基于图像光散射颗粒粒度测量方法研究

研究了基于图像的光散射颗粒粒度测量系统。结合图像处理技术,提出一种最小二乘原理圆拟合光环定中方法,设计CCD探测器光环尺寸与颗粒粒级划分数目。搭建了颗粒光散射图像测量硬件系统,利用非独立模式差分进化算法反演出颗粒粒度。通过8种聚苯乙烯乳胶球标准颗粒实验对测量系统准确性进行验证,测量误差在3%之内;对2种不同体积分数的大豆蛋白乳液进行了测量,与图像粒度仪对比偏差在5%之内。实验结果表明:采用最小二乘原理圆拟合方法定中提取到的散射光能与理论分布更加吻合,35环的光环划分方式有利于获得相对良态特性的光能系数矩阵,该测量方法为颗粒粒度测量提供了一种光散射法有效改进方式。

Research on Measurement Method of Particle Size Based on Image Light Scattering

An image-based light scattering method was investigated for particle size characterization, in which a novel technique of detector ring center determination was proposed using the least-square algorithm combined with image processing technology. The design of the size parameters of CCD sensor and the number of particle size bin were employed. The differential evolution algorithm of dependent mode was also developed for the inversion of particle size distribution. Afterwards, with the established experimental apparatus for image acquisition of scattered light by particles, eight types of polystyrene latex particles were successively tested the accuracy verification, which yielded measurement errors less than 3% after a comparison with the known nominal sizes. What′s more, experiments on two kinds of soy protein emulsion with different oil volume fractions were conducted, and a deviation within 5% from the image analyzer was depicted accordingly. It manifests that the scattered light flux extracted by the least-square centering technology can provide a great consistence with the theoretical predictions. Furthermore, the proposed CCD sensor with ring of 35 rings is quite helpful in leading to a relatively stable sensitivity matrix of light flux. The proposed method presents an effective way to improve the light scattering method for particle size measurement.