An investigation into slugging fluidized beds

Baeyens, Jan; Geldart, D.

doi:10.1016/0009-2509(74)85051-7

Cited by 183 publications

(109 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Based on the criterion given Ž . by Baeyens and Geldart 1974 , the minimum bed height for slugging is 0.9 m. In this work, to ensure no slug is present in the column, the static bed height is set at 0.35 m. The visual observation also reveals that there is no slug for these 60 m FCC particles during the experiments.…”

Section: Dynamic Beha©ior In the Bedmentioning

confidence: 96%

Bed nonhomogeneity in turbulent gas‐solid fluidization

Warsito

Fan

2003

AIChE Journal

View full text Add to dashboard Cite

show abstract

Section: Dynamic Beha©ior In the Bedmentioning

confidence: 96%

Bed nonhomogeneity in turbulent gas‐solid fluidization

Warsito

Fan

2003

AIChE Journal

View full text Add to dashboard Cite

show abstract

“…The initial increase in ΔP over the bottom section of the riser corresponds with forming a turbulent fluidized bed at the bottom of the riser (TFBB), however, with continued solids elutriation. At increased or reduced , it is followed by the collapse of the solids into a slugging state, with its characteristic Δ -fluctuation frequency of 0.7-1 Hz [13]. A further decrease of Table 1.…”

Section: Methodsmentioning

confidence: 99%

Choking Affects the Operation Diagram of a CFB Riser

Zhang

Degrève

Baeyens

et al. 2014

Journal of Powder Technology

Self Cite

View full text Add to dashboard Cite

Experiments in 3 different CFB risers have confirmed that common riser operations can be hampered in a well-defined (U, G) range where choking occurs. Geldart A-type powders were investigated. Experimental results of the choking velocity were empirically correlated, being about 30% lower than predicted by the correlation of Bi and Fan, but largely exceeding other predictions. Introducing the findings into the operation diagram presented by Mahmoudi et al. adds a region where stable riser operation is impossible. The adapted diagram enables CFB designers to better delineate the operating characteristics.

show abstract

“…Previous researchers (Noordergraaf, 1987, Baeyens andGeldart, 1974) had suggested that the size and shape of a particle have no effect on the slugging frequency or minimum slugging velocity. None of these or other earlier works consistently dealt with particles in the size range in which this study was undertaken.…”

Section: Effect Of Particle Shapementioning

confidence: 97%

Slugging characteristics of group d particles in fluidized beds

Dimattia¹,

Amyotte

Hamdullahpur

1997

Can J Chem Eng

View full text Add to dashboard Cite

Pressure fluctuations within a bed of Type D particles (coarse sand, long grain rice, red spring wheat, 10 mm glass beads, pearl barley and whole peas) were measured at various bed heights. Analysis of the pressure fluctuation profiles leads to correlations that predict the minimum slugging velocity and slugging frequency, within experimental ranges. Results reveal that past correlations have little success in predicting the slugging characteristics for large particles. Particle shape plays an important role on the type of slug formed and therefore on the values of slugging frequency and minimum slugging velocity. Large particles with low sphericity formed wall slugs with high slugging frequencies and required the greatest amount of excess air to achieve slugging.On a mesure a des hauteurs de lits differentes les fluctuations de pression dans un lit garni de particules de type D (sable grossier, riz a grains longs, ble de printemps rouge, billes de verre de 10 mm, orge perle et pois entiers). L'analyse des profils de fluctuation des pressions a conduit a des correlations qui predisent la vitesse de bouillonnage minimum et la frequence du bouillonnage, dans les gammes experimentales. Les resultats revelent que les correlations passees reussissent ma1 a predire les caracteristiques de bouillonnage pour les grosses particules. La forme des particules joue un rde important sur le type de bouchon forme et donc sur les valeurs de frequence du bouillonnage et la vitesse de bouillonnage minimum. Les grosses particules ayant une petite sphericite foment des bouchons aux parois avec des frequences de bouillonnage elevees, et elles necessitent le plus grand exces d'air pour realiser le bouillonnage.Keywords: fluidization, slugging frequency, slugging, pressure measurements, group D particles. revious works on the hydrodynamic phenomenon of P slugging in fluidized beds have spanned the last three decades. The majority of these works concern themselves with the study of small (Type A and/or B) spherical or sandlike particles. There has been no work exclusively on the particle scale presented in this study. It will be shown that the relatively straight forward procedure of analyzing pressure fluctuations in a fluidized bed is an effective method for determining when the bed enters the slugging regime.Fluidization, in a gas-solid bed, begins when the weight of the particles is balanced by the buoyancy and drag caused by the flow of gas through the bed (Ho, 1983). If the superficial gas velocity is raised above the minimum fluidization velocity, aggregative fluidization is achieved which is characterized by two distinct phases that can be observed within the bed. With a firther increase in gas velocity, a phenomenon may be observed in which the bubbles coalesce and appear to occupy the whole cross-section of the fluidized bed column. These bubbles are referred to as slugs and this phenomenon is called slugging. The superficial gas velocity at the onset of slugging is termed the minimum slugging velocity and the rate at which the...

show abstract

An investigation into slugging fluidized beds

Cited by 183 publications

References 9 publications

Bed nonhomogeneity in turbulent gas‐solid fluidization

Bed nonhomogeneity in turbulent gas‐solid fluidization

Choking Affects the Operation Diagram of a CFB Riser

Slugging characteristics of group d particles in fluidized beds

Contact Info

Product

Resources

About