面向最优固含率的推进式搅拌器固相悬浮性能研究  

Research on suspension performance of propellers for optimum solid concentration applications

作　　者：杨潮 王博 张自强 肖清 刘宝庆[1] YANG Chao;WANG Bo;ZHANG Zi-qiang;XIAO Qing;LIU Bao-qing(Institute of Process Equipment,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学化工机械研究所,浙江杭州310027

出　　处：《高校化学工程学报》2021年第3期415-422,共8页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(21776246,21978255)。

摘　　要：稠密固-液搅拌操作中,优化固含率可以有效降低能耗、减少污染。在较宽固含率范围内,实验研究了推进式搅拌器的固相悬浮性能,考察了搅拌桨直径、桨叶离底高度等结构参数和固相粒径、液相黏度等物性对临界离底悬浮状态下单位质量功率的影响。结果表明,随固含率增加,单位质量搅拌功率先减小后增大,存在最优固含率,具有最低单位质量搅拌功率。对比不同工况,桨叶离底高度的变化对最优固含率的影响较小;而桨叶直径和固相粒径的增大,均会使最优固含率减小。黏性体系与清水体系相比,单位质量搅拌功率更小,最优固含率更高。此外,建立了推进式搅拌器驱动下单位质量搅拌功率的预测公式,可用来确定不同工况下的最优固含率,从而为工业上固-液搅拌操作中选择合适的悬浮液操作浓度提供一定的指导。Optimization of solid volume fractions can effectively reduce energy consumption and pollution in dense solid-liquid mixing.Effects of propeller diameter,impeller off-bottom clearance,particle size and liquid viscosity on power consumption(per unit mass)were investigated under a wide range of solid loading.The results show that as the solid volume fraction increases,the stirring power per unit mass decreases first and then increases,and there exists an optimum solid concentration with the lowest stirring power consumption.The impeller off-bottom clearance have little effect on the optimum solid concentration under different working conditions.In addition,the increase of blade diameter and particle size decrease the optimum solid concentration.Viscous system had a lower power per unit mass and higher optimum solid concentration compared to that of water system.This study can help to predict optimum solid concentrations under different working conditions by numerical simulation of power per unit mass for just off-bottom solid suspension conditions,and provide guidance for the the selection of appropriate suspension concentrations in industrial solid-liquid mixing operations.

关 键 词：固-液搅拌 黏性体系 推进式搅拌器 最优固含率 

分 类 号：TQ465.92[化学工程—制药化工]