Study On Screen Surface Shape And Screening Parameters Optimization Of The Curved Screen

Vibration screen is the most widely used screening facility in modern industry and the actual production process will be directly affected by screening performance.So far in the research of vibrating screen,the screening performance is mainly improved by optimizing the parameters of screening facility.However,few studies on the shape of the screen surface have been done.As the most common vibratory screening equipment in industry today,the banana screen still lacks sufficient theoretical arguments in its shape which can be referred to as the inclination angle of each screen plate.Therefore,a new curved screen with better screening performance can be developed by the study on the shape of screen surface.In this paper,a method was proposed to optimize the shape of the screen surface based on the discrete element method(DEM).The superiority of screening performance of the new curved screen was verified both by numerical simulation and the prototype experimental platform.Also,the relationships between screening parameters and the screening performance of the new curved screen was studied.The main research contents are as follows:(1)A three-dimensional screening model was built based on DEM.The unittime screening efficiency was defined to describe the screening performance.Besides,a stepwise design method was proposed to study the screen surface shape and a new type of curved screen surface was developed.Also the reliability of the stepwise design method was explored at the same time.(2)Based on numerical simulation using EDEM software and experimental prototype platform,the superiority of the new curved screen was verified by the comparison with self-adjusted screen and three other screens with different screen shapes which have strong screening performance.And the screening advantages of new curved screen were explored preliminarily.(3)Based on numerical simulation by single-factor test,the relationships between the unit-time screening efficiency of the new curved screen and different structural parameters including opening percentage,ratio of particle size to pore size and screen width were studied,as well as vibration parameters which include amplitude,vibration frequency,and vibration direction angle.Also their mathematical models were established.(4)Orthogonal test was designed in order to discuss the significance of screening parameters of the new curved screen and explore the combination of the optimal parameters.