刮膜式分子蒸馏器液体停留时间分布及壁面结构优化Residence Time Distribution of Liquid in the Wiped Film Molecular Distillator and the Wall Structure Optimization of the Wiped Film Molecular Distillator
姚文瑾,李阳,许松林
摘要(Abstract):
在刮膜式分子蒸馏器中,可以通过液体的停留时间分布反映物料蒸发分离特性,研究其规律对改进蒸馏器内的流场结构、优化操作参数和装置的设计都具有重要意义。今采用计算流体力学的方法,建立三维CFD模型,研究了进料速率和转子转速对停留时间分布规律的影响,并且与实验值进行对比验证;对蒸馏器壁面进行了优化,包括水平圆环、倾斜圆环和网状圆环三种优化壁面,并且对其分别进行模拟计算和实验验证。模拟结果显示出与实验结果相同的规律。结果表明,在研究范围内,停留时间随着进料速率的增大而减小;随着转子转速的增大,停留时间先增大,达到一定转速后,停留时间反而减小。经过壁面优化以后,在相同的进料速率和转子转速下,水平圆环壁面和网状圆环壁面的停留时间得到延长,倾斜圆环壁面的停留时间适当缩短;壁面湍动程度增大,有利于传质传热,提高了分离效率。
关键词(KeyWords): 刮膜式分子蒸馏;停留时间分布;计算流体力学;壁面优化
基金项目(Foundation): 国家自然科学基金(20976118,21176170)
作者(Author): 姚文瑾,李阳,许松林
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