关键词: 在线测量, 图像处理, 旋风分离器, 颗粒粒度

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