基于脉动能量强化振动分选床中颗粒分离机制和数值模拟

发布时间：2018-06-27 19:02

本文选题：废弃催化剂 + 脉动能量　；参考：《中国矿业大学》2017年硕士论文

【摘要】：废弃催化剂中含有贵金属组分,回收废弃催化剂对资源的回收利用和环境保护具有重要的意义。本文以废弃催化剂为研究对象,研究了废弃催化剂的宏观密度组成,借助BT-2900动态图像分析仪得到物料的粒度组成。借助X射线衍射和X射线荧光光谱分析技术得到物料的成分及含量和元素组成,表明了物料含有贵金属Pt,含量达到0.156%,具有分选价值。根据废弃催化剂的密度差异,设计了脉动能量强化振动分选床系统。研究了物料在脉动能量强化下振动分选床中的受力平衡及动力学分析,揭示了物料在床体中的分离机理。采用CFD-DEM耦合技术,首先研究了脉动气流下颗粒的分离情况,表明了颗粒在倾斜分选床中仅受脉动气流的作用会存在堆积现象。模拟了不同密度球形颗粒的分离情况,表明了颗粒在分选床中主要基于密度进行分离。研究了振动和脉动气流复合力场下分选床中颗粒的运动情况和床体内部的流场变化。通过分析颗粒的运动情况,获得不同密度颗粒的速度、位移、和受力随时间的变化规律,表明了在气流和振动的协同作用下,不同密度颗粒能够有效分离。利用高速动态分析测试系统观察物料分别在脉动气流及其与振动作用下的分离情况,表明了试验现象和模拟结果相符。利用脉动能量强化振动分选床分选系统对废弃催化剂进行试验研究。考察了气流速度、脉动频率、倾斜角度和振动强度对废弃催化剂分选效率的影响,试验结果表明:废弃催化剂的综合效率随着气速、脉动频率、倾斜角度和振动强度的不断增加,呈现先增加后减小的趋势。在单因素试验的基础上,运用Design-Expert软件设计响应曲面试验,研究表明:气速为7.71m/s、脉动频率为3.8Hz、振动强度为10、倾斜角度为30鐜时,分选废弃催化剂的综合效率为97.36%。通过上述研究发现,新型脉动能量强化振动分选床较普通脉动气流分选床,不仅处理量增大,且分选物料易收集,可连续给料,具有重要的应用价值。
[Abstract]:The waste catalyst contains precious metal components, so the recovery of waste catalyst is of great significance to the recovery and utilization of resources and environmental protection. In this paper, the macroscopic density composition of the waste catalyst was studied, and the particle size composition of the waste catalyst was obtained by BT-2900 dynamic image analyzer. By means of X-ray diffraction and X-ray fluorescence spectroscopy, the composition, content and elemental composition of the material are obtained. It is shown that the material contains precious metal, the content of which is 0.156, which has the value of sorting. According to the density difference of the waste catalyst, the vibratory separation bed system with pulsating energy was designed. The mechanical balance and dynamic analysis of materials in vibratory separation bed under pulsating energy strengthening are studied. The separation mechanism of materials in bed is revealed. By using CFD-DEM coupling technique, the separation of particles in pulsating air flow is studied, which shows that there is a stacking phenomenon of particles in inclined separation bed only affected by pulsating airflow. The separation of spherical particles with different densities is simulated, which shows that the separation of particles in the separation bed is mainly based on density. The movement of particles in the separation bed and the variation of the flow field in the bed body under the combined force field of vibration and pulsating flow are studied. By analyzing the movement of particles, the changes of velocity, displacement and force with time of particles with different densities are obtained. It is shown that the particles with different densities can be separated effectively under the synergistic action of air flow and vibration. The high speed dynamic analysis and measurement system is used to observe the separation of materials under pulsating air flow and vibration respectively, which shows that the experimental phenomenon is in agreement with the simulation results. An experimental study on the waste catalyst was carried out by using pulsating energy enhanced vibratory separation bed separation system. The effects of flow velocity, pulsation frequency, tilt angle and vibration intensity on the separation efficiency of the waste catalyst were investigated. The experimental results showed that the comprehensive efficiency of the waste catalyst varied with the gas velocity and the pulsating frequency. The inclination angle and vibration intensity increase firstly and then decrease. On the basis of single factor test, the response surface test was designed by using Design-Expert software. The results show that when the gas velocity is 7.71 m / s, the pulsation frequency is 3.8 Hz, the vibration intensity is 10, and the inclination angle is 30 掳, the comprehensive efficiency of the waste catalyst is 97.36%. It is found that the new type pulsating energy enhanced vibratory separation bed is of great value in application because it not only increases the handling capacity, but also can be collected easily and can be continuously fed with the new type of pulsating energy enhanced vibratory separation bed compared with the ordinary pulsating flow separator.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X705;TD953

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