scholarly journals Application of the Discrete Element Method to Study the Effects of Stream Characteristics on Screening Performance

Minerals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 788 ◽  
Author(s):  
Ali Davoodi ◽  
Gauti Asbjörnsson ◽  
Erik Hulthén ◽  
Magnus Evertsson
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Relative Difference ◽  
Screening Process ◽  
Material Density ◽  
Screening Performance ◽  
Crushing Plant ◽  
Individual Particles ◽  
Element Method

Screening is a key operation in a crushing plant that ensures adequate product quality of aggregates in mineral processing. The screening process can be divided into the two sub-processes of stratification and passage. The stratification process is affected by the relative difference between various properties, such as particle shape, size distribution, and material density. The discrete element method (DEM) is a suitable method for analyzing the interactions between individual particles and between particles and a screen deck in a controlled environment. The main benefit of using the DEM for simulating the screening process is that this method enables the tracking of individual particles in the material flow, and all of the collisions between particles and between particles and boundaries. This paper presents how different particle densities and flowrates affect material stratification and, in turn, the screening performance. The results of this study show that higher density particles have a higher probability of passage because of their higher stratification rate, which increases the probability that a particle will contact the screen deck during the process.

Numerical simulation of particle screening efficiency of large multi-layer vibrating screen based on discrete element method

2021 ◽  
pp. 095440892110606
Author(s):  
Yujia Li ◽  
Peng Zhao ◽  
Li Mo ◽  
Tao Ren ◽  
Minghong Zhang
Keyword(s):  
Discrete Element Method ◽  
Environmental Protection ◽  
Inclination Angle ◽  
Discrete Element ◽  
Physical Parameters ◽  
Screening Process ◽  
Efficient Operation ◽  
Vibrating Screen ◽  
Screening Efficiency ◽  
Element Method

With the increasing requirements for energy conservation and environmental protection, multi-layer vibrating screens have become hot issues. Compared with single-layer vibrating screens, multi-layer vibrating screens has much better performance in terms of processing effect, treatment capacity, and environmental protection. The research on the physical parameters of the multi-layer vibrating screen is of great significance to the actual production. However, analysis and simulation studies of multi-layer vibrating screens are limited. In this paper, the screening process of wet particles on a multi-layer vibrating screen was simulated by using the discrete element method. The characteristics and application scope of the two vibration modes were analyzed. The particle penetration rate, the number of collisions, and the distribution of the particles under 23 combinations of structures and vibration parameters were investigated. The influence of different parameters on screening performance was analyzed. Several optimal combinations of frequency, amplitude and screen inclination angle under different working conditions were obtained. The screening efficiency of the balanced elliptic motion is higher than that of the linear motion. The best combination of the three parameters is 4 mm amplitude, 20 Hz frequency, and 3° inclination angle. The efficiency is higher when the particles follow a distribution of arithmetic on the screen. This study provides a reference for the efficient operation and optimal design of large multi-layer screening equipment.

scholarly journals Discrete Element Method Analysis of the Spreading Mechanism and Its Influence on Powder Bed Characteristics in Additive Manufacturing

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 392
Author(s):  
Valerio Lampitella ◽  
Marco Trofa ◽  
Antonello Astarita ◽  
Gaetano D’Avino
Keyword(s):  
Additive Manufacturing ◽  
Discrete Element Method ◽  
Ad Hoc ◽  
Low Cost ◽  
Discrete Element ◽  
Spreading Process ◽  
Powder Bed ◽  
Physical Phenomena ◽  
Element Method

Laser powder bed fusion additive manufacturing is among the most used industrial processes, allowing for the production of customizable and geometrically complex parts at relatively low cost. Although different aspects of the powder spreading process have been investigated, questions remain on the process repeatability on the actual beam–powder bed interaction. Given the influence of the formed bed on the quality of the final part, understanding the spreading mechanism is crucial for process optimization. In this work, a Discrete Element Method (DEM) model of the spreading process is adopted to investigate the spreading process and underline the physical phenomena occurring. With parameters validated through ad hoc experiments, two spreading velocities, accounting for two different flow regimes, are simulated. The powder distribution in both the accumulation and deposition zone is investigated. Attention is placed on how density, effective layer thickness, and particle size distribution vary throughout the powder bed. The physical mechanism leading to the observed characteristics is discussed, effectively defining the window for the process parameters.

