Optimisation of a circularly vibrating screen based on DEM simulation and Taguchi orthogonal experimental design

Laboratory-scale validation of a DEM model of screening processes with circular vibration

A numerical study of the motion particulates follow along a circularly vibrating screen deck was done using the three dimensional Discrete Element Method (DEM). The motion of the particles was analyzed. The effects of vibration amplitude, throwing index, and screen deck inclination angle on the screening process are discussed. The results show that the average velocity of the particles increases along the longitudinal direction of the deck. The screening efficiency is highest when the vibration amplitude, throwing index, and screen deck inclination angle are 3–3.5 mm, 2.7 and 15°, respectively. This work is helpful for developing a deep understanding of particle motion and for optimizing screen separator designs.

Simulation of the screening process on a circularly vibrating screen using 3D-DEM

https://isiarticles.com/bundles/Article/pre/pdf/41636.pdf

Cuckoo search algorithm based on frog leaping local search and chaos theory

A review on the advanced design techniques and methods of vibrating screen for coal preparation

https://cyberleninka.org/article/n/973135.pdf

Dynamic design theory and application of large vibrating screen

Particle segregation processes in different vibration modes are simulated based on 3D discrete element method (DEM). The phenomena of wave motion of large particles in upper layer that appears in the segregation processes of linear vibration mode, accumulation and circulation that appear in circular and elliptical vibration mode are analyzed. And the influences of vibration intensity on the segregation pattern of the circular and elliptical mode were also discussed. The results show that the segregation behaviors in different modes can be well explained by a combination of three mechanisms: void filling, sidewall-driven transport of particles and nonequipartition of energy, and the distribution of particle velocity vectors. The vibration intensity has a great effect on the segregation pattern of circular and elliptical mode. For each vibration mode, fine particle segregation effect and stable particle moving state is obtained when the value of vibration intensity is about 3.

Numerical simulation of particle segregation behavior in different vibration modes

Basing on dry contact model of soft spheres the segregation processes of spherical and non-spherical particles were simulated using threes-dimensional discrete element methods（DEM）. Particle segregation mechanism was analyzed in view of force, torque and energy conversion between particles. Influence of segregation speed affected by particle size ratio was also discussed. The result shows that large particles are more active than small ones in segregation process, and non-spherical particles have higher energy, which makes up the influence of particle shape to segregation process to some extent, are more active than spherical particles. Average normal force, tangential force between large particles, their torque and kinetic energy are all greater than those of small particles. Particle segregation speed increases significantly with the increasing of size ratio. When the size ratio is greater than the critical value 3, the amplitude of increase in segregation speed will be slowed down.

Numerical simulation on segregation process of particles using 3D discrete element method

Discrete element method (DEM) simulations for pile-up processes of different particle systems were performed based on linear cohesion contact model. Effects of particle shape and liquid bridge force between wet particles on the piling form were analyzed. The significant central dip profiles of normal force acting on the base surface, normal force and tangential force between particles were predicted. Effects of particle shape and cohesion energy density on the forces on the base surface and inter-particles were described. The results show that particle shape and the liquid bridge force have significant impacts on the piling form. With the increase of the cohesion energy density the angle of repose for each granular pile increases. But the angle of repose of cubical particles is bigger than that of spherical particles under the same condition. Particle shape and the liquid bridge force also significantly affect the change and the maximum amplitude of the forces acting on the base surface and the forces between the particles. The maximum amplitude of the forces increases with the increase of the cohesion energy density, and the value of the maximum force on cubical particles is bigger than that on spherical particles. When the value of cohesion energy density is very large, the mechanical properties of granular piles become more complicated, so that the liquid bridge force has a larger impact on the packing characteristic of particles than the impact on particle shape.

Discrete element simulation of mechanical properties of wet granular pile

Shuffled Leaping Frog Algorithm(SFLA) is characterized by simplicity,few control parameters required,and easily be used,but has the disadvantages of premature convergence and low precision for hard high-dimensional optimization prob- lems,due to its rapid loss of the population diversity and the lack of local refined search abilities at the later stages of generations.In order to overcome the easy premature or early convergence of SFLAs,this paper hybridizes the SFLA and the Differential Evolution(DE) algorithm to form a hybrid optimization algorithm,namely SFL-DE,which borrows the idea from DE/best/1/bin strategy that has the advantages of strong global search ability and better population diversity.Comparisons are presented to test performances of the new algorithm employing 6 benchmark 30-dimensional functions.Compared with SFLA and standard DE(i.e.,DE/best/1/bin and DE/rand/1/bin schemes) algorithms,the experimental results in terms of the global optimization efficiency,the solution accuracy and the computation robustness demonstrate that the SFL-DE algorithm is a better tool for solving some benchmark optimization problems within a few fixed generations,but takes a longer run time.

Liu Chusheng

Papers

Dynamic design theory and application of large vibrating screen

Numerical simulation of particle segregation behavior in different vibration modes

Numerical simulation on segregation process of particles using 3D discrete element method

Discrete element simulation of mechanical properties of wet granular pile

Novel hybrid shuffled frog leaping and differential evolution algorithm