基于高精度沉积厚度检测方法的通风除尘管道粉尘沉积规律

为了对有爆炸危险存在的工矿场所的沉积粉尘厚度进行实时在线监测,同时调研发现针对工矿场所的通风除尘管道沉积粉尘厚度检测国内外尚属空白的现状。首先提出了一种高精度的沉积粉尘厚度实时在线检测方法,其核心是将粉尘的沉积质量检测转化为沉积厚度检测,并通过理论研究推导出粉尘沉积质量-粉尘沉积厚度的数学关系式,据此进行信号处理设计完成了该种检测方法。再完成了实验管道选择、粉尘粒径筛选、实验环境条件准备以及由定量发尘器、静电除尘器、压气泵、除尘风硐、风速测定仪、电脑控制台和变频风机等组成的实验系统。基于此实验系统与实验准备,首先实验验证了粉尘沉积质量-粉尘沉积厚度数学关系式的正确性,同时进行了误差实验,验证了该种检测方法的分辨率达到0. 01 mm,精度达到0. 07 mm,证明了该方法对沉积粉尘厚度的检测效果。然后,对除尘管道内粉尘颗粒物的受力情况进行了理论分析和研究,发现随着粉尘颗粒的粒径增大,颗粒所受的重力、拖拽力、Basset力和Saffman力作用逐渐明显。最后,基于此颗粒受力分析理论和实验系统,利用该种检测方法对通风除尘管道内的粉尘在不同风速和不同粒径下的沉积规律进行了研究,表明:随着除尘风速和颗粒粒径的增大,粉尘沉积率呈指数型降低和升高。文末,对管道内粉尘颗粒的沉积行为进行了原因分析,并给出了对现场除尘风速的设计建议。

Dust deposition law of ventilation dust removal pipeline based on a high precision deposition thickness detection method

In order to carry out a real-time on-line monitoring of the deposition dust thickness of industrial and mining sites with explosion hazard,the investigation found that the detection of dust thickness in the ventilation and dust removal pipelines of industrial and mining sites is still not available at home and abroad.In this paper,a high-precision real-time on-line detection method for detecting deposition dust thickness is proposed.The core of the method is to convert the deposition quality detection of dust into sediment thickness detection,and theoretically study the mathematical relationship between dust deposition quality and dust deposition thickness.According to this,the signal processing design completes the detection method.The experimental pipeline selection,dust particle size screening,experimental environmental conditions preparation,and experimental system consisting of a quantitative dust collector,an electrostatic precipitator,a gas pump,a dust removal wind,an anemometer,a computer console,and a variable frequency fan were completed.Based on the experimental system and experimental preparation,the experimental results verify the correctness of the mathematical relationship between dust deposition quality and dust deposition thickness.At the same time,the error experiment is carried out to verify that the resolution of the detection method reaches 0.01 mm and the precision reaches 0.07 mm.The detection effect of the method on the thickness of deposited dust is proved.Then,the theoretical analysis and research on the force of dust particles in the dust removal pipeline are carried out.It is found that with the increase of the particle size of the dust particles,the gravity,drag force,Basset force and Saffman force of the particles are gradually obvious.Finally,based on the theory and experimental system of particle force analysis,this method is used to study the deposition law of dust in the ventilation dust removal pipeline at different wind speeds and different particle sizes,which shows that with the dust removal wind speed and particle size,the increase in dust deposition rate decreases exponentially and increases.Also,the causes of the deposition of dust particles in the pipeline are analyzed,and the design suggestions for the dust removal velocity on the site are given.