振动筛不同运动形式对颗粒群筛分的影响

为研究不同运动形式振动筛的筛分性能,对平面往复、三移动一摆动、三移动两转动振动筛筛面上颗粒的分散程度进行分析和试验。基于颗粒非线性跳动理论,利用Matlab软件模拟得出颗粒在不同运动形式筛面上的运动状态;以分散度为试验指标,利用高速摄像机对玉米颗粒在3种振动平板上的运动进行跟踪。颗粒在振动平板上的运动规律证明了颗粒非线性跳动理论分析结果的正确性,随着振动筛主轴转速逐渐增大,颗粒群在3种振动平板上的分散度均呈现先增大、后减小的变化规律。在振动筛主轴最优转速下,玉米颗粒群在三移动一摆动、三移动两转动振动筛筛面上的综合分散度分别为38. 96 mm和40. 73 mm,较平面往复振动筛分别提高了14. 39%和19. 58%。以筛分效率为试验指标,利用3种振动筛筛面进行物料筛分试验,物料筛分试验结果表明,颗粒群在3种振动筛上的筛分效率由高到低依次为:三移动两转动振动筛、三移动一摆动振动筛、平面往复振动筛。物料筛分试验结果证明了用振动平板对颗粒群分散度进行研究的可行性,同时验证了平板试验结果的正确性。

Effect of Different Motion Forms of Vibrating Screen on Screening of Particle Group

Aiming to determine the screening performance of the vibration screen with different motion forms, the dispersion of particles on the plane reciprocating vibration screen, the vibration screen with three translations and one swing, and the vibration screen with three translations and two rotations were studied. Based on the nonlinear law of particle moving, the movements of particles on different screens with different motions were simulated by Matlab. The dispersity was taken as the experimental index. The motions of maize particles on three kinds of vibrating plate were tracked by high speed camera. The motion law of the particles on the vibration plate verified the correctness of the results of nonlinear law of particle moving based on theoretical analysis. The dispersity of the particles on the three kinds of vibration plates was increased firstly and then decreased with the increase of the spindle speed of the vibrating screen. At optimum rotating speed of the main shaft of the vibrating screen, the comprehensive dispersion of the maize particle group on the vibration plate with three translations and one swing and the vibration plate with three translations and two rotations were respectively 38.96mm and 40.73mm, which were 14.39% and 19.58% higher than that of the plane reciprocating vibration plate. The screening efficiency was taken as test index, and vibrating screens with three kinds of motions were tested for screening material. The results of material screening test showed that the screening efficiency of particle group on three kinds of vibrating screens from high to low was: the vibration screen with three translations and two rotations, the vibration screen with three translations and one swing and plane reciprocating vibrating screen. The results of material screening test verified the feasibility of studying the dispersion of particle group by using the vibrating plate and the correctness of the results. The research results provided references for the analysis of screening performance of the vibration screen with different motion forms and the design and application of the new vibration screen.