偏心搅拌槽内高浓度浆液颗粒的悬浮特性  

Particle suspension performance of high concentration solution in eccentric stirred tank

作　　者：杨敏官[1] 冯浪[1] 高波[1] 来永斌[1] 

机构地区：[1]江苏大学能源与动力工程学院,江苏镇江212013

出　　处：《江苏大学学报（自然科学版）》2012年第6期643-648,共6页Journal of Jiangsu University：Natural Science Edition

基　　金：国家自然科学基金资助项目(50776040);江苏高校优势学科建设工程项目

摘　　要：以直径为0.34 m的无挡板平底圆筒形搅拌槽为研究对象,对偏心搅拌槽内高浓度浆液中颗粒的悬浮特性进行了数值研究,分析了45°的4斜叶开启涡轮式搅拌桨(PBT)和3窄叶整体板式螺旋桨(ZHX)2种桨型在不同偏心率和转速时,搅拌槽内的流型分布、颗粒体积分数分布、完全离底临界悬浮转速以及功率消耗,并与试验结果进行了对比.结果表明:对于高浓度浆液,偏心搅拌打破了中心搅拌时流场结构的对称性,提高了流体的轴向循环能力,颗粒悬浮效果优于中心搅拌;固体颗粒的悬浮效果与搅拌桨在槽内的偏心位置有关,当偏心率E=0.4时颗粒悬浮效果最佳,但偏心搅拌会增大颗粒的完全离底临界悬浮转速和设备的功率消耗,不利于节能降耗.The particle suspension performance of high concentration solution in eccentric stirred tank was numerically investigated for an unbaffled flat-bottom cylindrical vessel with diameter of 0.34 m.Flow pattern variation,particle volume fraction distribution,just-suspended speed and power consumption were analyzed for two different axial flow impellers,a 45°pitched blade turbine（PBT） impeller and a ZHX propeller at different eccentricities and rotational speeds.The numerical results were compared with experimental data.The results show that eccentric agitation can break up the flow field symmetry of co-axial agitation to enhance the axial flow velocity with particle suspension performance of eccentric impeller better than that of center agitation.The effect of solid suspension depends on eccentricity with optimum eccentricity of 0.4.Eccentric agitation can increase just-suspended speed and power consumption,which is not good for energy saving and consumption reducing.

关 键 词：搅拌槽 偏心搅拌 临界悬浮转速 悬浮特性 功率消耗 

分 类 号：TQ027.3[化学工程]