Effects of fine particle outlet on performance and flow field of a centrifugal air classifier

OBJECTIVE To investigate the influence of mesh type on numerical simulating the dispersion performance of micro-powders through a home-made tube. METHODS With the computational fluid dynamics (CFD) method, a powder dispersion tube was meshed in three different types, namely, tetrahedral, unstructured hexahedral and prismatic-tetrahedral hybrid meshes. The inner flow field and the kinetic characteristics of the particles were investigated. Results of the numerical simulation were compared with literature evidences. RESULTS The results showed that using tetrahedral mesh had the highest computational efficiency, while employing the unstructured hexahedral mesh obtained more accurate outlet velocity. The simulation results of the inner flow field and the kinetic characteristics of the particles were slightly different among the three mesh types. The calculated particle velocity using the tetrahedral mesh had the best correlation with the changing trend of the fine particle mass in the first 4 stages of the new generation impactor (NGI) (R2 = 0.91 and 0.89 for powder A and B, respectively). Conclusions Mesh type affected computational time, accuracy of simulation results and the prediction abilities of fine particle deposition.

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107 Application of digital holography in behavior measurement of fine particle in flow field(2)

The Proceedings of the Fluids engineering conference ◽

10.1299/jsmefed.2006._107-1_ ◽

2006 ◽

Vol 2006 (0) ◽

pp. _107-1_-_107-4_

Author(s):

Hideki TOMIOKA ◽

Hiroyuki HIRAHARA ◽

Masaaki KAWAHASHI

Keyword(s):

Flow Field ◽

Fine Particle ◽

Digital Holography

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Numerical Simulation of a Flow Field in a Turbo Air Classifier and Optimization of the Process Parameters

Processes ◽

10.3390/pr8020237 ◽

2020 ◽

Vol 8 (2) ◽

pp. 237 ◽

Cited By ~ 3

Author(s):

Yun Zeng ◽

Si Zhang ◽

Yang Zhou ◽

Meiqiu Li

Keyword(s):

Flow Field ◽

Process Parameters ◽

Production Efficiency ◽

Rapid Development ◽

Engineering Application ◽

Production Equipment ◽

Powder Materials ◽

Optimal Process ◽

Air Classifier ◽

Rotor Cage

Due to the rapid development of powder technology around the world, powder materials are being widely used in various fields, including metallurgy, the chemical industry, and petroleum. The turbo air classifier, as a powder production equipment, is one of the most important mechanical facilities in the industry today. In order to investigate the production efficiency of ultrafine powder and improve the classification performance in a turbo air classifier, two process parameters were optimized by analyzing the influence of the rotor cage speed and air velocity on the flow field. Numerical simulations using the ANSYS-Fluent Software, as well as material classification experiments, were implemented to verify the optimal process parameters. The simulation results provide many optimal process parameters. Several sets of the optimal process parameters were selected, and the product particle size distribution was used as the inspection index to conduct a material grading experiment. The experimental results demonstrate that the process parameters of the turbo air classifier with better classification efficiency for the products of barite and iron-ore powder were an 1800 rpm rotor cage speed and 8 m/s air inlet velocity. This research study provides theoretical guidance and engineering application value for air classifiers.

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Turbo air classifier guide vane improvement and inner flow field numerical simulation

Powder Technology ◽

10.1016/j.powtec.2012.03.026 ◽

2012 ◽

Vol 226 ◽

pp. 10-15 ◽

Cited By ~ 24

Author(s):

Qiang Huang ◽

Jiaxiang Liu ◽

Yuan Yu

Keyword(s):

Numerical Simulation ◽

Flow Field ◽

Guide Vane ◽

Air Classifier

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Effect of rotor cage's outer and inner radii on the inner flow field of the turbo air classifier

Materialwissenschaft und Werkstofftechnik ◽

10.1002/mawe.201900145 ◽

2020 ◽

Vol 51 (7) ◽

pp. 908-919

Author(s):

Y. Yu ◽

X. Kong ◽

J. Liu

Keyword(s):

Flow Field ◽

Air Classifier

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107 Application of digital holography in behavior measurement of fine particle in flow field(1)

The Proceedings of the Fluids engineering conference ◽

10.1299/jsmefed.2006._107-a_ ◽

2006 ◽

Vol 2006 (0) ◽

pp. _107-a_

Author(s):

Hideki TOMIOKA ◽

Hiroyuki HIRAHARA ◽

Masaaki KAWAHASHI

Keyword(s):

Flow Field ◽

Fine Particle ◽

Digital Holography

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Numerical Study of Classification of Ultrafine Particles in a Gas-Solid Field of Elbow-Jet Classifier

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2005-77059 ◽

2005 ◽

Author(s):

Shibin Liang

Keyword(s):

Flow Field ◽

Ultrafine Particles ◽

High Speed ◽

Numerical Study ◽

Experimental Results ◽

Speed Flow ◽

Fluent Software ◽

Air Classifier ◽

Different Diameters

Computational fluid dynamics (CFD) is applied to develop a novel submicron air classifier. Based on different inner structure sizes and positions in the elbow-jet classifier, the two-dimensional air flow field has been simulated by the Fluent software. The Coanda-effect plays a paramount role in the separation of ultrafine particles in the high-speed flow field of the elbow-jet classifier. The effects on the features of the Coanda element, i.e. a half-cylinder, have been analyzed and discussed. The trajectories of moving particles with different diameters in the channels and chambers of the classifier have been calculated under the velocity field simulation results obtained by the CFD analysis. The cut sizes of three products at the related outlets of the classifier are obtained based on the trajectories calculation of the particles and compared with the corresponding experimental results. The ground/classified experiment has been conducted by using the products outlet of a vortex jet mill as the particles feed of the elbow-jet classifier. The experimental results show that the external classifier for the vortex jet mill improves the classification of the mill significantly. The combination of the vortex jet mill with the external classifier provides a new choice of the grinding equipment for the multiple size products of fine/medium/coarse powders. A centrifugal channel has been added between the vortex jet mill and the elbow-jet classifier to improve the performance of the air classifier. Both numerical and experimental results show that the pre-distributed feed powders at the exit of the centrifugal channel have a strong effect on the fine powders separation and a less effect on the coarse powders separation.

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