浓相气力输送关键装置的开发及应用

发布时间：2018-07-04 13:45

本文选题：浓相气力输送 + 仓泵　；参考：《济南大学》2013年硕士论文

【摘要】：近年来，随着我国工业化进程的不断加快，人们环保意识的逐渐增强，在粉状物料的输送方面，具有自动化程度高、干净环保等优点的浓相气力输送技术得到了越来越多的应用，广泛应用于食品、电厂、建材、化工等制造业领域。在工程应用中，发送装置的选择和管道的布控是决定系统性能的重要因素，对输送的稳定性和连续性有决定性作用。本文针对浓相气力输送系统应用现状，选取较为常用的上引式流态化发送仓泵作为研究对象，通过优化设计，得出不同几何参数的输送仓泵系统，，进而确定最佳几何构型。以此为基础，搭建气力输送实验台，采用空气作为输送动力，脱硫石膏粉体作为输送物料，进行两相流实验，进而对不同几何结构下仓泵系统的流动特性进行研究，找出仓泵最优的几何构型。并且结合数值模拟技术研究仓泵内气固两相的流场信息，达到对输送仓泵的优化。论文首先设计并开发了具有代表性的上引式流态化仓泵，通过优化计算得到了较优的系统参数，并进行了设计制作。在此基础上搭建了密闭的、自动化效果良好的管道输送系统。此系统主要包括发送仓泵、输送管道、收料装置和各种测试设备。实验表明，系统能够正常运行。采用干燥的脱硫石膏粉作为输送物料，通过改变发送仓泵的内部几何结构、系统操作参数与系统参数，进行了系统的气力输送实验，并经过分析系统输送能力、管道压力降即能耗和系统稳定性这些因素，得到了内部最佳的几何构型。在最佳的仓泵构型基础上，通过对系统的输送能力、固相平均速度和系统能耗三个方面进行实验，发现随着表观气速的不断增加，系统的输送能力、固相平均速度和压力降也随之增加；随着固气比的增大，输送能力和压力降逐渐增大，但固相平均速度随之减小。并且结合数学方法建立了关于输送能力Gs和固相平均速度us的关联式，经过对比分析，发现误差较小。同时，论文采用数值模拟方法对发送仓泵内的流场信息及输送的动态特性进行了研究。得出了仓泵内气固两相运动的变化规律。模拟研究发现，仓泵内部发料过程两相运动较为复杂，极易出现物料的大量聚集；两相的速度矢量分布较为相似，矢量方向复杂多变，在两相与仓泵内壁相接触部位能够发生方向的改变；从颗粒速度流线图可得出，在靠近仓泵内壁处易形成大漩涡，在出料管附近易形成较小漩涡。同时，结合实验研究，与实验的设计参数相对应，模拟改变了仓泵内部几何构型。通过分析固相体积分布、固相速度矢量和颗粒速度流线图，对比分析了不同结构下两相流场的变化规律，达到对仓泵优化设计的目的。
[Abstract]:In recent years, with the acceleration of industrialization in China and the increasing awareness of environmental protection, there is a high degree of automation in the transportation of powdery materials. The dense phase pneumatic conveying technology with the advantages of clean and environmental protection has been applied more and more widely in the fields of food, power plant, building materials, chemical industry and so on. In engineering application, the selection of transmission device and the distribution and control of pipeline are the important factors that determine the system performance, and play a decisive role in the stability and continuity of transportation. In view of the present situation of application of dense phase pneumatic conveying system, the more commonly used updraft fluidized conveying bin pump is chosen as the research object. Through the optimization design, the conveying bin pump system with different geometric parameters is obtained, and the optimum geometric configuration is determined. On this basis, a pneumatic conveying test bench was built, air was used as conveying power, desulfurized gypsum powder was used as conveying material, and two-phase flow experiments were carried out, and the flow characteristics of silo pump system with different geometry were studied. Find out the optimal geometric configuration of the bin pump. Combined with numerical simulation technology, the flow field information of gas-solid two-phase in the tank pump is studied, and the optimization of the conveying bin pump is achieved. In this paper, a representative upfront fluidized bin pump is designed and developed. The optimal system parameters are obtained by optimizing calculation, and the system parameters are designed and manufactured. On this basis, a closed and automatic pipeline conveying system is built. This system mainly includes sending bin pump, conveying pipe, collecting device and various test equipment. The experiment shows that the system can run normally. The dry desulphurized gypsum powder is used as the conveying material. By changing the internal geometric structure of the delivery bin pump, the system operating parameters and system parameters, the pneumatic conveying experiment of the system is carried out, and the conveying capacity of the system is analyzed. The pressure drop, that is, energy consumption and system stability, is the best internal geometry. On the basis of the optimum configuration of bunker pump, through the experiments on the transportation capacity of the system, the average velocity of the solid phase and the energy consumption of the system, it is found that with the increasing of the apparent gas velocity, the transportation capacity of the system is increased. With the increase of solid-gas ratio, the transport capacity and pressure drop increased gradually, but the average velocity of solid phase decreased. The correlation between the transport capacity Gs and the average velocity of solid phase is established by combining the mathematical method. Through comparison and analysis, it is found that the error is relatively small. At the same time, numerical simulation method is used to study the information of flow field and the dynamic characteristics of transport. The change law of gas-solid two-phase motion in bin pump is obtained. The simulation results show that the two-phase motion is more complex and the mass accumulation of materials is easy to occur in the process of loading and unloading, and the velocity vector distribution of the two phases is similar, and the direction of the vector is complex and changeable. The direction of the two phase contact with the inner wall of the bin pump can be changed, and from the flow chart of particle velocity, it can be concluded that a large vortex is formed near the inner wall of the bin pump and a smaller vortex is easily formed near the discharge pipe. At the same time, according to the experimental design parameters, the simulation changes the internal geometry of the bin pump. Through the analysis of solid volume distribution, solid velocity vector and particle velocity streamline diagram, the variation law of two-phase flow field under different structures is compared and analyzed to achieve the purpose of optimizing the design of silo pump.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TH232

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