摘要：近年来我国粉尘爆炸事故越加频繁，特别是机械加工企业中由沉积粉尘扬起造成二次爆炸带来了巨大的生命财产损失。有鉴于此，此课题探究沉积粉尘（铝合金粉尘）在水平管道中的爆炸。运用粉尘云着火温度测试仪、风管爆炸试验平台和PIV粒子图像测试系统等研究粉尘在风管内的运动规律。61894

通过研究沉积颗粒物在水平风管的二次卷扬运动，得出在弱激波卷扬粉尘实验装置中膜片的存在与否、沉积颗粒物的量及其沉积的位置和高压气罐内的压力量对沉积颗粒物二次扬起有着很大的影响：在其他条件不变的情况下经过来流的作用无膜时粉尘的剩余量远远小于在相同沉积量下有膜的剩余量；沉积颗粒物在膜前是更容易被来流卷扬形成爆炸粉尘云。

通过PIV粒子图像测试系统成功地捕捉到水平除尘风管中沉积颗粒物被来流弱激波二次扬起后的气固两相流运动状态以及颗粒物粉尘云的分布结构；得出在高压气罐内压力较小情况下不论粉尘沉积量如何变化在水平除尘风管中颗粒物的运动均是属于层流运动，但当高压气罐内压力超过某个值时文中压力超过为0.2MPa，在颗粒物沉积了很小时颗粒物卷扬后的流动为层流但是当颗粒物沉积量达到一定值时文中为1g，卷扬后的流场变为湍流运动从而使除尘风管中的粉尘云分布更加均匀容易形成爆炸粉尘云。

毕业论文关键词：粉尘爆炸，除尘管道，弱激波，PIV测试系统

Analysis and calculation the movement of the dust in the air duct

Abstrarct: In recent years , dust explosion accidents has become increasingly frequent in China, especially by dust layers raised by secondary explosion brought huge loss of life and property of mechanical processing enterprises. In view of this, this topic explore the explosion of dust layers (aluminum alloy dust) in the horizontal pipe. The motion law of dust in the duct is studied by the dust cloud ignition temperature tester, the duct explosion test platform and the PIV particle image testing system and so on.

Through the study of secondary winding movement of particle deposition in the horizontal duct, it is concluded that the existence of the diaphragm, deposit the amount of particulate matter, The location of the particle sedimentation and High pressure air tank pressure strength has a great influence in the sedimentary particle secondary spread: the residual amount of dust is far less than the residual amount of membrane under the same deposition after flow to film in the other conditions remain unchanged; particle deposition is easier to be the explosion dust cloud by incoming flow winch in front of the membrane.

It is successfully to capture the gas-solid two-phase flow motion state of sediment particles are deposited in the level of dedusting duct to flow two weak shock after the rise and the distribution structure of particles of dust clouds through the PIV particle image testing system; No matter how dust deposition quantity changes ,particle movement are belongs to laminar flow movement in the horizontal dedusting duct under the condition of the high pressure air tank pressure is small. But when high pressure air tank pressure exceeds a value, the pressure is more than 0.2MPa. the particle deposition is very small, particulate matter hoist flow is laminar flow. But when the particle deposition amount reaches a certain value,or 1g, The flow field after winding becomes turbulent motion, so that the distribution of dust clouds in the dedusting duct is more balance and easy to form explosive dust cloud.

KeyWords：dust explosion; dust removal pipeline;weak shock；PIV test system

1 绪论 1

1.1 课题背景 1

1.2 国内外粉尘颗粒物运动特性研究现状