煤粉粒径分布在气固两相流场中的测试技术研究

针对输送管道内煤粉颗粒的粒径分布宽的特点，用侧向接收散射光的Mie散射方法和Fraunhofer衍射方法作了理论分析和实际测试。利用分子筛和显微镜对被测粒子进行了静态测量，其结果可以作为相对准确的测量标准。研究结果表明，针对细粉分离器内煤粉颗粒的形状、浓度和粒径的分布规律，用衍射测试方法可以达到较高的测试精度，取得较好的测试效果。

Size Distribution Measurement of Coal Particles in Two-Phase Flows

It is necessary for coal particles manufactured by powder-generator to have a suitable size and amount as well as less power consumption. In case of the wide size span of the coal particles ducted, Mie scattering and Fraunhofer diffraction theories are used to measure the distribution of the coal particles in lab. With semi-conductor laser and ellipsoidal reflector, the scattering light is received from the direction perpendicular to the incidence light in Mie scattering measurement. The relative accurate standard is obtained by using the molecule screen and microscope. The particles are absorbed by the vacuum pump and pass through the laser-lighted area. The relative standard coal particles obtained by the molecule screen can obtain the matrix of probability which implies the relationship between the number of particles related to scattering light signals and sizes. Based on the standard, these two methods are verified by experiments. Experimental results show that these two methods are feasible and the Fraunhofer diffraction is more effective.