scholarly journals Kinetic Energy Calculation in Granite Particles Comminution Considering Movement Characteristics and Spatial Distribution

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 217
Author(s):  
Qing Guo ◽  
Yongtai Pan ◽  
Qiang Zhou ◽  
Chuan Zhang ◽  
Yankun Bi

Profound knowledge of the movement characteristics and spatial distribution of the particles under compression during the crushing of rocks and ores is essential to further understanding kinetic energy release law. Various experimental methods such as high-speed camera technology, the coordinate method, and the color tracking method were adopted to improve the understanding of particles’ movement characteristics and spatial distribution in rock comminution. The average horizontal velocities of the four size particles α, β, γ, and δ are statistically calculated. The descending order of the particles’ average velocity is γ, β, α, and δ. In comparison, the descending order of the particles’ kinetic energy is α, β, γ, and δ. Moreover, the contribution of α particles to the total kinetic energy exceeds 70%. The spatial distribution characteristics of coarse and fine particles show different results. The probability of fine particles appearing in the range closer to the center area is greater, while the position of large particles appears to be more random. The color tracking results show that super-large particles generated by crushing are on the specimen’s surface, while small particles are generally produced from inside. The above results indicate a connection between the particle generation mechanism, movement characteristics, and spatial distribution in the comminution process.

2011 ◽  
Vol 26 (6) ◽  
pp. 1183 ◽  
Author(s):  
Yiming Lin ◽  
Ruibin Xu ◽  
Lingfeng Li ◽  
Wei Hang ◽  
Jian He ◽  
...  

Author(s):  
Kevin F. Donchi ◽  
Einar Uggerud ◽  
Georg Hvistendahl ◽  
Peter J. Derrick

Author(s):  
Juanjuan Cai ◽  
Jing Xun ◽  
Xiangyu Ji ◽  
Yue Lei

Urban rail transit (URT) develops rapidly in modern cities, and its energy efficiency attracts extensive attention. The utilization of regenerative energy (URE) is an important method for energy-efficient operation of URT. Regenerative braking is an energy recovery mechanism that slows down a moving train by converting its kinetic energy into electric energy. The electric energy can be utilized for other trains to accelerate in a cooperative way. To take full advantage of the regenerative energy, an energy calculation method which considers regenerative braking power to optimize the timetable is proposed in this paper. First, four operating modes of URE are defined and an integer programming model is formulated. Second, a branch and bound algorithm is designed to solve the optimal timetable in different scenarios. Third, the model is evaluated based on the operation data from the Yanfang Line, Beijing Metro, China. For peak hours, the results illustrate that the proposed method can significantly improve URE by 73.7% compared with the original timetable. Also, URE can be improved by 46.3% for off-peak hours. Finally, the comparison between the proposed method and the method based on the kinetic energy theorem is given. The simulation results illustrate that the proposed method could increase URE by 29.7% and 9.9% for peak and off-peak hours scenarios, respectively, in comparison with the method based on the kinetic energy theorem.


Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 44
Author(s):  
Yi Ge ◽  
Zhenbo Tong ◽  
Renjie Li ◽  
Fen Huang ◽  
Jiaqi Yu

Respimat®Soft MistTM is a newly developed spray inhaler. Different from traditional nebulizers, metered-dose inhalers, and dry powder inhalers, this new type of inhaler can produce aerosols with long duration, relatively slow speed, and a high content of fine particles. Investigating the effect of the key geometric parameters of the device on the atomization is of great significance for generic product development and inhaler optimization. In this paper, a laser high-speed camera experimental platform is built, and important parameters such as the geometric pattern and particle size distribution of the Respimat®Soft MistTM are measured. Computational fluid dynamics (CFD) and the volume of fluid method coupled with the Shear Stress Transport (SST) k-ω turbulence model are applied to simulate the key geometric parameters of the device. The effects of geometric parameters on the spray velocity distribution and geometric pattern are obtained. The angle of flow collision, the sphere size of the central divider and the length and width of the flow channel show significant impacts on the spray atomization.


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