Characterization of flow pattern of cohesive particles in gas-solid fluidized bed via axial distribution of particle motions

2020 ◽  
Vol 130 ◽  
pp. 103355
Author(s):  
Wangmin Lin ◽  
Keqin Wang ◽  
Yao Yang ◽  
Zhengliang Huang ◽  
Jingyuan Sun ◽  
...  
Keyword(s):  
Flow Pattern ◽  
Fluidized Bed ◽  
Axial Distribution ◽  
Cohesive Particles

Experimental characterization of the flow pattern in an annular fluidized bed

2008 ◽  
Vol 86 (3) ◽  
pp. 536-542 ◽  
Author(s):  
Anne Collin ◽  
Karl-Ernst Wirth ◽  
Michael Ströder
Keyword(s):  
Flow Pattern ◽  
Fluidized Bed ◽  
Experimental Characterization

Influence of Seeding Conditions on Initial Biofilm Development during the Startup of Anaerobic Fluidized Bed Reactors

1989 ◽  
Vol 21 (4-5) ◽  
pp. 157-165 ◽  
Author(s):  
F. Ehlinger ◽  
J. M. Audic ◽  
G. M. Faup
Keyword(s):  
Fluidized Bed ◽  
Future Development ◽  
Protein Concentration ◽  
Specific Activity ◽  
Fluidized Bed Reactor ◽  
Fluidized Bed Reactors ◽  
Support Material ◽  
Biofilm Development ◽  
Initial Biofilm

The characterization of the biofilm of an anaerobic fluidized-bed reactor was completed under standard conditions. The distribution of the fixed protein concentration depended on the level in the reactor. The protein concentration reached 1520 µg.g−1 of support at the top of the reactor and only 1200 µg.g−1 at the bottom after 504 hours of operation but the specific activity of the biofilm was 33×10−4 µM acetate.h−1.mg−1 proteins at the bottom and only 26×10−4 µM.h−1.mg−1 at the top. The efficiency of a fluidized bed reactor and the composition of the biofilm changed with an increase of the pH from 7 to 8.5 during the seeding of the support material. Future development of the biofilm and the specific activity of the support were affected.

Solids Flow Pattern in the Bottom Zone of a Rectangular Cross-Section Circulating Fluidized Bed

2003 ◽  
Author(s):  
Hong-Shun Li ◽  
Yi-Jun Wang ◽  
Shi-Ping Jin
Keyword(s):  
Flow Pattern ◽  
Fluidized Bed ◽  
Cross Section ◽  
Quartz Sand ◽  
Circulating Fluidized Bed ◽  
Rectangular Cross Section ◽  
Temperature Response ◽  
Cold Model ◽  
Hot Particles ◽  
Bottom Zone

Solids flow pattern in the bottom zone of a rectangular cross-section CFB was investigated by using hot particles as the tracer. The experiments were carried out in a cold model circulating fluidized bed. The riser has an inner cross-section of 0.3 m by 0.5 m and a height of 5.8 m. The solids were returned into the riser at a height of 0.75 m above the air distributor within an angle of about 40 degree. Quartz sand was used as the bed material. The hot particles were also quartz sand but with a little smaller size. Specially designed miniature electrically heating devices were installed flush with the inner bed wall or inside the bed. At each run, about 10–15 cm3 hot particles were slowly pulled into the bed. The temperature response around the device was measured with four copper-constantan thermocouples. Based on the experimental results, a 3-D core-annulus model describing the solids flow pattern in the bottom zone of the CFB riser is proposed.

Characterization of fluidized bed layer inversion in a 191-mm-diameter column using both experimental and CPFD approaches

2012 ◽  
Vol 80 ◽  
pp. 419-428 ◽  
Author(s):  
V. Vivacqua ◽  
S. Vashisth ◽  
G. Hébrard ◽  
J.R. Grace ◽  
N. Epstein
Keyword(s):  
Fluidized Bed

scholarly journals Estimative Model of Particle Flow Pattern in Fluidized Bed Based on Bubble Behavior.

1996 ◽  
Vol 22 (6) ◽  
pp. 1442-1449
Author(s):  
Nobusuke Kobayashi ◽  
Ryohei Yamazaki ◽  
Shigekatsu Mori
Keyword(s):  
Flow Pattern ◽  
Fluidized Bed ◽  
Particle Flow ◽  
Bubble Behavior

Contribution of hydrodynamic characteristics on the performance of an aerobic biofilm conical fluidized bed

2011 ◽  
Vol 63 (6) ◽  
pp. 1160-1167 ◽  
Author(s):  
D. Zhou ◽  
X. T. Bi ◽  
S. Dong
Keyword(s):  
Fluidized Bed ◽  
Microbial Population ◽  
Expansion Ratio ◽  
Hydrodynamic Characteristics ◽  
Internal Circulation ◽  
Axial Distribution ◽  
Biofilm Thickness ◽  
Cell Matrix ◽  
Bed Expansion ◽  
Conical Fluidized Bed

