化工学报2013，Vol.64Issue(7)：2418-2427,10.DOI:10.3969/j.issn.0438-1157.2013.07.016
单进口后混式射流粉碎中多相流混合机理及加速特性
Mixing mechanism of multiphase flow and acceleration performance in single inlet rear-mixed jet flow crushing
摘要
Abstract
In order to deeply understand the super fine crushing technology of rear-mixed high-speed water jet flow,the mixing and jetting behavior of gas-liquid-solid three phases in acceleration tube with various diameter were investigated by using numerical simulation and crushing experiment methods.Mixing mechanism and acceleration performance of multiphase mixture jet flow were explored,and particles distributions in acceleration space were obtained.The result showed that aeration and entrainment effects of jet flow turbulent motion were the inherent mechanism of mixed attached phase.There existed many partition zones in the rear-mixed jet flow for particle acceleration.Whereby the nearer to the potential flow zone,the stronger the impact energy.Accordingly,optimizing configuration of the optional nozzle diameter with the acceleration tube diameter could force the particles near or enter the potential flow zone,whereby effectively improving grinding yield efficiency.The particles in space distribution within the acceleration tube were in the highest contents in high-efficiency acceleration zones of the outer and inner layers.As a result,the nearer to the potential flow zone,the fewer the particles.The particle contents in the air flow zone increased with increasing acceleration tube diameter.It was difficult for the particles to enter the ideal acceleration zone so that most of the particles were accelerated by relying on the highefficiency acceleration zone of the inner and outer layers.In the case of maintaining the flowing morphological state of free jet flow,the grinding yield efficiency decreased with increasing acceleration tube diameter.Accordingly small tube diameter was of better constraint and concentration functions for water jet flow energy and particle motion space.关键词
多相射流/混合机理/加速特性/射流粉碎Key words
multiphase jet/ mixing mechanism/ acceleration characteristics/ jet flow crushing分类
矿业与冶金引用本文复制引用
万继伟,牛争鸣,廖伟丽,牛助农..单进口后混式射流粉碎中多相流混合机理及加速特性[J].化工学报,2013,64(7):2418-2427,10.基金项目
国家自然科学基金项目(51179152) （51179152）
陕西省重点学科建设专项资金项目(00X902) （00X902）
supported by the National Natural Science Foundation of China (51179152) and the Important Academic Special Construct Foundation of Shaanxi Province (00X901). （51179152）
