A discrete element method (DEM) simulation and experimental research on powder mixing process and stirring power

doi:10.16085/j.issn.1000-6613.2020-1509

Abstract

Abstract:

The mixing process, power and torque of straight blade impeller powder mixer were studied by combining numerical simulation with power test. The mixing process of spherical particles in the powder mixer was simulated by discrete element method (DEM). The effects of stirring speed, impeller diameter and blade number on the mixing power and torque were studied, and the power calculation formula was obtained by fitting. A powder mixing test-bed was built to test the power of powder mixing and compare with the simulation results. The results showed that the power consumption in the straight blade impeller powder mixer is closely related to the impeller speed, impeller diameter, blade number and other characteristic parameters. At the same time, torque value and power value were positively correlated with impeller speed, impeller diameter and blade number. The results showed that the torque speed relationship and power speed relationship were similar to the simulation, and the simulation values were in good agreement with the test ones, which verifies the accuracy of the derived formula.

Key words: powder, stirring power, torque, numerical simulation, DEM

摘要：

采用数值模拟与功率测试相结合的方法，研究直叶桨式粉体混合机搅拌过程及搅拌功率、扭矩的变化规律。对粉体混合机内球形颗粒的混合过程进行离散单元法DEM数值模拟，研究直叶桨式粉体混合机内搅拌转速、搅拌桨直径、桨叶数目等特性参数对粉体混合时搅拌功率和扭矩的影响，并拟合得到功率计算公式。搭建粉体搅拌试验台，测试粉体搅拌功率并与模拟结果比较。结果表明，直叶桨式粉体混合机内功率消耗与搅拌桨转速、搅拌桨直径、桨叶数目等特性参数有密切关系。同时，扭矩值和功率值与搅拌桨转速、搅拌桨直径和桨叶数目都呈正相关。实验得到了与模拟类似的扭矩-转速关系以及功率-转速关系，模拟值与测试值具有较好的吻合性，验证了所推导公式的准确性。

关键词: 粉体, 搅拌功率, 扭矩, 数值模拟, 离散单元法

CLC Number:

TQ027.1

XUAN Ying, LIU Xuedong, ZHOU Chengqi, LIU Wenming, LIU Hongmei, GU Yutong, PENG Tao. A discrete element method (DEM) simulation and experimental research on powder mixing process and stirring power[J]. Chemical Industry and Engineering Progress, 2021, 40(7): 3598-3607.

宣颖, 刘雪东, 周成奇, 刘文明, 刘红梅, 顾宇彤, 彭涛. 粉体混合过程及搅拌功率的DEM数值模拟和实验[J]. 化工进展, 2021, 40(7): 3598-3607.

