摘要
不同搅拌工况下剪切性能的需求是选用搅拌器的一个重要指标,文中基于对常规的6种搅拌器流场的CFD模拟,计算了搅拌器各自的剪切性能量纲一数C_3,分析了搅拌流场中剪应力的累计概率分布及统计平均结果。二者对比发现:从宏观平均效果上看,搅拌器剪切性能满足直叶桨>斜叶桨,圆盘涡轮>开启涡轮>桨式;而剪应力极大值影响作用则是直叶圆盘涡轮>斜叶圆盘涡轮>直叶桨式>斜叶开启涡轮>直叶开启涡轮>斜叶桨式。因此,对剪切作用敏感的搅拌过程,在采用常规的搅拌器剪切性能评价的基础上,还需要充分考虑搅拌流场中剪应力极大值的影响,合理选用搅拌器。
Based on the CFD simulation of the conventional six kinds of agitator flow field, the dimensionless number C3 of the shear performance of the agitator is calculated, the cumulative probability distribution and statistical average results of shear stress in stirred flow field are analyzed. The result showed that, from the macro average effect point of view, mixer shear performance meet the straight blade paddle 〉 paddle blade, disc turbine 〉 open turbine 〉 paddle; and the effect of the maximum value of the shear stress is the straight disc turbine 〉 oblique disk turbine 〉 straight blade paddle 〉 oblique open turbine 〉 straight open turbine 〉 oblique blade paddle. Therefore, as to the mixing process which is sensitive to the shear effect, on the basis of the evaluation of shear performance of conventional agitator, it is necessary to take the influence of the maximum value of shear stress into account in choosing agitators rationally.
出处
《化学工程》
CAS
CSCD
北大核心
2017年第8期68-73,共6页
Chemical Engineering(China)
基金
国家自然科学基金资助项目(11102153)
陕西省自然科学基础研究计划青年人才资助项目(2013JQ2001)
省级大学生创新创业训练计划基金资助项目(S201710697020)
关键词
搅拌
剪切性能
CFD
无量纲数
累积概率分布
agitation
shear property
CFD
dimensionless number
cumulative probability distribution
