搅拌槽中垂直列管外壁的传热膜系数分布

在一内径为 12 0 0mm容积为 1.5m3 的搅拌槽中 ,使用CBY螺旋桨、 4 5°斜叶桨和六直叶涡轮桨 ,对牛顿流体采用量热法 ,研究了列管外壁的局部传热膜系数的分布情况。实验结果表明 ,对轴向流桨和径向流桨 ,列管外壁的局部传热膜系数有不同的分布 ;列管外壁各点的局部传热膜系数均与ε0 .197成正比。此外 ,文中还研究了桨叶离底距离、桨径等因素对列管外壁局部传热膜系数的影响。

The Distribution of Heat Transfer Film Coefficient of Vertical Tubes in a Stirred Tank

In a stirred tank which was 1.2m in diameter and 1.5m 3 in volume with ellipsoidal bottom, by using a calorimetric method, the local heat transfer film coefficients on the outer surface of the vertical tubes used as baffles were measured with three types of impellers including CBY propeller, PBT and Rushton turbine. The difference of axial distribution of the heat transfer film coefficient between the CBY propeller and Rushton turbine was considerable. The effects of clearance of impeller, diameter of impeller and power consumption on the local heat transfer film coefficient were studied.