张珂, 高贵军, 段祯, 王彦, 杜靖永. 基于DEM的新型叠振筛参数对煤泥筛分的影响[J]. 煤炭学报, 2023, 48(S1): 392-400. DOI: 10.13225/j.cnki.jccs.2022.0790
引用本文: 张珂, 高贵军, 段祯, 王彦, 杜靖永. 基于DEM的新型叠振筛参数对煤泥筛分的影响[J]. 煤炭学报, 2023, 48(S1): 392-400. DOI: 10.13225/j.cnki.jccs.2022.0790
ZHANG Ke, GAO Guijun, DUAN Zhen, WANG Yan, DU Jingyong. Influence of parameters of new stacked vibrating screen on coal slime screening based on DEM[J]. Journal of China Coal Society, 2023, 48(S1): 392-400. DOI: 10.13225/j.cnki.jccs.2022.0790
Citation: ZHANG Ke, GAO Guijun, DUAN Zhen, WANG Yan, DU Jingyong. Influence of parameters of new stacked vibrating screen on coal slime screening based on DEM[J]. Journal of China Coal Society, 2023, 48(S1): 392-400. DOI: 10.13225/j.cnki.jccs.2022.0790

基于DEM的新型叠振筛参数对煤泥筛分的影响

Influence of parameters of new stacked vibrating screen on coal slime screening based on DEM

  • 摘要: 煤泥颗粒黏度高是筛分过程中易糊筛的重要原因之一,通过改变传统直线振动筛的结构可以更好地避免糊筛。针对煤泥黏度大、易糊筛的特点,提出了可以防止糊筛的新型叠振筛,并设计动、静筛条交错排列、相对运动的叠振筛结构;对卡在筛缝中的颗粒与黏结成坨块的煤泥在叠振筛与普通直线振动筛上的筛分过程进行受力分析与对比,研究了叠振筛的防糊筛原理;建立了三维仿真模型,并运用离散元软件模拟煤泥颗粒在叠振筛上的筛分过程。为提高叠振筛的筛分效果,基于DEM并利用Hertz-Mindlin with JKR黏结模型分析了振动参数(筛面负倾角、振动方向角、振幅、振动频率)对煤泥筛分效率和筛下物分布比例的影响。研究结果表明:筛面倾角在-1°~-5°,筛分效率随着筛面负倾角的增大先提高后降低,当筛面倾角为-4°,筛分效率最高;振动方向角在35°~55°,筛分效率随振动方向角的增大逐渐增大,但55°的筛分效率较50°提升并不明显;振幅在1.5~3.5 mm,筛分效率随振幅的增大逐渐增大,3.5 mm的筛分效率较3 mm提升并不明显,但会较大幅度提高振动强度;振动频率在14~24 Hz,筛分效率随振动频率的增大先提高后降低,当22 Hz时筛分效率达到最大,22 Hz下的筛分效率较20 Hz提升并不明显,但会较大幅度提高振动强度;筛面负倾角、振动方向角、振幅、振动频率的提升都会使筛面上煤泥层变厚;大多数情况下筛下的细小煤泥颗粒分布比例随筛面方向逐渐减小;筛面负倾角和振动方向角的改变对筛分效率影响较小,振幅和振动频率的改变对筛分效率影响更大。

     

    Abstract: The high viscosity of coal slime particles is one of important reasons why the sieve is easy to stick to screen during its screening process. By changing the structure of traditional linear vibrating screen, the sticking sieve can be better avoided. Aiming at the characteristics of high viscosity of coal slime and easy to stick to screen, a new type of stacked vibrating screen that can prevent the sticking screen was proposed,and the structure of the stacked vibrating screen with the staggered arrangement of dynamic and static screen bars and relative motion was designed. The force analysis and comparison of the sieving process of the particles stuck in the screen slits and the coal slime that had been bound into lumps on the stacked vibrating screen and the ordinary linear vibrating screen were carried out,and the principle of the anti-paste screening of the stacked vibrating screen was studied. The 3D simulation model was established. And the screening process of coal slime particles on the stack vibrating screen was simulated by using discrete element software. In order to improve the screening effect of stacked vibrating screen,based on the DEM and using the Hertz-Mindlin with JKR bonding model,the effects of vibration parameters(negative inclination angle of screen surface,vibration direction angle,amplitude,and vibration frequency)on the screening efficiency of wet slime and distribution proportion under the screen were analyzed. The research results show that the screening efficiency increases first and then decreases with the increase of the negative inclination of screen surface in the range of-1°——5°. When the negative inclination angle of screen surface is-4°, the screening efficiency is the highest. When the vibration direction angle is in the range of 35°-55°,the screening efficiency gradually increases with the increase of vibration direction angle,but the screening efficiency of 55° is not significantly improved compared with 50°. When the amplitude is in the range of 1.5-3.5 mm,the screening efficiency increases gradually with the increase of amplitude. The screening efficiency of 3.5 mm is not significantly improved compared with that of 3 mm, but the vibration intensity will be greatly improved. When the vibration frequency is in the range of 14-24 Hz,the screening efficiency first increases and then decreases with the increase of vibration frequency. When the vibration frequency is 22 Hz,the screening efficiency reaches the maximum. The screening efficiency at 22 Hz is not significantly improved compared with 20 Hz,but the vibration intensity will be greatly improved. The increase of the negative inclination angle of screen surface,the vibration direction angle,the amplitude and the vibration frequency will make the slime layer on the screen surface thicker. In most cases, the distribution ratio of fine slime particles under the screen gradually decreases with the direction of screen surface. The changes of the negative inclination angle of screen surface and the vibration direction angle have little effect on the screening efficiency,while the changes of the amplitude and vibration frequency have a greater effect on the screening efficiency.

     

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