粉体装袋扬尘的动态研究及除尘优化

发布时间：2018-07-04 20:38

本文选题：粉体扬尘 + 气固两相流　；参考：《江南大学》2017年硕士论文

【摘要】：近年来,随着粉体物料需求日益增加,由粉体生产、包装引起的粉尘污染日趋严重。特别在粉体充填包装中产生的大量粉尘,不仅磨损生产设备,影响包装精度,更伤害工人健康。本课题通过分析扬尘规律,优化设计粉体除尘系统。具体在理论分析和模拟仿真基础上分析粉体充填扬尘的影响因素以及控尘措施;计算粉尘颗粒收集条件;设计除尘罩及确定除尘参数。通过整合两种除尘方式,设计粉体充填包装工艺路线、工作循环图。本课题旨在分析粉体下落扬尘的一般规律及影响因素,为粉料包装除尘提供理论参考。论文研究的主要内容如下:(1)对本课题研究对象进行调研分析,确定主要研究内容。通过分析粉体包装过程中的实际扬尘情况与危害,并调研该行业的生产现状以及发展趋势,确定课题研究的目的和意义。在查阅文献和生产调研基础上,掌握国内外对粉体包装,扬尘处理方面的现状与进展;理清理论研究方法—气固两相的发展趋势;分析现有包装方法中除尘的理念和措施。在此基础上,明确了课题主要研究内容与课题开展方向。(2)对粉体充填扬尘理论的分析。从颗粒、粉体的基本物理特性展开分析,明确颗粒粒径、粒径分布以及粉体密度、流动性特点,分析颗粒密度与粉体密度的联系与区别,了解颗粒扬尘的基本产生条件。在此基础上根据粉体下落扬尘现象,分析颗粒与气流的作用过程,将其明确归纳为气固耦合作用。在此基础上,分析总结粉体扬尘的因素条件,特别针对粉体包装过程的扬尘提出颗粒密度、质量流量以及下落高度三个关键因素。最后,基于粉体扬尘理论,提出适于粉体充填包装的除尘系统构思。(3)除尘流场内颗粒的平衡条件及理论计算。根据气固两相中颗粒在流场内的受力理论,结合颗粒实际运动情况分析气流对颗粒的受力,场强对颗粒的受力以及其它一些作用力。分析气流与气压对颗粒作用的关系,发现气压现象本质由气流产生。通过预估颗粒受力的量级大小,分析紊流雷诺数对颗粒运动影响,给出抽气集尘时颗粒的受力上限、下限平衡方程。将方程整理、简化为气流速度和颗粒粒径为自变量对颗粒受力大小因变量的关系式。最后,通过MATLAB绘制平衡方程,分析抽气除尘的理论风速条件。(4)对粉体充填扬尘进行仿真模拟,分析影响因素。在气固两相理论基础上,分析仿真机理选取合适的仿真模型与计算条件。根据生产实际与国家标准建立粉袋模型,设置模型参数和仿真条件,并对模型网格进行无关性验证。在此基础上,分析颗粒密度、质量流量及下落高度对粉体下落充填扬尘的影响。以颗粒速度分布、颗粒驻留时间、气流速度分布以及颗粒分布占比等为基础分析了粉袋内颗粒与气流的实际作用情况。最终确定粉体下落产尘量最少的距离区间。(5)除尘系统优化设计。根据粉体除尘罩设置理论和粉体实际充填情况设计除尘罩。并建立除尘罩模型,设置仿真参数条件并模拟粉体除尘过程。通过颗粒速度分布、气流速度分布及颗粒分布占比探究合理风速。计算除尘功率,将得到的除尘参数整合,设计粉体除尘系统,并根据工艺路线绘制工作循环图。
[Abstract]:In recent years, with the increasing demand of powder material, the dust pollution caused by the powder production and packaging is becoming more and more serious. In particular, a large amount of dust produced in the packing and packing of powder is not only worn out to wear production equipment, but also affects the packaging precision and harm the workers' health. This subject is to optimize the dust removal system by analyzing the dust law. On the basis of analysis and Simulation simulation, the influence factors of dust filling and dust control and dust control measures are analyzed, the collecting conditions of dust particles are calculated, dust cover and dust removal parameters are designed. Through the integration of two kinds of dust removal methods, the process route of powder filling packaging and working cycle diagram are designed. The purpose of this topic is to analyze the general rule of dust falling. The main contents of the paper are as follows: (1) research and analysis of the subject of this subject, determine the main research content. Through the analysis of the actual dust situation and harm in the process of powder packaging, and investigate the production status and development trend of the industry, to determine the research topic. Objective and significance. On the basis of consulting literature and production research, we can grasp the status and progress of powder packaging and dust treatment at home and abroad, clarify the development trend of the theoretical research method - gas solid two phase, analyze the concept and measures of the dust removal in the existing packaging methods. On this basis, the main research content and the project development are clarified. (2) analysis of the theory of dust filling and dust. From the basic physical characteristics of particles and powders, the particle size, particle size distribution, powder density, fluidity characteristics, the analysis of the relation and difference between particle density and powder density are analyzed, and the basic conditions of particle dust are understood. Based on this, the dust phenomenon of the powder is lowered. The action process of particle and air flow is analyzed, and it is clearly summed up as gas-solid coupling effect. On this basis, the factors of powder dust are analyzed and summarized. In particular, three key factors, particle density, mass flow and falling height, are put forward. Finally, based on the theory of powder dust, powder filling bag is put forward. The design of the dedusting system. (3) the equilibrium conditions and theoretical calculation of the particles in the dust flow field. According to the theory of the force in the flow field in the two phase of the gas solid, the force of the air on the particles, the force of the field strength to the particles and some other forces are analyzed according to the actual movement of the particles. The relationship between the effect of air and pressure on the particles is analyzed. The present pressure is essentially generated by the air flow. By estimating the magnitude of the force of the particles, the influence of the turbulent Reynolds number on the particle motion is analyzed. The upper limit of the force and the lower equilibrium equation are given. The equation is arranged to simplify the relationship between the velocity of air flow and the particle size as the dependent variable on the size of the particles. Finally, through the equation, the relationship between the particle size and the particle size is simplified. The MATLAB balance equation is plotted and the theoretical wind speed conditions are analyzed. (4) the influence factors are simulated and the influence factors are analyzed. On the basis of the gas solid two phase theory, the suitable simulation model and the calculation conditions are selected for the simulation mechanism. The model parameters and imitation of the model are set up according to the production practice and the national standard. On the basis of this, the effect of particle density, mass flow and falling height on dust filling and dust is analyzed on this basis. The actual effects of particle velocity distribution, particle residence time, airflow velocity distribution and particle distribution ratio are analyzed on the basis of particle density, particle density, flow velocity distribution and particle distribution ratio. The optimum design of dust removal system is finally determined. (5) the design of dust removal system is optimized. Dust cover is designed based on the theory of dust dust cover setting and actual filling of powder. A model of dust cover is set up. The simulation parameters are set up and the process of dust removal is simulated. The distribution of particle velocity, distribution of air velocity and distribution of particles are carried out by the particle velocity distribution. Compared with exploring reasonable wind speed, calculating the power of dust removal, integrating the dedusting parameters, designing the dust removal system, drawing the working cycle diagram according to the technological route.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X701.2

【参考文献】