技术国际会议)
北京
英文
487-492
2014-05-14（万方平台首次上网日期，不代表论文的发表时间）