带有内外组合桨的搅拌设备内流场的数值研究  

Numerical Investigation of Flow Fields in Stirred Vessel with Combined Inner and Outer Agitators

作　　者：孙会[1] 潘家祯[1] 崔宁[1] 孔令超[1] 杨燕勤[1] 

机构地区：[1]华东理工大学机械与动力工程学院,上海200237

出　　处：《高校化学工程学报》2005年第3期315-319,共5页Journal of Chemical Engineering of Chinese Universities

摘　　要：利用滑移网格法计算了以一定转速比反向旋转的内外组合桨搅拌的搅拌设备内的流场,工作介质分别选取98%甘油和1.5%(wt)CMC水溶液。通过对单桨与内外组合桨产生的流场进行对比,研究了搅拌设备内不同高度处速度、速度变化率、表观粘度及剪切速率的分布特点。结果表明:采用内外组合桨,介质为中粘牛顿流体时,在罐内主体区远离罐壁区域径向速度受到一定削弱,但在某些局部区域被增强,而对于假塑性流体径向速度总体上得到增强。采用内外组合桨可以加强轴向循环,改善搅拌设备近壁区的流动状况,且对假塑性流体流动状况的改善要优于中粘牛顿流体,另外还可以显著地提高搅拌设备内的剪切速率,同时使剪切速率的分布比较均匀。Sliding grid method was used to simulate the flow fields in vessel stirred by combined inner and outer agitators, which were rotating in opposite direction. The test fluids used were 98% glycerin and 1.5% (wt) CMC (carboxymethyl cellulose) aqueous solution, respectively. Compared with single agitator, the velocity, rates of velocity change, the distribution of apparent viscosity, and shear rates at different height were analyzed. Results show that, using the combined inner and outer agitators the radial velocity at the region far from the vessel wall is weakened to a certain degree for the Newtonian fluid with medial viscosity, but strengthened in some local area. In general, the radial velocity of the pseudoplastic fluid is strengthened. The combined inner and outer agitators can increase the axial circulation and improve the flow fields near the vessel wall. The improvement of the flow fields for the pseudoplastic fluid is better than that for the medial viscosity Newtonian fluid. The combined agitators can enhance the shear rates significantly, and cause the distribution of the shear rates to be uniform.

关 键 词：内外组合桨 搅拌设备 数值研究 中粘牛顿流体 假塑性流体 

分 类 号：O357.1[理学—流体力学] TQ027.2[理学—力学]