Simulation Study On Linear Vibrating Screen Using Discrete Element Method And Optimization On Vibration Parameters

Screening is an important technology for separation of particles according to their sizes. Screening process is a very complicated stochastic process.The most research of screening theory and screening technology depend on screen test but traditional screening test need to consume a large amount of human, material and financial resources, it wastes resources,so this paper mainly establishes the virtual prototype of vibrating screen to research screening process and screening efficiency numerical calculation with the help of computer. The key findings of this paper are as follows:Simulation studies of different shape particles vibration segregation process were carried out using3D DEM. it drawn a conclusion that spherical particles stratified fastest and triangle particles stratified slowest. Similar to the spherical particles had high screen-penetrating probability.Simulation studies of screening process of linear vibrating screen based on spherical granules were carried out using3D DEM. The observation is that screen underflow became slope type and the highest point was in the under of feeding. it was obvious that the fatigue breakages of screen often happened in the under of feeding.Simulation studies of different shape particles passing through different sieve pores process were carried out using3D DEM. it drawn a conclusion that the screen-penetrating probability passing through rectangle sieve pore is higher than sieve pore, the screen-penetrating probability passing through square sieve pore is higher than circle sieve pore under the same screen size conditions. From the number of different shape particles passing through different sieve pores aspect,long strip and flaky of particles were so easy to pass through rectangle sieve pore that it made the product particle size uneven.Simulation studies of how vibration parameters of vibrating screen affecting screening efficiency were carried out using3D DEM. Affection on screening efficiency was carried out by changing vibrating direction angle, inclination of screen deck, vibration frequency, amplitude these four vibrating parameters respectively.Simulation studies of20groups simulation experiments based on non-spherical particles granules were carried out using3D DEM for vibration parameters and screening efficiency relation fitting.The relation fitting between vibration parameters and screening efficiency was fitted based on simulation experimental data by Matlab in which called function "Regress" which applied to nonlinear regression analysis.The optimization design of how vibration parameters of vibrating screen affecting screening efficiency were analysed from the aspect of correlation coefficient, response curve, sensitivity and goal-driven optimization based on Design Exploration in Ansys Workbench12. On the whole the biggest impact factor for screening efficiency is the inclination of screen deck, the smallest is amplitude. Vibrating direction angle, inclination of screen deck and vibration frequency presented a negative correlation but amplitude presented a positive correlation for screening efficiency.In the condition of screening efficiency and throughput reaching optimum, optimal vibration parameters were got by goal-driven optimization.