Random Adjusted Calculation Method for 3D Aggregate of Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 13-16
Author(s):  
Yin Xu ◽  
Sheng Hong Chen
Keyword(s):  
Discrete Element Method ◽  
Calculation Method ◽  
Discrete Element ◽  
New Method ◽  
Computational Time ◽  
Concrete Aggregate ◽  
Analysis Tool ◽  
Advantages And Disadvantages ◽  
Element Method

Discrete element method is emerging as a useful numerical analysis tool for engineers interested in granular materials such as soil, concrete, or pharmaceutical powders. Simulated the concrete’s microscopic property and its impact on the macroscopic property by using particle discrete element method is one of the important research topics. Obviously, the first step in a discrete element simulation is the generation of the geometry of the system concerned, the quality of which will directly decide the quality of the simulation result. An integrated approach termed random adjusted calculation method is proposed in this paper after detailed analysis of the advantages and disadvantages of the existing aggregate delivery methods. The new method is a method which combined both the advantages of random method and non-geometry methods, such as hopper method and explosive repulsion method. Through out the analysis of the basic process of aggregate delivery and indicated by the result of the examples, random adjusted calculation method has the advantages of good overall density and easily controlled grading; and the computational time is smaller than the existing methods of non-geometry aggregate delivery; furthermore, the new method is easily carried out and provides a new idea for the delivery of concrete aggregate.

Banana Screening Method and Simulation of Banana Screening Process Using Discrete Element Method

2012 ◽  
Vol 524-527 ◽  
pp. 949-952
Author(s):  
Hai Lin Dong ◽  
Chu Sheng Liu ◽  
Yue Min Zhao ◽  
La La Zhao
Keyword(s):  
Discrete Element Method ◽  
Screening Method ◽  
Discrete Element ◽  
Structural Features ◽  
Constant Thickness ◽  
Screening Process ◽  
Ball Contact ◽  
Simulation Results ◽  
Velocity Changes ◽  
Element Method

This paper presented the fundamentals of banana screening method and the structural features of the banana screen. Based on soft-dry ball contact model, banana screening process was simulated by using 3D discrete element method. The results show that the material bed on banana screen possesses a characteristic of thin and constant thickness along the screen plate. The particles velocity on the screen deck shows a decreasing distribution along the screen deck length and the decrease of velocity changes from steep at the feed end to flat at the discharge end. The instantaneous efficiency of banana screen can reach to above 0.95 and the efficiency of steady state is about 0.83. Numerical simulation results can provide references for insight understanding of the banana screening mechanism and optimization of banana screen.

scholarly journals DEM Simulation of Spin Vibration Screening Process

2011 ◽  
Vol 2-3 ◽  
pp. 960-965
Author(s):  
Dong Sheng Li ◽  
Yi Qiong Du
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Motion Simulation ◽  
Screening Process ◽  
Dem Simulation ◽  
Simulation Results ◽  
Element Method

This paper focus on the motion simulation and visualization of the material particles in the operation of the spin vibration screening using DEM(Discrete Element Method). Based on analysis of the simulation results, some conclusions are made which provide the theory basis in order to design the screen parameters reasonably. Finally some experiments are carried out in order to verify the correctness of the simulation.

scholarly journals Application of the discrete element method (DEM) to particle laden multi-phase flows

2019 ◽  
Author(s):  
Harald Kruggel-Emden
Keyword(s):  
Discrete Element Method ◽  
Particle Interaction ◽  
Discrete Element ◽  
Flow Simulations ◽  
Fluid Systems ◽  
Computational Fluid Dynamics Cfd ◽  
Multi Phase ◽  
Boltzmann Method ◽  
Individual Particles ◽  
Element Method

The discrete element method (DEM) coupled with methods for computational fluid dynamics (CFD) is a very capable instrument to capture particle-laden multi-phase flows. While often the flow around individual particles is not resolved on the CFD-side particle interaction is captured in detail. More recently resolved flow simulations have gained in popularity which can be also based on the Lattice Boltzmann method (LBM). By coupling the latter with the DEM particle/fluid systems can even be studied in more detail. A brief review of both approaches is performed and possible applications are discussed.

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