HE Zhaohui，SHI Yunlai，WANG Junhan，GUO Jiaxin

State Key Lab of Mechanics and Control for Aerospace Structures，Nanjing University of Aeronautics and Astronautics，Nanjing 210016，China

Abstract

Objective The screening efficiency of a vibrating particle size analyzer is a key indicator of its effectiveness in particle size separation. However， there has been limited research on the screening efficiency of small multi-layer circular vibrating screen particle size analyzers under different vibration parameters. This study investigates the impact of vibration frequency， amplitude，and other factors on the screening efficiency of quartz sand and river sand particles， aiming to identify the optimal vibration parameters that maximize particle screening efficiency and improve the energy utilization of the device.

Methods A small multi-layer circular vibrating particle size analyzer was designed， using mechanical vibrations to separate particles through six layers of standard circular sieves. The core functional module of the analyzer was the vibrating screening device， consisting of a voice coil motor as the vibration source， springs， a fixed base plate， and a top plate forming a complete vibration system. The voice coil motor offered the advantages such as fast response and convenient control， allowing parameter adjustments of vibration frequency and excitation force through a device drive controller. Rocky DEM simulation software was employed to simulate the screening process of quartz sand and river sand particles. Parameters such as vibration amplitude and frequency were adjusted in the motion settings of the software， while material properties of each structural part of the device and contact parameters between particles and the sieve， as well as between particles themselves， were configured in the software material database. The screening efficiency of particles on the first and sixth layers of the sieve under various amplitudes and vibration frequencies over a certain period was calculated， producing efficiency curves as a function of these parameters. Experiments were conducted by measuring the vibration amplitude of the voice coil motor under different excitation forces and frequencies using a laser vibrometer. Screening efficiency tests of quartz sand and river sand particles were then performed within the optimal frequency and amplitude ranges obtained from the simulation.