周帅帅1a,1b,1d,李 静1a,杨 浩1b,乔聪震1d,卢春喜2,张经纬1a,1c
(1.河南大学 a.纳米杂化材料应用技术国家地方联合工程研究中心;b.化学化工学院;c.纳米功能材料及其应用河南省协同创新中心; d.河南省催化反应工程中心,河南 开封 475000;2.中国石油大学(北京) 化学工程与环境学院,北京 昌平 102249)
DOI:10.13732/j.issn.1008-5548.2022.02.011
收稿日期: 2021-10-06,修回日期:2021-10-19,在线出版时间:2022-02-17 。
基金项目:NSFC-联合基金项目,编号:U2004176;河南省自然科学基金项目,编号:202300410063。
第一作者简介:周帅帅(1989—),男,讲师,博士,研究方向为过程强化。E-mail:10150173@vip.henu.edu.cn。
通信作者简介:
卢春喜(1963—),男,教授,博士,博士生导师,研究方向为过程强化。E-mail:lcx725@sina.com;
张经纬(1975—),男,教授,博士,博士生导师,研究方向为纳米材料工程。E-mail:jwzhang@henu.edu.cn。
摘要: 针对液相法石墨烯生产关键设备搅拌釜反应器,采用实验和模拟的方法对其内部多相复杂流场特性和规律进行研究。采用流体容积模型两相模型实现搅拌釜内多相流场的预测,并实验验证模型的适用性;采用计算流体动力学和离散元法建模耦合方法,计算片状颗粒在搅拌釜内的运动特性。结果表明:剪切速率在桨叶边缘及搅拌槽边壁附近区域较高,而颗粒主要集中于搅拌槽底部靠近边壁区域,并在底部形成颗粒堆积现象;单颗粒运动轨迹表明,非球形颗粒主体流动沿着流线方向,受底部颗粒堆积的影响,颗粒在运动过程中会在堆积区域停留较长时间;单颗粒受力结果分析发现,颗粒在运动过程中受搅拌桨和边壁的碰撞作用,会受到较大的脉冲力,而该合力持续时间较短,是颗粒运动轨迹改变的主要作用力。
关键词: 液相法;石墨烯;搅拌釜反应器;非球形颗粒;计算流体动力学;离散元建模
Abstract:The methods of experiment and simulation were used to reveal characteristcis of multi-phase complex flow field inside the stirred tank reactor,which was the key unit in graphere production by using liquied-phase method.Volume of fluent model of two-phase was used to predict the multi-phase flow field in the stirred tank,and suitability the model was verified by experimental results.Computational fluid dynamics-discrete element modeling coupling method was used to calculate the movement characteristics of the non-spherical particles in the stirred tank.The results show that the shear rate is much higher in the region near the edge of blades and the reactor wall,the particles are mainly concentrated in the region near the reactor wall at the bottom of the reactor,and the phenomenon of particle accumulation is formed at the bottom.The single particle trajectory shows that the main flow of non-spherical particles is along the streamline,and is affected by the accumulation of particles at the bottom.The particles will stay in the accumulation area for a long time during the movement.The forces exerted on the single particles show that the particles will be subjected to a larger pulse force due to the collision of the blades and the reactor wall during the movement,and the resultant force lasts for a short time,which is the main force for the change of the particle trajectory.
Keywords:liquid phase method;graphene;stirred tank reactor;non-spherical particle;computational fluid dynamics;discrete element modeling
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