碰撞诱发颗粒团聚及破碎的力学分析  

Mechanical analysis of agglomeration and fragmentation of particles during collisions

作　　者：张文斌[1] 祁海鹰[1] 由长福[1] 徐旭常[1] 

机构地区：[1]清华大学热能工程系,北京100084

出　　处：《清华大学学报（自然科学版）》2002年第12期1639-1643,共5页Journal of Tsinghua University(Science and Technology)

基　　金：国家重点基础研究专项经费资助项目(G19990222)

摘　　要：有别于以往对颗粒团聚问题宏观而粗略的研究,提出从微观受力的角度探索颗粒团聚及破碎的机理。对循环流化床内运动颗粒的全受力分析表明,一般流化条件下,影响颗粒团聚及破碎最主要的作用力为弹性力和vanderWaals力。通过建立基本的Newton运动学方程并结合材料力学可以推导出碰撞变形过程中弹性力和vanderWaals力随碰撞时间的变化规律;进一步对比两者在碰撞过程中的相对大小可对颗粒团聚和破碎的趋势进行力学解释。The mechanisms controlling agglomeration and fragmentation of particles in a circulation fluidized bed (CFB) were derived from microscopic observation of the processes rather than simplified macroscopic views. The general force analysis on moving particles in CFB shows that, for common fluidization conditions, the dominate forces affecting agglomeration are the impact force and the van der Waals force. The variations of the two forces over time in a collision process were deduced using Newton's fundamental equation and material mechanics. The agglomeration mechanism during collisions was then analyzed mechanically by investigating the relative magnitudes of the two forces during the collision process.

关 键 词：颗粒团聚 力学分析 颗粒碰撞 弹性力 vanderWaals力 循环流化床 颗粒破碎 碰撞变形 

分 类 号：TQ051.13[化学工程] TQ0