The performance of a conical fluidized bed (TFB) bioreactor, including the biofilm thickness, microbial space density, microbial cell matrix and its efficiency for COD degradation at a bed expansion ratio of 14 to 90%, was studied and compared with a cylindrical fluidized bed (CFB) bioreactor. The hydrodynamic characteristics of the TFB, especially the internal-circulation of bioparticles associated with its unique tapered geometry of the bed, created a much more uniform axial distribution of the bioparticles, leading to the formation of thinner and more compacted biofilms in the TFB compared to that in the CFB. The thinner biofilm in the TFB tended to be stable and possessed more than 6 times of microbial population density compared to the CFB. As a result, thinner biofilms in the TFB contributed to a higher COD removal efficiency, which remained at over 95% at operated expansion ratios, about 15 to 25% higher than that in the CFB.

scholarly journals Thermal regeneration of waste foundry phenolic sand in a lab scale fluidized bed

2018 ◽  
Vol 23 (1) ◽  
Author(s):  
Johny Anderson Severo ◽  
Regina Célia Espinosa Modolo ◽  
Carlos Alberto Mendes Moraes ◽  
Flávia Schwarz Franceschini Zinani
Keyword(s):  
Fluidized Bed ◽  
Regeneration Process ◽  
Process Conditions ◽  
Loss On Ignition ◽  
Molding Process ◽  
Partial Removal ◽  
Thermal Regeneration ◽  
Previously Treated ◽  
Regeneration Efficiency

ABSTRACT Improper disposal of sand used in molding processes after casting increases logistical costs and environmental impact because of the presence of the phenolic resin in its composition. The regeneration process of waste foundry phenolic sand (WFPS) aims to recycle this material. As mechanical regeneration methods are not efficient to guarantee 100% cleaning of the sand grains and their use again in the molding process, this work investigated the efficiency of a method of thermal regeneration of this type of residue that can be employed as a complementary procedure. A laboratory-scale fluidized bed reactor was designed and built to regenerate WFPS that was previously treated by a mechanical method. The methodology used to design and construct the fluidized bed prototype is described, as well as the characterization of the residual, the standard clean sand and the regenerated sand. The results of the thermal regeneration in the fluidized bed were very satisfactory with respect to the regeneration efficiency. For the nine process conditions tested, loss on ignition values were reduced when compared to standard clean sand. This study presents the advantages of a combination of two processes, mechanical and thermal regeneration, which allows to reduce the time and eventual temperature of resin removal due to the partial removal of the resin layer or its weakening during the mechanical regeneration process. Of the nine process conditions tested, six had loss on ignition values below the CSS. Thus, the thermal regeneration in the fluidized bed results was quite satisfactory in relation to the regeneration efficiency.

Experimental Characterization of a Swirl Stabilized MGT Combustor

2015 ◽  
Author(s):  
T. O. Monz ◽  
M. Stöhr ◽  
W. O’Loughlin ◽  
J. Zanger ◽  
M. Hohloch ◽  
...  
Keyword(s):  
Flow Field ◽  
Flow Pattern ◽  
Flame Stabilization ◽  
Main Stage ◽  
Exhaust Gas ◽  
Test Rig ◽  
Gas Emissions ◽  
Preheating Temperature ◽  
Exhaust Gas Emissions

A swirl stabilized MGT combustor (Turbec T100) was operated with natural gas and was experimentally characterized in two test rigs, a pressurized and optically accessible MGT test rig and an atmospheric combustor test rig. For the detailed characterization of the combustion processes, planar OH-PLIF and simultaneous 3D-stereo PIV measurements were performed in the atmospheric combustor test rig. Flow fields, reaction zones and exhaust gas emissions are reported for a range of pressure scaled MGT load points. Parameter studies on combustor inlet conditions (e.g. air preheating temperature, air and fuel mass flow rates and fuel split) were conducted in the atmospheric combustor test rig. From the parameters studies the fuel split between the pilot and the main stage and the air preheating temperature were found to have the biggest impact on the flame shape, flame stabilization and exhaust gas emissions. The measurements of the ATM test rig are compared with measurements of the pressurized MGT test rig with and without an optically accessible combustion chamber. Opened and closed conical flame and flow pattern were found in both test rigs. Reasons for the two flame and flow pattern are supposed to be the interaction of pilot stage combustion and flow field and the interaction of the dilution air with the combustion and the flow field. The results are discussed and compared with repect to a transferability of combustion characteristics from the ATM test rig to the MGT test rigs.

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