Spatial–temporal evolution characteristics of surface and particles regulated by operating parameters during multi-stage variable inclination equal-thickness screening

Abstract

Multi-stage variable inclination equal-thickness screen (MSVIETS) is widely used in separating coal and mineral particles because of its large production capacity and good screening performance. In this study, the influence law of different operating parameters on the kinematic characteristics of infeed and outfeed ends surface and particles was investigated by using a high-speed camera analysis system. The spatial–temporal evolution process of screen surface and particles was revealed by Image-Pro Plus software. Screening experiments were used to verify the spatial and temporal distribution properties of the material. The operational parameters Ft, f and q all had a significant influence on the displacement. The displacement of the screen surface and particles at the infeed and outfeed ends during load operation increased to above 20 mm compared with that no load. The motion speed under load conditions was approximately five times higher than that under no load, which indicated that there was an energy transfer between the screen surface and particles. At T = 7.5 s, the overlap coefficient R-value was the largest according to image analysis software co-location analysis. This valued indicated the greatest effective utilization area of the screen surface. When the operating parameters were Ft = 6.43 kN, f = 34 Hz and q = 3 kg/s, the screening efficiency reached a maximum value at 94.41%. The total mismatched materials had a minimum value of 1.98%.