摘要
以底部椭圆形封头十字形挡板搅拌反应釜为研究对象,采用Fluent软件分析搅拌桨流型、离底高度、直径、底部加装挡板及其高度和长度对该搅拌釜内流场的影响,利用标准k-ε湍流模型对其在单相流体水中产生的流场进行模拟。开展搅拌轴转矩的试验研究,并与模拟值进行对比。研究表明,径向流搅拌桨更适合于底部加装挡板搅拌釜流场的研究。与六直叶圆盘涡轮搅拌桨相比,六直叶开启涡轮搅拌桨更有利于反应釜内物料的悬浮及混合。搅拌桨离底高度取0.7倍液面高比0.6倍更合适。搅拌桨直径越大,轴向速度越大,反应釜中心部位形成的螺旋向上轴向流越明显。在十字形挡板高度或长度固定时,搅拌桨下部区域中心部位的轴向速度比其他部位大,搅拌釜内上桨、下桨叶区将形成一个循环。同等条件下,随着搅拌转速不断增大,搅拌轴转矩随之增大。搅拌轴转矩的模拟值与试验值的相对误差在10%左右,两者具有很好的一致性。
The effect of flow pattern,impeller diameter,the height above the bottom,cruciform baffles,the height and the length of the cruciform baffle on flow field are numerical analyzed in the elliptic header stirred tank with cruciform baffles using the software Fluent.The turbulence model of k-ε is employed to simulate the flow filed of water.The experiment of agitator shaft torque is investigated,and it is compared with numerical value.The results show that the radial flow impeller is more suitable for flow field research on the elliptic header stirred tank with cruciform baffles.Compared to six straight blade disc turbine stirring paddle,six straight blade on turbine stirring paddle is more advantageous to mixing and suspension of material.The height above the bottom as 0.7 times of liquid level is more suitable than 0.6 times.When the impeller diameter is much bigger,the axial velocity is more fast,the logarithmic spiral upward axial flow in the central of the stirred tank is more and more obviously.If the height or the length of the cruciform baffle on the flow field is constant,the axial velocity in the center of stirred tank bottom will more larger than other parts,and a loop will be formed in the stirred tank.The torque turn to larger as the rotary speed increasing under the same conditions.The relative error of agitator shaft torque is about 10 ％ between simulation value and experimental value.Both of simulation value and experimental value of agitator shaft torque have a good consistency.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2014年第6期156-164,共9页
Journal of Mechanical Engineering
基金
国家重点基础研究发展计划(973计划
2012CB723902)
国家高技术研究发展计划(863计划
2012AA040208)资助项目
关键词
十字形挡板
椭圆底封头
搅拌釜流场
转矩
cruciform baffles
elliptical header
stirred tank flow field
torque
作者简介
王星星（通信作者）,男,1984年出生,博士.主要研究方向为机械搅拌设备设计、特种加工、先进焊接技术及自动化.E-mail：paperwxx@126.com
