薄膜蒸发器传热蒸发性能的实验研究

An Experimental Study on the Properties of Heat Transfer and Evaporation of Thin-Film Evaporators

在自行研制的0.4m2薄膜蒸发器实验测试装置基础上,对介质水及烧碱溶液进行了蒸发实验,得到了在不同工艺操作参数下薄膜蒸发器内各料液总传热系数K和蒸发强度EI的变化曲线。实验结果表明,转子转速及进料量对设备总传热系数K及蒸发强度EI影响显著,各料液均存在最佳进料量。粘度增加,总传热系数K相应减少,蒸发强度EI相应增加,实验与数值模拟结果变化规律一致。研究结果表明,从蒸发强度而言,薄膜蒸发器更适合于高粘度料液的蒸发浓缩。

An evaporative experiment was made of the medium water and caustic soda solution based on the self-developed experimental measuring apparatus of 0.4m^2 thin-film evaporators, the variation curves of the overall heat transfer coefficient K and evaporation intensity EI of all feed liquids in the thin-film evaporators under various operating parameters were obtained. The experimental result shows that the rotor velocity and feed rate affected the overall heat transfer coefficient K and evaporation intensity EI of the evaporators greatly, there was an optimum feed rate for each feed liquid. The overall heat transfer coefficient K was proportionally reduced and evaporation intensity EI was proportionally increased when viscosity rose, the variation laws of the experiment result and numerical simulation result were the same. The research result shows that the thin-film evaporators were more suitable to the evaporation and concentration of high viscous liquids for evaporation intensity.