Bubbling and Slugging of Geldart Group A Powders in Small Diameter Columns

Weibin Kong (1) , Tianwei Tan (2) , Jan Baeyens , Gilles Flamant (3) , Huili Zhang (2)

1 Beijing University of Chemical Technology
2 KU Leuven - Catholic University of Leuven = Katholieke Universiteit Leuven
3 PROMES - Procédés, Matériaux et Energie Solaire

Bubbling and slugging were investigated in a 0.05 m I.D. bed of Geldart group A powders. The slugging characteristics were assessed in terms of the operating parameters. Neither bed height nor particle properties affect the excess gas velocities at the onset of slugging, predictable by the Stewart criterion. Slugging characteristics (length, frequency) and fluidized bed properties were determined. The bottom zone of the bed is freely bubbling and the bubble sizes can be predicted by dB = 0.047H0.37. Mostly wall slugs occur higher up the bed when dB exceeds about 50% of the column diameter. The slug frequency varies with the height in the bed, but reaches an equilibrium value of 1 Hz for bed heights exceeding ~ 1m. Three distinct zones appear in a deep bed of group A powders,. The design and scale-up should combine the bubbling and slugging modes within their corresponding regions in the bed.

Domaines: Sciences de l'ingénieur [physics]; Génie des procédés

Weibin Kong, Tianwei Tan, Jan Baeyens, Gilles Flamant, Huili Zhang. Bubbling and Slugging of Geldart Group A Powders in Small Diameter Columns. Industrial and engineering chemistry research, 2017, 56 (14), pp.4136 - 4144. ⟨10.1021/acs.iecr.6b04798⟩. ⟨hal-01892647⟩