制备纳米碳酸钙的公转自转填充床研究

发布时间：2018-02-13 15:48

本文关键词： 超重力填充床纳米碳酸钙试验台模态分析优化布局　出处：《太原科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：超重力填充床目前已在纳米材料的合成、废水处理、气体净化等方面得到了广泛的应用,并且已经显示出很大的经济价值和广阔的发展潜力。传统的超重力填充床中存在如下问题。问题一:分散传质作用区很薄,原因在于液相接触填料前区很薄的几层内即被全部捕获,即流体和填料相对速度为零,分散作用即消失。尤其填料床内涉及两组份以上液相的流体反应时,对分散传质要求更高,问题更严重;问题二:有限的填料层厚度直接决定了液相贯穿填料的历程太短。历程太短又缩短了可调控的化学反应参与时间,影响最终反应效果。因此需要对传统填充床的进行改进。本文提出一种新型的自转公转的旋转填充床,即在超重力填充床的基础上引入自转系统。自转系统的加入可以实现超重力的方向随时间的快速变动,效果其一有效拓展填料对液相与气相的径向分散传递,液相气相与填料始终保持一个较高的相对速度,加大了液相气相的破碎率,增强分散传质作用;其二增加液相与气相在填料中的总历程,有效的填料层厚度得到了数十倍的增长,增加了可调控的化学反应参与时间,进而增强了综合传质效果,非常有利于纳米碳酸钙的制备。本文着重进行了公转自转超重力试验台的设计与搭建。在搭建完成后的第一次试运行时,试验台有较大噪声,摆动严重,很大程度上影响了实验的进行。为了分析原因用SOLIDWORKS三维软件建立模型,并计算得出了试验台的质点位置。之后用ANSYS对试验台进行了模态分析;用ADAMS对试验台进行了运动仿真,并根据计算结果和仿真结果对试验台从优化布局和局域配重两方面进行改进。通过对比改进前后的试验台的模态和质点的位移,验证了试验台的改进效果。最后通过制备纳米碳酸钙来研究公转自转超重力填充床的分散传质效果,最终制得了粒径较小,颗粒分布均匀的纳米碳酸钙。本文提出的这种公转自转超重力填充床,对于纳米碳酸钙的制备和超重力技术的推广革新有一定的参考价值。
[Abstract]:High gravity packed bed has been widely used in the synthesis of nanomaterials, wastewater treatment, gas purification and so on. And has shown great economic value and broad potential for development. The traditional hypergravity packed bed has the following problems. The reason is that the thin layers of the liquid phase contact with the packing zone are completely captured, that is, the relative velocity of the fluid and the filler is zero, the dispersion will disappear, especially when the fluid reaction involving more than two liquid phases is involved in the packed bed, The second problem is that the limited thickness of the packing layer directly determines that the process of liquid phase penetration is too short. The process is too short and shortens the time to participate in the controllable chemical reaction. It is necessary to improve the traditional packed bed. In this paper, a new type of rotating packed bed with rotation rotation is proposed. That is to say, the rotation system is introduced on the basis of hypergravity packed bed. With the addition of the rotation system, the direction of hypergravity can change rapidly with time. The first effect is to effectively expand the radial dispersion transfer of filler to liquid and gas phase. Liquid phase and filler always maintain a relatively high relative speed, increase the breakup rate of liquid phase gas phase, enhance the dispersion mass transfer effect; second, increase the total process of liquid phase and gas phase in the filler, The effective packing layer thickness increases by tens of times, increases the time of the controllable chemical reaction participation, and further enhances the comprehensive mass transfer effect. It is very beneficial to the preparation of nanometer calcium carbonate. In this paper, the design and construction of the rotating rotation hypergravity test-bed are emphasized. In the first trial operation after the completion of the test bed, there is a great noise and the swing is serious. In order to analyze the reasons, the model is built with SOLIDWORKS software, and the particle position of the test-bed is calculated. Then the modal analysis of the test-bed is carried out with ANSYS, and the motion simulation of the test-bed is carried out with ADAMS. According to the results of calculation and simulation, the optimum layout and local weight of the test bed are improved. The modal and particle displacement of the test bed before and after the improvement are compared. Finally, the dispersion mass transfer effect of rotating rotation hypergravity packed bed was studied by preparing nanometer calcium carbonate, and the particle size was smaller. The proposed rotating supergravity packed bed has a certain reference value for the preparation of nanometer calcium carbonate and the popularization and innovation of supergravity technology.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ132.32;TQ051.1

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