螺旋加料的粉体堆积密度检测方法及系统研究

发布时间：2018-06-10 15:52

本文选题：粉体堆积密度 + 电容传感器　；参考：《江苏大学》2017年硕士论文

【摘要】：在化工、食品加工、粉末冶金与农用物料等工农业生产中,螺旋加料机被广泛地应用于粉体的定量配料或包装。在加料过程中,螺旋输送管道内粉体堆积密度随工作条件环境变化而变化。及时获得螺旋加料机输送管内粉体堆积密度,对动态调节螺旋加料转速和转角,提高定量加料的准确性和定量加料效率,具有非常重要的价值和意义。依据螺旋加料装置实际结构,本文提出采用基于电容法的螺旋加料输送管内粉体堆积密度检测方法,研究其检测系统,主要研究内容和结果如下:首先,设计了粉体堆积密度电容传感器;分析了粉体堆积密度检测机理,推导出粉体堆积密度与传感器输出电容值之间数学关系,分析了粉体堆积密度影响因素;其次,利用有限元法建立传感器的仿真模型,基于COMSOLMultiphysics仿真软件对传感器输出性能仿真分析,探讨了传感器有无屏蔽罩、有无径向电极、电极极板张角、屏蔽罩半径、径向电极嵌入深度、检测电极极板厚度和螺旋轴叶片位置等对传感器输出性能的影响,优选了传感器结构参数,为传感器研制提供了理论基础。然后,基于MS3110芯片设计了粉体堆积密度电容传感器微弱电容检测电路,搭建了以MSP430F149单片机为核心的粉体堆积密度检测系统,设计了检测系统软件,对检测系统进行了整体调试。微弱电容检测的绝对误差为±0.0018pF,相对误差为±0.36%。最后,以干燥化处理后的小麦粉作为螺旋加料粉体,设计了粉体堆积密度检测标定装置,开展了粉体堆积密度传感器的标定试验、输出性能试验以及检测性能试验,得到:粉体堆积密度电容传感器输出电容与堆积密度之间非线性误差为±2.388%,检测灵敏度为3.131,检测输出电容的绝对误差为±0.0173pF,相对误差为±0.66%;检测系统对粉体堆积密度检测,检测值与实际值之间的绝对误差为±0.0188 g/cm3,相对误差为±3.11%。
[Abstract]:In the industrial and agricultural production of chemical industry, food processing, powder metallurgy and agricultural materials, screw feeder is widely used in the quantitative proportioning or packaging of powder. During the feeding process, the powder packing density in the spiral conveying pipeline varies with the working conditions. It is of great value and significance for dynamic adjustment of screw feeding speed and rotation angle to improve the accuracy of quantitative feeding and the efficiency of quantitative feeding to obtain the powder stacking density in the conveying pipe of screw feeder in time. According to the actual structure of the helical feeding device, this paper proposes a method based on capacitance method to detect the density of powder in the spiral feeding pipe, and studies its detection system. The main research contents and results are as follows: first of all, The measurement mechanism of powder packing density is analyzed, the mathematical relationship between powder packing density and the output capacitance of sensor is deduced, and the influencing factors of powder packing density are analyzed. The finite element method is used to establish the simulation model of the sensor. Based on the simulation software COMSOLMultiphysics, the output performance of the sensor is simulated and analyzed. The sensor has a shielding cover, a radial electrode, an electrode plate angle and a shield radius. The influence of the depth of the radial electrode embedding, the thickness of the electrode plate and the position of the helical shaft blade on the output performance of the sensor is investigated. The structural parameters of the sensor are selected, which provides a theoretical basis for the development of the sensor. Then, based on MS3110 chip, the weak capacitance detection circuit of powder stacking density capacitive sensor is designed. A powder stacking density detection system based on MSP430F149 single chip microcomputer is built. The software of the testing system is designed, and the whole test system is debugged. The absolute error of weak capacitance detection is 卤0.0018 PF, and the relative error is 卤0.36. Finally, using the dried wheat flour as the screw feeding powder, a calibration device for powder packing density detection is designed, and the calibration test, output performance test and testing performance test of powder packing density sensor are carried out. The results showed that the nonlinear error between the output capacitance and the packing density of the capacitive sensor was 卤2.388, the detection sensitivity was 3.131, the absolute error of the output capacitance was 卤0.0173 PF, the relative error was 卤0.66. The absolute error between the detection value and the actual value is 卤0.0188 g / cm ~ 3, and the relative error is 卤3.11%.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212

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