当前位置:
X-MOL 学术
›
Powder Technol.
›
论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
The mechanism of vibrations-aided gravitational flow with overhanging style in hopper
Powder Technology ( IF 5.2 ) Pub Date : 2018-03-01 , DOI: 10.1016/j.powtec.2017.12.077 Chunyang Zhang , Caimou Qiu , Chengzhi Pu , Xiang Fan , Ping Cao
Powder Technology ( IF 5.2 ) Pub Date : 2018-03-01 , DOI: 10.1016/j.powtec.2017.12.077 Chunyang Zhang , Caimou Qiu , Chengzhi Pu , Xiang Fan , Ping Cao
Abstract Arching, blocking, and sticking might be frequently encountered in hopper. Studies are carried out in order to solve these problems in Luoyang Bauxite Mine, China. The results of similarity model tests show that factors affecting flowability of particles are mainly friction and cohesion, when the moisture content changes from 8.2% to 10.8%, the influence of friction and cohesion on the flowability of particles becomes increasingly unfavorable, particles are easier to stay in the corners. In addition, the discharge effect is also affected by friction coefficient of the inner wall. In the numerical simulation, vibration is imposed by means of two blue balls fixed in the corners, where the flowability of particles is proved to be the worst. Results indicate that, no matter whether vibration is added or not, the total numbers of discharged particles and contacts change linearly with time steps, the contact forces between particles and walls are generally greater than that between particles. Compared with gravity discharge, the average velocities of the particles are obviously increased with the help of vibrations, especially in the corners of the hopper. The contact forces between particles as well as between particles and walls are optimized, that is, larger fluctuations of the contact forces are exhibited periodically, mainly because the contacts are greatly damaged by vibrations, therefore, the possibility of arching is limited effectively. The results of the studies reflect the mechanism of vibrations-aided gravitational flow and provide a theoretical basis for the design of a new vibrator. In combination with flow characteristics of particles, influencing factors of particle flow and theory of granular mechanics, a new flow-aiding vibrator with overhanging style in hopper is designed. In field tests, it has been proved to be a safe and effective device for solving problems of arching, blocking and sticking.
更新日期:2018-03-01