泛能式搅拌桨搅拌特性研究

在直径为 2 4 0mm的搅拌釜内 ,考察了泛能式搅拌桨的功率、传热特性 ,混合实验在直径为 386mm的搅拌釜中进行。在层流域内 ,建立了功率准数Np 与桨几何尺寸及雷诺准数Re的关联式 ;得到了努塞尔准数Nu与桨几何尺寸、雷诺准数Re、普朗特准数Pr以及体系粘度的关系 ,并采用单位质量流体表示的雷诺准数εD4/ν3 取代雷诺准数关联 ,误差均在 10 %以内。在中低粘度区内相同功耗下 ,泛能式桨的传热系数明显高于螺带桨。当Re >3时 ,泛能式桨的混合效率比双螺带桨要高。

Power,Heat Transfer and Mixing Characteristics of Fullzone Agitator

Power consumption and heat transfer efficiency for fullzone agitator were conducted in a diameter 240 mm reactor, and mixing experiment was performed in a diameter 386 mm reactor. In laminar regime, a correlation of the power number with Reynolds number and fullzone agitator geometries was established. It obtained the relationship between Nusselt number with Reynolds number or εD 4/ν 3 , Prandtl number, and the agitator geometries. All errors were less than 10%. Compared with helical ribbon agitator, Nusselt number of fullzone was higher at the same power consumption. When Re * exceeded 3, mixing efficiency of fullzone was better.