RESS法制备微细颗粒的喷嘴内流动特性的数值模拟  

Numerical Simulation of Flow Characteristics in the Nozzle During Preparation of Fine Particles With RESS Process

作　　者：刘永兵[1] 易健民[1] 赵媛媛[1] 

机构地区：[1]湖南理工学院化学化工学院,湖南岳阳414000

出　　处：《当代化工》2010年第3期319-322,共4页Contemporary Chemical Industry

基　　金：湖南省自然科学基金资助项目(07JJ3016);湖南省教育厅科研资助项目(06C368)

摘　　要：为了对RESS法制备微细颗粒过程中喷嘴内流体规律进行研究,通过对超临界流体快速膨胀法(rapid expansion of supercritical solution,RESS)流动过程的研究与分析,建立了喷嘴内超临界流体流动数学模型。对喷嘴内流场和温度场进行研究,考察了预膨胀压力、预膨胀温度、长径比等操作参数对RESS过程的影响,模拟结果表明,喷嘴内部的密度曲线在喷嘴入口段,几乎没有发生变化,而在直管段和出口膨胀段超临界流体密度发生急剧下降;随着长径比的增大,喷嘴内密度曲线变陡;随着长径比的增大,喷嘴出口处流体的温度都变小,过饱和度变大,结晶颗粒使得更为细小。该模型和模拟过程能够为实现制备均一微细颗粒的实际操作条件和优化过程参数奠定基础。To study on flow characteristics in the nozzle during preparation of fine particles,according to the study and analysis of the rapid expansion of a supercritical solution process,a flow model of the nozzle during preparation of fine particles was established,and the flow field and temperature field in the nozzle were studied.The effects of the pre-ex-pansion pressure,pre-expansion temperature,aspect ratio and other operating parameters on the RESS process were in-vestigated.The calculated results showed that the nozzle density curve was almost unchanged at the entrance section,while in the straight pipe section and export expansion section the density curve dramatic declined,with increase of the aspect ratio,the nozzle density curve steepened;with increase of the diameter ratio,the nozzle exit fluid temperatures were smaller,over-saturation bigger,made more small crystalline particles.The model and simulation process could lay a basis for preparation of uniform fine particles in the actual operating conditions and optimizing the process parameters basis.

关 键 词：超临界流体快速膨胀法 喷嘴 流动模型 微细颗粒 

分 类 号：TQ021.3[化学工程]