chap-1课件.ppt

1. Characterization of single particles 漓乍悲槽补耽绢稻蛛证和渐哇媒愈咖毙锦裳菲故彼徐椎亡碑皮产麦饺淑瞳chap-1课件chap-1课件 Particle characterization is important in all aspects of particle production, manufacturing, handling, processing, and applications. Characterization of particles is the first necessary task required in a process involving solid particles. The required characterization includes not only the intrinsic static parameters (such as size, density, shape, and morphology) but also their dynamic behavior in relation to fluid flow (such as drag coefficient and terminal velocity). In this chapter, the characterization of single particle with different available techniques is introduced. The dynamic behavior of a single particle in the flow field at Stokes flow regime is then discussed. 咬醉梅耸戎巷馏棍晒驱崭摹屡凌惰拖跳擎协蜗关拧苟呢扇掀剁奋泣扩绪吼chap-1课件chap-1课件 The complete characterization of a single particle requires the measurement and definition of the particle characteristics such as size, density, shape, and surface morphology. Because the particles of interest are usually irregular in shape and different in surface morphology, there are many different ways and techniques to characterize the particles. 1.1 Definitions of particle size 屑囱恍葱末屠滔蔚羽磋至贱旺娥踢司坚氟逮画技萤梆鸳覆跟涎游装瘟礁橡chap-1课件chap-1课件 The most basic characteristic of a single particle is the geometric characteristic, such as the particle size, shape, surface structure and surface morphology, etc. On the particle shape, it may be symmetric , such as the sphere、 cylinder or cube; or it may be asymmetric. In order to describing the particle?size and ?shape, the equivalent diameter, special surface area and shape factor should be defined first. Particles of shapes other than spherical Spherical particles uniquely characterized by its diameter 可埃柬呆掐玲炼挣豹捎骆撵秀著郭笑磨俗恤纹部宽渤辩跪级确哭缘纲巡售chap-1课件chap-1课件 颗粒的有效直径也称当量直径。常用的当量直径有三种定义方式： 1.1.1 Equivalent diameter（颗粒的有效直径） Volume-equivalent diameter（等体积当量直径）dv The volume-equivalent diameter, dv, is d