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

2020 ◽  
Vol 51 (7) ◽  
pp. 908-919
Author(s):  
Y. Yu ◽  
X. Kong ◽  
J. Liu
Keyword(s):  
2017 ◽  
Vol 117 ◽  
pp. 139-148 ◽  
Author(s):  
Zhanpeng Sun ◽  
Guogang Sun ◽  
Xiaonan Yang ◽  
Yi Yuan ◽  
Qinglian Wang ◽  
...  

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 237 ◽  
Author(s):  
Yun Zeng ◽  
Si Zhang ◽  
Yang Zhou ◽  
Meiqiu Li

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.


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.


2021 ◽  
Vol 52 (7) ◽  
pp. 772-780
Author(s):  
Y. Yu ◽  
X. Kong ◽  
C. Ren ◽  
J. Liu ◽  
J. Liu
Keyword(s):  

2007 ◽  
Vol 178 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Lijie Guo ◽  
Jiaxiang Liu ◽  
Shengzhao Liu ◽  
Jinggang Wang

2008 ◽  
Vol 21 (8) ◽  
pp. 598-604 ◽  
Author(s):  
Yongguo Feng ◽  
Jiaxiang Liu ◽  
Shengzhao Liu

2008 ◽  
Vol 58 ◽  
pp. 59-67 ◽  
Author(s):  
Qing Liang Yang ◽  
Jia Xiang Liu ◽  
Yun Bo Zhou

The turbo air classifier is one of the most widely used equipment in powder classification. The complex flow behaviour inside it, however, prevents material experiments from providing information about its internal separation mechanisms. A study of the interaction of structural variables is therefore undertaken examining air flow behaviour, specifically the air flow between the blades of the rotor cage. The investigation of these flow field characteristics made use of the computational fluid dynamics (CFD) to simulate the air flow in the classifier. It was found that the inlet velocity of the turbo air classifier and the rotary speed of the rotor cage are two of the dominating, non-structural factors that affect velocity distributions in the region between the rotor cage blades. Once the inlet velocity settles, a critical rotary speed must be present to smoothen the flow field between the blades, resulting in an excellent classification performance. Three-dimensional velocity measurements of the region between the blades by laser Doppler velocimeter (LDV) were performed to test the results of the flow field simulation. This revealed that when inlet velocity is invariable, the velocity distributions in the region between the blades are at its most symmetric with the critical rotary speed of the rotor cage making it more favourable for classification. The velocity measurement results are likewise in good agreement with the results of the flow field simulation. Newly structured rotor cages are also simulated and compared with a conventional turbo air classifier, air flow in the newly structured model is smoother. The distributions of radial and tangential velocities are more symmetric and the trend of the rotating vortex between the blades attenuates, particularly when the rotary speed is high. The newly structured rotor cages can therefore achieve higher classification performances.


2006 ◽  
Vol 11 (4) ◽  
pp. 331-343 ◽  
Author(s):  
M. S. Alam ◽  
M. M. Rahman ◽  
M. A. Samad

The problem of combined free-forced convection and mass transfer flow over a vertical porous flat plate, in presence of heat generation and thermaldiffusion, is studied numerically. The non-linear partial differential equations and their boundary conditions, describing the problem under consideration, are transformed into a system of ordinary differential equations by using usual similarity transformations. This system is solved numerically by applying Nachtsheim-Swigert shooting iteration technique together with Runge-Kutta sixth order integration scheme. The effects of suction parameter, heat generation parameter and Soret number are examined on the flow field of a hydrogen-air mixture as a non-chemical reacting fluid pair. The analysis of the obtained results showed that the flow field is significantly influenced by these parameters.


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