Study on screening probability model and particle-size effect of flip-flow screen

Flip-flow screening is an important method for classifying fine particles. As the lower limit of classification decreases during the screening process, the influence of particle-size characteristics becomes more significant. In this study, a laboratory prototype device of flip-flow screen (LPDFS) based on displacement excitation was built. Firstly, the screening probability model of flip-flow screening was established. The screening probability of particles was mainly determined by the average contact-mesh probability and screen-penetrating probability. On this basis, the screening experiment of LPDFS was explored under six different particle-size distributions. The function of the dominant particle-size fraction on screening effect was revealed. The influence mechanism of dispersion and average degree of each particle-size fraction on screening effect was explored. When the composition of the particle-size obeyed a normal distribution and with the increasing dispersion degree, the average particle-size fraction was at a distance from the near-screen particle-size, and the comprehensive separation index was higher. Further, highspeed photography was used to track the labeled particles. The throwing and loosening behavior of particle groups in the LPDFS was clarified.(c) 2022 The Society of Powder Technology Japan. Published by Elsevier BV and The Society of Powder Technology Japan. All rights reserved.