液相沉淀反应在管式微通道反应器中的流动行为研究  

Research on flow behavior of liquid-phase precipitation reaction in the tubular microchannel reactor

作　　者：姚翰林 辛忠 YAO Hanlin;XIN Zhong(Shanghai Key Laboratory of Multiphase Materials Chemical Engineering,School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China;State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学化工学院,上海市多相结构材料化学工程重点实验室,上海200237 [2]华东理工大学化学工程联合国家重点实验室,上海200237

出　　处：《化工学报》2022年第8期3518-3528,共11页CIESC Journal

基　　金：“超限制造”上海市市级科技重大专项(Y100-2-20075);上海市领军人才项目(2013)。

摘　　要：以碳酸钙水相合成为模型反应,借助对流动反应过程的放大观测,从沉淀悬浮液的流变特性分析了液相沉淀反应在毫米级管式微通道中的流动行为特征以及通道堵塞的过程机理。结果表明,碳酸钙-水悬浮体系的黏度在低剪切速率下随固含率的增加而飙升,而反应通道堵塞的本质可归因于在壁面和流动主体区形成了固含率较高的局部高黏区,使流动性严重恶化。提高反应的流速加快了壁面沉积层和沉淀颗粒团聚体的形成,反而加快了堵塞;其中团聚体的形成远快于沉积层的积累,使团聚体的“架桥”虽晚于沉积层出现,却成为管路堵塞的主要因素。基于破坏流动壁面和主体的局部高黏区,设计了两种新型的微通道反应器模型,有可能为解决反应通道堵塞这一难题提供新的思路。With the aqueous-phase synthesis of calcium carbonate(CaCO_(3)_(3)) as the model reaction and based on the magnifying observation of flow-reaction process,the flow behavior characteristics of liquid-phase precipitation reaction in the milli-scale tubular microchannel and the mechanism of channel clogging were analyzed from the rheological properties of the suspension.The results showed that the viscosity of CaCO_(3)-water suspension increased sharply with the increase of solid content at low shear rate and the nature of clogging could be attributed to the formation of local high viscosity area with high solid content on the wall and in the bulk flow,which made the fluidity seriously deteriorate.Increasing the flow rate of the reaction accelerated the formation of sedimentary layer and precipitation particle aggregates,thus the clogging was accelerated.The formation of aggregates was much faster than the accumulation of sedimentary layer,making“bridging”of aggregates the main factor of channel clogging.Based on the local high-viscosity region that destroys the flow wall and main body,two new microchannel reactor models are designed,which may provide new ideas for solving the problem of clogging of the reaction channel.

关 键 词：沉淀 反应器 流动 堵塞机理 黏度 流变学 悬浮系 团聚 

分 类 号：TQ021.1[化学工程]