运动颗粒图象分析系统的研究

STUDY ON IMAGE ANALYSIS SYSTEM FOR MOVING PARTICLES

本文描述了能直观记录快速流化床中粒子形态所发展的一种图象分析系统。该系统由外径为6mm 的光导纤维传感器。能产生二次曝光并以微秒级水平进行调节的脉冲氙灯;摄象单元和具有图象处理软件的微型计算机组成。图象传感器的分辨率大于50μm,而图象偏差小于2%,图象放大倍数为70等。这一系统的发展,将提供一种新的直观的非取佯测量技术,为今后对深入研究流化床内各种流动状态下颗粒物料的形态、粒径分布和空隙率等参数提供了一种新的测试技术。

The present paper describes an image analyzing system we developed for visually recording the morphology of particles in fast fluidized beds.The system consists of an optical fiber image sensor 6 mm in diameter,a xenon pulsing lamp which can produce dual exposure and is time-adjustable at a microsecond level,a video unit and a microcomputer with related image processing softwares.The re- solution of the image sensor is larger than 50 micrometer and the image deviation is less than 2%.The optical enlargement is 70 folds. The control circuit of the xenon pulsing lamp,which is adjustable in single exposure time and in time interval of the dual exposure and is able to monitor and display exposure time,can ensure flash- ing synchronously with the video camera and the microcomputer.Thus,the information about particle velocity under different flow conditions can be obtained in a single photo image through dual exposure. The main functions of the digitized image processing software involve image geometric process- ing,grey and histogram processing,image space filter,image computation and image segment,etc. The digitized images can be stored in a 1.2 M diskette and processed at any time desired. This system has been successfully used in the measurement of the morphology of particle clouds of FCC catalyst at various radial positions of a fast fluidized bed 90 mm in diameter and 10 m in height. Large amounts of images obtained have proven the exixtence of particle clusters in the fast fluidized bed and the dependence of cluster size to radial positon of the bed.It is believed that the developmet of this image analyzing system by which the information about particle motion in a micro region inside a fluidized bed can be obtained will provide a new visual non—sampling measuring technique for thor- oughly studying morphology of particulate materials and various parameters such as size distribution and voidage,etc.under different flow conditions in fluidized-bed reactors.