Numerical Simulation And Study On Swinging Screening

Screening is one of the common material separation methods in the industry.Through a vibration act on the materials, this makes the materials loosening,stratification, and penetration. Improving the two aspects is the purpose in thescreening operations. Thus, we are exploring a new vibration mode to increase thescreening performances.In this paper, the process of screening with the new vibrating mode was studiedbased on the discrete element method (DEM). The numerical simulation about theprocess of the new vibrating screen has been done to analyze the effects of thevarious parameters. The main works are as follows:1. Based on the Hertz-Mindlin collision model, established the discrete elementmethod screening model of spherical particles for the new vibrating mode; obtainedthe motion equation of the screen surface and analyzed the particle movement on thesurface.2. With single-factor test, the influence of swing parameters, structural parameters,and process parameter on the screening efficiency was analyzed. Mathematicalrelationship between the screening parameters and screening efficiency was fittedwith the least squares method. Furthermore, compared the screening performance ofthe swing mode to conventional linear vibration mode based on the numericalsimulation, which show that the performance of swing mode better than the linearvibration mode.3. The process of stratification and penetration was defined for the swingingscreen. Taken the fine ratio as the starting point, profoundly discussed the fine ratiosof stratification and penetration changed with the screen length, equip-distancescreen length and time. Fitting the experimental data and obtained the functionalmodels of stratification fine ratios and penetration fine ratios. Moreover, thestratification rate and penetration rate was proposed and the formulas of them wasobtained, which help us to understand the phenomenon of stratification andpenetration. This also guides the future optimization. 4. The blinding mechanism was roughly explored with the swing screen, whichstated the relationship between the collision frequency of different particle size andthe blinding. By counting the number of blinding particles, the size of particleswhich easily lead to blinding was analyzed. Furthermore, the relationships betweenscreening parameters and blinding have been explored.5. The results between the simulation of the linear vibration and industrialexperiments show that the parameters affect on the screening efficiency with DEMsimulation are consistent with the practice experiments. Therefore, the paper studythe process of swinging and screening mechanism with the discrete element methodis reasonable. It is effective to explore the characteristics and law of the singingscreen. These also provide the ideas and methods when designing the swingingscreen and exploring other new vibrating screen.