螺带桨搅拌槽内给热系数和所需功率的研究

本文详细研讨了螺带桨搅拌槽内给热系数及其与所需功率的关系.研究中使用了4个不同几何尺寸的螺带装以及8种不同稠度的假塑性非牛顿流体和高粘度牛顿流体.结果表明:在雷诺数小于0.1时,试验流体在槽内的给热系数与浆叶几何尺寸有关.通过回归分析法得到了4个对应于各螺带桨的给热系数关联式;雷诺数大于10时,给热系数和搅拌浆几何尺寸无关,从而得出一个适用于不同螺带浆的共同关联式.实验还研究了给热系数和所需搅拌功率的关系,并用多项式回归法得到了整个实验雷诺数范围的传热-搅拌功率关联式.

Heat Transfer Coefficient and Power Requirement in Helical Ribbon Mixers

This paper deals with an experimental study on the rate of heat transfer in helical ribbon mixers and its relation with power requirement. Four ribbon impellers and eight test fluids of different consistencies and ranging from pseudoplastic non-Newtonian to highly viscous Newtonian were used in the experiment. It was found that heat transfer coefficient is a function of impeller geometry at Reynolds number less than about 0.1.Accordingly there are four correlations corresponding to the four ribbon impellers. At Reynolds number higher than 10, Heat transfer coefficient is independent of impeller geometry and a single correlation is therefore obtaind for all the four impellers. Since both the heat transfer coefficient and power consumption are functions of Reynolds number, a relation is presented between them.