Abstract: For measuring size, concentration and velocity of droplets from the cyclone separator's inlet and outlet, a measurement system based on trajectory image processing is developed. Principles of measurement are introduced. Droplets from cyclone separator are always sphere under the surface tension of water. It is reasonable to approximate the width of trajectory particle image as the diameter of droplets. Distance that droplets have moved in exposure time is obtained from trajectory image by processing, velocity of droplets can be easily calculated. Telecentric lens is used as an important part of measurement system. Common lens exhibit varying magnification for objects at different distance from the lens, but Telecentric lens provide the same magnification at all distance, so droplets at different distance are the same size in the image. Firstly, images of particles are taken by capture system, and images are processed with program. Then the particle size, concentration and velocity can be calculated. The system was installed in an experimental set up that was used to study the performance of the cyclone separator. The experiment results show that our system avoids inversed process and with high size resolving compared with traditional measurement system with light scattering method. And it can make a measurement in line，is better than other systems.

Key words: in-line measurement, image processing, cyclone separator, particle size

摘要： 为了对气液旋风分离器进出口液滴粒径、浓度、速度进行测量，研制了一套基于模糊图像测量原理的图像法颗粒粒径、浓度、速度的在线测量系统。具体介绍了测量原理和该系统构成。基于模糊图像处理方法可以得到视场中颗粒粒度与速度信息，结合镜头景深还可以得到流场颗粒浓度。测量系统由图像采集系统、位移控制系统与图像处理系统组成。该系统已被成功安装在某气液旋风分离器实验台上，现场测量结果表明，该系统与光散射颗粒测量方法相比，避免了反演过程，可以得到更高的粒度分辨率，且可以实现实时在线多参数测量，具有较大的优势。

关键词: 在线测量, 图像处理, 旋风分离器, 颗粒粒度