Abstract
Experimental work on the entrainment of an FCC powder was carried out in 76 mm and 152 mm glass columns. Fluidization tests were carried out batchwise and continuously at velocities between 0.2 m/s and 0.8 m/s. Non-cohesive fine powders and cohesive superfine powders were added to a coarse base FCC powder in proportions which ensured that the mixture remained within Geldart's Group A. The entrainment rate constant, K(i∞)(*), is found to depend slightly on the fines concentration in the bed. Our work has confirmed that there is a critical particle size at which K(i∞)(*) no longer increases as particle size decreases, and may even decrease. Several mechanisms are postulated to explain this but from the experimental results it is concluded that interparticle adhesion forces between the very fine particles play an important role. An empirical correlation to predict K(i∞)(*), below the point where levelling off occur is proposed.
Original language | English |
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Pages (from-to) | 175-195 |
Number of pages | 21 |
Journal | Chemical Engineering Communications |
Volume | 173 |
Publication status | Published - Jun 1999 |
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Keywords
- Elutriation rate constant
- Entrainment
- Entrainment flux
- Fines
- Fluidized bed
- Superfines
ASJC Scopus subject areas
- Chemical Engineering(all)
Cite this
The elutriation of fine and cohesive particles from gas fluidized beds. / Tasirin, Siti Masrinda; Geldart, D.
In: Chemical Engineering Communications, Vol. 173, 06.1999, p. 175-195.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The elutriation of fine and cohesive particles from gas fluidized beds
AU - Tasirin, Siti Masrinda
AU - Geldart, D.
PY - 1999/6
Y1 - 1999/6
N2 - Experimental work on the entrainment of an FCC powder was carried out in 76 mm and 152 mm glass columns. Fluidization tests were carried out batchwise and continuously at velocities between 0.2 m/s and 0.8 m/s. Non-cohesive fine powders and cohesive superfine powders were added to a coarse base FCC powder in proportions which ensured that the mixture remained within Geldart's Group A. The entrainment rate constant, K(i∞)(*), is found to depend slightly on the fines concentration in the bed. Our work has confirmed that there is a critical particle size at which K(i∞)(*) no longer increases as particle size decreases, and may even decrease. Several mechanisms are postulated to explain this but from the experimental results it is concluded that interparticle adhesion forces between the very fine particles play an important role. An empirical correlation to predict K(i∞)(*), below the point where levelling off occur is proposed.
AB - Experimental work on the entrainment of an FCC powder was carried out in 76 mm and 152 mm glass columns. Fluidization tests were carried out batchwise and continuously at velocities between 0.2 m/s and 0.8 m/s. Non-cohesive fine powders and cohesive superfine powders were added to a coarse base FCC powder in proportions which ensured that the mixture remained within Geldart's Group A. The entrainment rate constant, K(i∞)(*), is found to depend slightly on the fines concentration in the bed. Our work has confirmed that there is a critical particle size at which K(i∞)(*) no longer increases as particle size decreases, and may even decrease. Several mechanisms are postulated to explain this but from the experimental results it is concluded that interparticle adhesion forces between the very fine particles play an important role. An empirical correlation to predict K(i∞)(*), below the point where levelling off occur is proposed.
KW - Elutriation rate constant
KW - Entrainment
KW - Entrainment flux
KW - Fines
KW - Fluidized bed
KW - Superfines
UR - http://www.scopus.com/inward/record.url?scp=0033150017&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033150017&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0033150017
VL - 173
SP - 175
EP - 195
JO - Chemical Engineering Communications
JF - Chemical Engineering Communications
SN - 0098-6445
ER -