Understanding the jetting phenomena near the gas distributor plate in a fluidized bed is important to gas–solid mixing, heat and mass transfer, and erosion to any bed internals, which can all affect the performance of the bed. Moreover, acoustic vibration in a fluidized bed can be used to enhance the fluidization quality of the particulate matter and influence the jetting behavior. Characterizing the jetting structure using X-ray computed tomography (CT) in a three-dimensional (3D) fluidized bed, with and without acoustic intervention, is the focus of this study. A 10.2 cm ID fluidized bed filled with glass beads and ground walnut shell, with material densities of 2500 kg/m3 and 1440 kg/m3, respectively, and particle sizes ranging between 212 and 600 μm, is used in these experiments. X-ray CT imaging is used to determine local time-average gas holdup. From this information, qualitative and quantitative characteristics of the hydrodynamic structure of the multiphase flow system are determined. Local time-average gas holdup images of the fluidized bed under acoustic intervention at a high superficial gas velocity show that jets produced near the aeration plate merge with other jets at a higher axial position of the bed compared to the no acoustic condition. Acoustic fluidized beds also have a fewer number of active jets than the no acoustic fluidized bed, which allowed for a more homogeneous gas holdup region deep in the bed. Hence, the acoustic presence has a significant effect on the jetting phenomena near the aeration plate in a fluidized bed.

References

References
1.
Yang
,
W.-C.
, and
Keairns
,
D. L.
,
1987
, “
A Study of Fine Particles Residence Time in a Jetting Fluidized Bed
,”
Powder Technol.
,
53
(
3
), pp.
169
178
.
2.
Ettehadieh
,
B.
,
Yang
,
W.-C.
, and
Haldipur
,
G. B.
,
1988
, “
Motion of Solids, Jetting and Bubbling Dynamics in a Large Jetting Fluidized Bed
,”
Powder Technol.
,
54
(
4
), pp.
243
254
.
3.
Guo
,
Q.
,
Tang
,
Z.
,
Yue
,
G.
,
Liu
,
Z.
, and
Zhang
,
J.
,
2001
, “
Flow Pattern Transition in a Large Jetting Fluidized Bed With Double Nozzles
,”
AIChE J.
,
47
(
6
), pp.
1309
1317
.
4.
Guo
,
Q.
,
Yue
,
G.
,
Liu
,
Z.
, and
Zhang
,
J.
,
2001
, “
Hydrodynamic Characteristics of a Two-Dimensional Jetting Fluidized Bed With Binary Mixtures
,”
Chem. Eng. Sci.
,
56
(
15
), pp.
4685
4694
.
5.
Chen
,
J.
,
Lu
,
X.
,
Liu
,
H.
, and
Liu
,
J.
,
2008
, “
The Effect of Solid Concentration on the Secondary Air-Jetting Penetration in a Bubbling Fluidized Bed
,”
Powder Technol.
,
185
(
2
), pp.
164
169
.
6.
Müller
,
C. R.
,
Holland
,
D. J.
,
Davidson
,
J. F.
,
Dennis
,
J. S.
,
Gladden
,
L. F.
,
Hayhurst
,
A. N.
,
Mantle
,
M. D.
, and
Sederman
,
A. J.
,
2009
, “
Geometrical and Hydrodynamical Study of Gas Jets in Packed and Fluidized Beds Using Magnetic Resonance
,”
Can. J. Chem. Eng.
,
87
(
4
), pp.
517
525
.
7.
Yang
,
W.-C.
,
1998
, “
Comparison of Jetting Phenomena in 30-cm and 3-m Diameter Semicircular Fluidized Beds
,”
Powder Technol.
,
100
(
2–3
), pp.
147
160
.
8.
Wang
,
F.
,
Yu
,
Z.
,
Marashdeh
,
Q.
, and
Fan
,
L.-S.
,
2010
, “
Horizontal Gas and Gas/Solid Jet Penetration in a Gas-Solid Fluidized Bed
,”
Chem. Eng. Sci.
,
65
(
11
), pp.
3394
3408
.
9.
Pore
,
M.
,
Holland
,
D. J.
,
Chandrasekera
,
T. C.
,
Müller
,
C. R.
,
Sederman
,
A. J.
,
Dennis
,
J. S.
,
Gladden
,
L. F.
, and
Davidson
,
J. F.
,
2010
, “
Magnetic Resonance Studies of a Gas-Solids Fluidised Bed: Jet-Jet and Jet-Wall Interactions
,”
Particuology
,
8
(
6
), pp.
617
622
.
10.
Guo
,
Q.
,
Si
,
C.
, and
Zhang
,
J.
,
2010
, “
Flow Characteristics in a Jetting Fluidized Bed With Acoustic Assistance
,”
Ind. Eng. Chem. Res.
,
49
(
16
), pp.
7638
7645
.
11.
Leu
,
L.-P.
,
Li
,
J.-T.
, and
Chen
,
C.-M.
,
1997
, “
Fluidization of Group B Particles in an Acoustic Field
,”
Powder Technol.
,
94
(
1
), pp.
23
28
.
12.
