ABSTRACT

Elastic screening methods are widely used in the classification of moist coal as they can overcome the problem of aperture blockage. However, the use of an equally inclined screen surface with balanced excitation facilitates material accumulation, worsening the screening performance. Here, a disequilibrium excitation structure was proposed to solve the accumulation problem, and its synchronization process was studied using a high-speed camera system. The spatial motion of the rigid-flex elastic screen surface along material flow direction was reconstructed using a vibration test system. The influence of disequilibrium excitation force coefficient (F_de) and relative vibration motor shaft span (l_vms) on the screening performance of moist coal was investigated. The results showed that the phase difference between the two eccentric rotors gradually decreased to 0 under the coupling effect of the electromechanical system, achieving synchronous stable operation. The spatial trajectories of different parts of the rigid-flex elastic screen surface were close to ellipsoidal, with the long axis of the ellipse decreasing along the direction of material flow. The screening efficiency showed a maximum and the total misplaced materials showed a minimum with increasing F_de and l_vms. The optimum screening efficiency of 86.35% and the corresponding total misplaced materials of 5.03% were achieved at F_de = 1.15 and l_vms = 40%. Compared to the equilibrium excitation structure, the elastic screening process was enhanced by the use of disequilibrium excitation, with the screening efficiency increasing by 3.20%.

摘要

弹性筛分方法广泛用于湿煤的分级，因为它们可以克服孔径堵塞的问题。然而，使用具有平衡激发的等倾斜筛面会促进材料积累，从而使筛分性能变差。在这里，提出了一种不平衡激发结构来解决积累问题，并使用高速相机系统研究了它的同步过程。使用振动测试系统重建刚柔弹性筛面沿物料流动方向的空间运动。不平衡激振力系数 ( F _de ) 和相对振动电机轴跨距 ( l _{vms ) 的影响}) 对湿煤的筛分性能进行了研究。结果表明，在机电系统的耦合作用下，两个偏心转子之间的相位差逐渐减小到0，实现了同步稳定运行。刚柔弹性筛面不同部位的空间轨迹接近椭圆体，椭圆长轴沿物料流动方向减小。随着F _de和l _vms的增加，筛选效率最高，总错位材料最低。在F _de  = 1.15 和l_vms  = 40%。与平衡激发结构相比，采用不平衡激发增强了弹性筛分过程，筛分效率提高了3.20%。