NUMERICAL STUDY OF CLASSIFICATION OF ULTRAFINE PARTICLES IN A GAS-SOLID FIELD OF ELBOW-JET CLASSIFIER

2010 ◽  
Vol 197 (7) ◽  
pp. 1016-1032 ◽  
Author(s):  
Shibin Liang
Author(s):  
Shibin Liang

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.


2019 ◽  
Vol 10 (1) ◽  
pp. 294-302
Author(s):  
N.S. Keita ◽  
A. Mehel ◽  
F. Murzyn ◽  
A. Taniere ◽  
B. Arcen ◽  
...  

2020 ◽  
Vol 25 (1) ◽  
pp. 150-157
Author(s):  
Fredy Leonardo Dubeibe ◽  
Guillermo Alfonso Gonzalez ◽  
Edgar Acosta

In the present paper, we perform a numerical study of the Sitnikov problem aiming to characterize the orbits of a variable mass particle (e.g., comet, rocket, asteroid or spacecraft) and determine the uncertainty in the prediction of the final state of the test particle. The classification of final states was done through the well-known exit basins, while the determination of the uncertainty was calculated using a new tool named Basin entropy. It is found that for small values of the initial mass of the test particle, the number of initial conditions leading to bounded orbits gets increased, thus reducing the uncertainty in the final states. The same behavior in uncertainty is observed for increasing values of the exponent in Jeans law for the variation of the mass. Our results allow us to conclude that: i) an accelerated fuel consumption in the initial stages of stabilization of a satellite can keep the object in an oscillatory state around the primaries and ii) if the mass of the satellite is less than one hundredth of the mass of each primary, it is possible to predict with a very high certainty the final state of the satellite, regardless of the accuracy in the initial conditions of the system.


2005 ◽  
Vol 23 (0) ◽  
pp. 173-181 ◽  
Author(s):  
Kazuya Wakabayashi ◽  
Sonoko Sekita ◽  
Hiroshi Hayashi ◽  
Hiroshi Sasaki

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