基于CFD的陶瓷静电施釉过程的关键技术研究

发布时间：2018-03-01 04:32

本文关键词： 静电施釉 CFD 数值模拟优化分析正交试验实验验证　出处：《景德镇陶瓷学院》2015年硕士论文　论文类型：学位论文

【摘要】：静电施釉技术具有施釉效果好、节省原料、提高釉浆利用率、降低陶瓷制品废品率、减少污染等优点,已得到广泛的认可。但是我国在陶瓷行业中,迟迟没有得到推广及应用,主要原因是对静电施釉设备原理及其雾化机理认识不足,对静电施釉各项重要工艺参数的选取优化的同时合理匹配等问题没有相关经验。针对以上问题,本文围绕静电施釉技术进行如下研究：(1)对静电施釉下电压放电机理及釉浆雾化机理进行了研究分析。基于流体力学CFD的流体连续性方程和动力方程进行分析,对釉浆在旋杯内的运动进行了研究,建立旋杯式静电施釉中釉浆在旋杯内运动及电场作用下对釉滴雾化影响的数学模型。(2)结合计算流体力学知识,对静电施釉系统进行建模,采用分区域划分网格技术,对雾化模型进行网格划分。利用DPM模型来模拟釉滴,通过MHD电磁场力程序,用UDS加入电的方程,然后利用UDF加入电场对动量方程的影响,从而通过FLUENT软件对静电施釉过程进行数值模拟分析。(3)分别对电压,釉浆压力,釉浆粘度这三个参数对静电施釉质量造成的影响进行模拟和分析,将得到静电施釉的釉滴群靠近陶瓷制品表面时的粒径分布和速度分布结果进行分析,分别得到在电压为-30KV时；釉浆压力为2.5bar;粘度为0.4Pa.s时,静电施釉质量较好。(4)利用数理统计中的正交试验法,对电压,供浆压力,釉浆粘度这三个参数对静电施釉的影响进行综合分析。然后分析了静电施釉雾场中这三个参数对指标因素进行正交分析,得到这三个参数影响静电施釉效果和效率的显著性,得到釉浆电压对静电施釉的影响电压最大,釉浆压力次之,粘度最小,得出了在电压为-50KV,釉浆压力为2.5bar,釉浆粘度为0.9Pa.s情况下,静电施釉的工艺参数配合好。(5)通过静电施釉实验对电压、供浆压力、釉浆粘度三个影响方面仿真结果进行验证,得到了在这三个工艺参数下,仿真和实验的结果趋势相似。从测得的釉粒平均粒径来看,分别得到电压为-30KV；供浆压力为1.91bar；釉浆粘度为0.6Pa.s时的粒径大小和粒径分布较好,最后综合三个工艺参数进行正交分析,得到最佳参数配合值(-30KV,1.91bar,0.6Pa.s)与仿真结果基本一致。本文模拟的结果为静电施釉过程的工艺参数合理选择奠定了理论基础,具有一定的参考价值。
[Abstract]:Electrostatic glazing technology has been widely recognized for its advantages of good glazing effect, saving raw materials, improving the utilization ratio of glaze slurry, reducing the waste rate of ceramic products and reducing pollution. However, in China, it has not been popularized and applied in the ceramic industry. The main reason is that the principle of electrostatic glazing equipment and its atomization mechanism are not well understood, and there is no relevant experience in selecting and optimizing the important technological parameters of electrostatic glazing at the same time as reasonable matching, etc. In view of the above problems, In this paper, the mechanism of voltage discharge under electrostatic glaze and the atomization mechanism of glaze slurry are studied and analyzed. Based on the fluid continuity equation and dynamic equation of hydrodynamics CFD, the following research on electrostatic glazing technology is carried out. In this paper, the movement of glaze slurry in rotary cup is studied, and the mathematical model of the influence of the slurry on the atomization of the glaze droplet under the action of the rotating cup and the electric field is established. The model of electrostatic glazing system is established by combining the knowledge of computational fluid mechanics. In this paper, the atomization model is meshed by using the technology of zonal grid division, the DPM model is used to simulate the glaze droplets, the electric equation is added by UDS through the MHD electromagnetic force program, and the influence of the electric field on the momentum equation is obtained by the addition of the UDF electric field. The effect of three parameters, such as voltage, slurry pressure and slurry viscosity, on the electrostatic glazing quality is simulated and analyzed by FLUENT software. The results of particle size distribution and velocity distribution of electrostatic glazed glaze droplets close to the surface of ceramic products are analyzed. The results show that when the voltage is -30 KV, the slurry pressure is 2.5 barand the viscosity is 0.4 Pa.s. The quality of electrostatic glazing is better. (4) by using the orthogonal test method in mathematical statistics, the voltage and slurry supply pressure are analyzed. The influence of these three parameters on electrostatic glazing is comprehensively analyzed, and then the orthogonal analysis of these three parameters in electrostatic glazing fog field is carried out, and the significance of these three parameters affecting the effect and efficiency of electrostatic glazing is obtained. The results show that the influence voltage of slurry voltage on electrostatic glazing is the greatest, the slurry pressure is the second, and the viscosity is the least. Under the condition of voltage -50 KV, slurry pressure 2.5 barand slurry viscosity 0.9 Pa.s, the results show that, when the voltage is -50 KV, the slurry pressure is 2.5 bar. and the slurry viscosity is 0.9Pa.s. The process parameters of electrostatic glazing are matched well. 5) through electrostatic glazing experiments, the simulation results of three aspects of voltage, slurry pressure and viscosity of glaze slurry are verified, and the results are obtained under these three technological parameters. The results of simulation and experiment are similar. According to the average particle size of glaze, the voltage is -30 KV, the supply pressure is 1.91 bar. the particle size and particle size distribution are better when the viscosity of glaze slurry is 0.6 Pa.s. finally, the three process parameters are analyzed by orthogonal analysis. The results of this paper provide a theoretical basis for the reasonable selection of the process parameters of electrostatic glazing process and have a certain reference value.
【学位授予单位】：景德镇陶瓷学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ174.641

【相似文献】