Guo
,
Q.
,
Liu
,
H.
,
Shen
,
W.
,
Yan
,
X.
, and
Jia
,
R.
,
2006
, “
Influence of Sound Wave Characteristics on Fluidization Behaviors of Ultrafine Particles
,”
Chem. Eng. J.
,
119
(
1
), pp.
1
9
.
13.
Kaliyaperumal
,
S.
,
Barghi
,
S.
,
Zhu
,
J.
,
Briens
,
L.
, and
Rohani
,
S.
,
2011
, “
Effects of Acoustic Vibration on Nano and Sub-Micron Powders Fluidization
,”
Powder Technol.
,
210
(
2
), pp.
143
149
.
14.
Levy
,
E. K.
,
Shnitzer
,
I.
,
Masaki
,
T.
, and
Salmento
,
J.
,
1997
, “
Effect of an Acoustic Field on Bubbling in a Gas Fluidized Bed
,”
Powder Technol.
,
90
(
1
), pp.
53
57
.
15.
Si
,
C.
, and
Guo
,
Q.
,
2008
, “
Fluidization Characteristics of Binary Mixtures of Biomass and Quartz Sand in an Acoustic Fluidized Bed
,”
Ind. Eng. Chem. Res.
,
47
(
23
), pp.
9773
9782
.
16.
Herrera
,
C. A.
, and
Levy
,
E. K.
,
2001
, “
Bubbling Characteristics of Sound-Assisted Fluidized Beds
,”
Powder Technol.
,
119
(
2–3
), pp.
229
240
.
17.
Heindel
,
T. J.
,
2011
, “
A Review of X-Ray Flow Visualization With Applications to Multiphase Flows
,”
ASME J. Fluids Eng.
,
133
(
7
), p.
074001
.
18.
Heindel
,
T. J.
,
Gray
,
J. N.
, and
Jensen
,
T. C.
,
2008
, “
An X-Ray System for Visualizing Fluid Flows
,”
Flow Meas. Instrum.
,
19
(
2
), pp.
67
78
.
19.
Escudero
,
D.
,
2010
, “
Bed Height and Material Density Effects on Fluidized Beds Hydrodynamics
,” M.S. thesis, Department of Mechanical Engineering, Iowa State University, Ames, IA, p.
109
.
20.
Escudero
,
D.
, and
Heindel
,
T. J.
,
2011
, “
Bed Height and Material Density Effects on Fluidized Bed Hydrodynamics
,”
Chem. Eng. Sci.
,
66
(
16
), pp.
3648
3655
.
21.
Drake
,
J. B.
, and
Heindel
,
T. J.
,
2011
, “
The Repeatability and Uniformity of 3D Fluidized Beds
,”
Powder Technol.
,
213
(
1–3
), pp.
148
154
.
22.
Drake
,
J. B.
, and
Heindel
,
T. J.
,
2012
, “
Comparisons of Annular Hydrodynamic Structures in 3D Fluidized Beds Using X-Ray Computed Tomography Imaging
,”
ASME J. Fluids Eng.
,
134
(
8
), p.
081305
.
23.
Escudero
,
D. R.
, and
Heindel
,
T. J.
,
2014
, “
Acoustic Fluidized Bed Hydrodynamics Characterization Using X-Ray Computed Tomography
,”
Chem. Eng. J.
,
243
(
0
), pp.
411
420
.
24.
Escudero
,
D.
, and
Heindel
,
T. J.
,
2013
, “
Minimum Fluidization Velocity in a 3D Fluidized Bed Modified With an Acoustic Field
,”
Chem. Eng. J.
,
231
, pp.
68
75
.
25.
Rees
,
A. C.
,
Davidson
,
J. F.
,
Dennis
,
J. S.
,
Fennell
,
P. S.
,
Gladden
,
L. F.
,
Hayhurst
,
A. N.
,
Mantle
,
M. D.
,
Müller
,
C. R.
, and
Sederman
,
A. J.
,
2006
, “
The Nature of the Flow Just Above the Perforated Plate Distributor of a Gas-Fluidised Bed, as Imaged Using Magnetic Resonance
,”
Chem. Eng. Sci.
,
61
(
18
), pp.
6002
6015
.
26.
Blake
,
T. R.
,
Webb
,
H.
, and
Sunderland
,
P. B.
,
1990
, “
The Nondimensionalization of Equations Describing Fluidization With Application to the Correlation of Jet Penetration Height
,”
Chem. Eng. Sci.
,
45
(
2
), pp.
365
371
.
27.
Wen
,
C. Y.
,
Deole
,
N. R.
, and
Chen
,
L. H.
,
1982
, “
A Study of Jets in a Three-Dimensional Gas Fluidized Bed
,”
Powder Technol.
,
31
(
2
), pp.
175
184
.
28.
Zhang
,
K.
,
Zhang
,
J.
, and
Zhang
,
B.
,
2003
, “
Experimental and Numerical Study of Fluid Dynamic Parameters in a Jetting Fluidized Bed of a Binary Mixture
,”
Powder Technol.
,
132
(
1
), pp.
30
38
.
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