Figures/Tables 15

References 18

1	BRIDGWATER J. Mixing of powders and granular materials by mechanical means: a perspective[J]. Particuology, 2012, 10(4): 397-427.
2	KUMARESAN T, JOSHI J B. Effect of impeller design on the flow pattern and mixing in stirred tanks[J]. Chemical Engineering Journal, 2006, 115(3): 173-193.
3	SHI Q, YAN X. Experimental study of segregation patterns in binary granular mixtures under vertical vibration[J]. Chinese Science Bulletin, 2003, 48(7): 627-629.
4	JIAN J, ZHONG F, XING M. The calculation method of mixing power[J]. Journal of Xi'an Highway University, 2000, 20(3): 98-100.
5	汪建峰, 王广全, 操伟伟, 等. 折流式旋转床有效功耗的初步研究[J]. 化工进展, 2016, 35(4): 1022-1026.
	WANG J F, WANG G Q, CAO W W, et al. Preliminary studies on the effective power consumption of rotating zigzag bed[J]. Chemical Industry and Engineering Progress, 2016, 35(4): 1022-1026.
6	张哲, 苏杨, 马宁, 等. 低填充比下混合滚筒粉体混合特性数值模拟[J]. 化工进展, 2017, 36(1): 114-120.
	ZHANG Z, SU Y, MA N, et al. Simulation of mixing characteristics of rotary drum with low packing ratio of powder[J]. Chemical Industry and Engineering Progress, 2017, 36(1): 114-120.
7	KAZENIN D A, CHEPURA I V. Hydrodynamics, mass transfer, and power consumption in air-core stirred tank reactors[J]. Theoretical Foundations of Chemical, 2008, 42(2): 118-124.
8	马青山, 冯连芳. 卧式单轴粉体搅拌反应器的搅拌功率[J]. 高校化学工程学报, 1999, 13(1): 31-37.
	MA Q S, FENG L F. Power consumption for powder in horizontal agitated reactor[J]. Journal of Chemical Engineering of Chinese Universities, 1999, 13(1): 31-37.
9	杨敏官, 冯浪, 康灿, 等. 偏心搅拌槽内颗粒悬浮特性的试验研究[J]. 水电能源科学, 2012, 30(4): 129-131.
	YANG M G, FENG L,KANG C, et al. Experimental study on critical suspension speed of shaft in eccentrically stirred tank[J]. Water Resources and Power, 2012, 30(4): 129-131.
10	SATO Y, NAKAMURA H, WATANO S. Numerical analysis of agitation torque and particle motion in a high shear mixer[J]. Powder Technology, 2008, 186(2): 130-136.
11	SIRAJ, SHAFIQ M. Single-blade convective powder mixing: the effect of the blade shape and angle[J]. Powder Technology, 2014, 267: 289-301.
12	REMY B, CANTY T M, KHINAST J G, et al. Experiments and simulations of cohesionless particles with varying roughness in a bladed mixer[J]. Chemical Engineering Ence, 2010, 65(16): 4557-4571.
13	BAO Y Y, LI T C, WANG D F, et al. Discrete element method study of effects of the impeller configuration and operating conditions on particle mixing in a cylindrical mixer[J]. Particuology, 2020, 49: 146-158.
14	CLEARY P W, SINNOTT M D. Assessing mixing characteristics of particle-mixing and granulation devices[J]. Particuology, 2008, 6(6): 419-444.
15	CUNDALL P A, STRACK O D L. A discrete numerical model for granular assemblies[J]. Geotechnique, 1979, 29(1): 47-65.
16	ROJEK J, LABRA C, SU O, et al. Comparative study of different discrete element models and evaluation of equivalent micromechanical parameters[J]. International Journal of Solids and Structures, 2012, 49(13): 1497-1517.
17	陈程, 刘雪东, 罗召威, 等. 旋转流化床粉体混合机混合效果数值模拟和实验验证[J]. 化工进展, 2018, 37(9): 3294-3302.
	CHEN C，LIU X D，LUO Z W, et al. Numerical simulation and experimental verification of mixing effect in rotating fluidized bed powder mixer[J]. Chemical Industry and Engineering Progress, 2018, 37(9): 3294-3302.
18	谢红笑, 刘雪东, 尹传忠, 等. 机械式高速混合机内部多粒径颗粒混合特性仿真[J]. 中国粉体技术, 2018, 24(2): 11-17.
	XIE H X, LIU X D, YIN C Z, et al. Numerical simulation of polydisperse particles mixing characteristics in a mechanical high speed mixer[J]. China Powder Science and Technology, 2018, 24(2): 11-17.

