剪切搅拌器关键结构参数的优化设计

Optimization Design of Key Structural Parameters of Shear Agitator

为研究剪切搅拌器关键结构参数对搅拌效果的影响,对剪切搅拌器优化前后的内流场进行数值计算。以搅拌功率、流速为判定依据,分析了圆盘外圆直径D_(1)、半球形叶片直径R对搅拌效果的影响。研究结果表明:D_(1)在320~360 mm范围变化,R不变的情况下,增加D_(1)使搅拌器轴功率增加,当D_(1)=360 mm,R=85 mm时,搅拌器功率为26.5 k W;R在75~95 mm范围变化,D_(1)不变的情况下,增加R也可使搅拌器轴功率增加,当D_(1)=330 mm,R=95 mm时,搅拌器功率为28.3 k W;改变D_(1)轴功率变化率约为0.08,改变R轴功率变化率约为0.41,改变D_(1)速度平均改变量约为0.02 m/s,改变R速度平均改变量约为0.065 m/s,表明D_(1)和R在相同增比的情况下,改变R使搅拌器获得更大的轴功率和流体剪切速率。

For purpose of investigating the influence of shear stirrer’s key structural parameters on the stirring effect,the internal flowfield before and after optimizing the shear stirrer was calculated by numerical calculation method.Based on the determination of stirring power and flow rate,the outer diameter’s(D_(1))influence of the disc and that of hemispherical blade’s diameter(R)on the stirring effect were analyzed.The results show that,when D_(1)changes in the range of 320 mm to 360 mm and R keeps unchanged,the agitator shaft’s power is increased;when D_(1)equals to 360 mm and R equals to 85 mm,the stirrer power is 26.5 kW;when R ranges from 75 mm to 95 mm and D_(1)keeps unchanged,increasing R can also increase the agitator shaft power;when D_(1)equals to 330 mm and R equals to 95 mm,the stirrer power stays at 28.3 kW;when the change rate of D_(1)axis’power is about 0.08,the change rate of R axis power is about 0.41,the D_(1)’s average speed change is about 0.02 m/s,and the R’s average speed change is about 0.065 m/s,which indicates that,when D_(1)and R have the same increase ratio,changing R can give the agitator greater shaft power and fluid shear rate.