项目	泊松比μ	密度ρ/kg·m^-3	剪切模量G/Pa
颗粒	0.35	1200	8.9×10⁸
壁面	0.37	1200	8×10⁸

项目	泊松比μ	密度ρ/kg·m^-3	剪切模量G/Pa
颗粒	0.35	1200	8.9×10⁸
壁面	0.37	1200	8×10⁸

[1]	WANG Lele, YANG Wanrong, YAO Yan, LIU Tao, HE Chuan, LIU Xiao, SU Sheng, KONG Fanhai, ZHU Canghai, XIANG Jun. Influence of spent SCR catalyst blending on the characteristics and deNO _x performance for new SCR catalyst [J]. Chemical Industry and Engineering Progress, 2023, 42(S1): 489-497.
[2]	GUO Qiang, ZHAO Wenkai, XIAO Yonghou. Numerical simulation of enhancing fluid perturbation to improve separation of dimethyl sulfide/nitrogen via pressure swing adsorption [J]. Chemical Industry and Engineering Progress, 2023, 42(S1): 64-72.
[3]	SHAO Boshi, TAN Hongbo. Simulation on the enhancement of cryogenic removal of volatile organic compounds by sawtooth plate [J]. Chemical Industry and Engineering Progress, 2023, 42(S1): 84-93.
[4]	WANG Tai, SU Shuo, LI Shengrui, MA Xiaolong, LIU Chuntao. Dynamic behavior of single bubble attached to the solid wall in the AC electric field [J]. Chemical Industry and Engineering Progress, 2023, 42(S1): 133-141.
[5]	CHEN Kuangyin, LI Ruilan, TONG Yang, SHEN Jianhua. Structure design of gas diffusion layer in proton exchange membrane fuel cell [J]. Chemical Industry and Engineering Progress, 2023, 42(S1): 246-259.
[6]	YANG Yudi, LI Wentao, QIAN Yongkang, HUI Junhong. Analysis of influencing factors of natural gas turbulent diffusion flame length in industrial combustion chamber [J]. Chemical Industry and Engineering Progress, 2023, 42(S1): 267-275.
[7]	CHEN Lin, XU Peiyuan, ZHANG Xiaohui, CHEN Jie, XU Zhenjun, CHEN Jiaxiang, MI Xiaoguang, FENG Yongchang, MEI Deqing. Investigation on the LNG mixed refrigerant flow and heat transfer characteristics in coil-wounded heat exchanger (CWHE) system [J]. Chemical Industry and Engineering Progress, 2023, 42(9): 4496-4503.
[8]	LIU Xuanlin, WANG Yikai, DAI Suzhou, YIN Yonggao. Analysis and optimization of decomposition reactor based on ammonium carbamate in heat pump [J]. Chemical Industry and Engineering Progress, 2023, 42(9): 4522-4530.
[9]	ZHAO Xi, MA Haoran, LI Ping, HUANG Ailing. Simulation analysis and optimization design of mixing performance of staggered impact micromixer [J]. Chemical Industry and Engineering Progress, 2023, 42(9): 4559-4572.
[10]	YE Zhendong, LIU Han, LYU Jing, ZHANG Yaning, LIU Hongzhi. Optimization of thermochemical energy storage reactor based on calcium and magnesium binary salt hydrates [J]. Chemical Industry and Engineering Progress, 2023, 42(8): 4307-4314.
[11]	WU Ya, ZHAO Dan, FANG Rongmiao, LI Jingyao, CHANG Nana, DU Chunbao, WANG Wenzhen, SHI Jun. Research progress on highly efficient demulsifiers for complex crude oil emulsions and their applications [J]. Chemical Industry and Engineering Progress, 2023, 42(8): 4398-4413.
[12]	YU Junnan, YU Jianfeng, CHENG Yang, QI Yibo, HUA Chunjian, JIANG Yi. Performance prediction of variable-width microfluidic concentration gradient chips by deep learning [J]. Chemical Industry and Engineering Progress, 2023, 42(7): 3383-3393.
[13]	SHAN Xueying, ZHANG Meng, ZHANG Jiafu, LI Lingyu, SONG Yan, LI Jinchun. Numerical simulation of combustion of flame retardant epoxy resin [J]. Chemical Industry and Engineering Progress, 2023, 42(7): 3413-3419.
[14]	WANG Shuo, ZHANG Yaxin, ZHU Botao. Prediction of erosion life of coal water slurry pipeline based on grey prediction model [J]. Chemical Industry and Engineering Progress, 2023, 42(7): 3431-3442.
[15]	ZHOU Longda, ZHAO Lixin, XU Baorui, ZHANG Shuang, LIU Lin. Advances in electrostatic-cyclonic coupling enhanced multiphase media separation research [J]. Chemical Industry and Engineering Progress, 2023, 42(7): 3443-3456.