含有角液膜及盐分结晶的毛细管蒸发  

Solution evaporation in capillary tube with corner liquid film and salt crystallization

作　　者：叶超 陈枫 吴睿 YE Chao;CHEN Feng;WU Rui(School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《中国科技论文》2021年第12期1307-1312,共6页China Sciencepaper

基　　金：国家自然科学基金资助项目(51776122)。

摘　　要：采用微通道可视化流动实验方法,对毛细管内氯化钠溶液蒸发干燥过程进行实验研究。实验发现:不同的晶体成核点会生长出多孔晶体和非多孔晶体这2种不同形式的晶体,且晶体通过生长方向的不同,也会出现不同的生长模式;实验中晶体的生长造成了溶液饱和蒸汽压下降,析出的多孔晶体毛细作用使得溶液向晶体表面流动,使蒸发面积与蒸汽浓度增大,造成了蒸发速率的轻微上升;而晶体在通道内角液膜处的生长会使膜内液体流动阻力增大,造成角液膜的断裂,但随着内部多孔晶体的继续增大,强大的毛细作用使溶液向晶体处流动,使角液膜重新连接,在断裂的角液膜处结晶重新生长。The evaporation and drying process of sodium chloride solution in capillary tube was studied by micro channel visualization flow experiment.It is found that according to the different positions of nucleation points,two different kinds of crystals,porous and nonporous,will be grown,and different growth patterns will appear when the direction of crystal growth is different.In the experiment,the growth of the crystal resulted in the decrease of the saturated vapor pressure of the solution,and the capillary action of the precipitated porous crystal made the solution flow to the crystal surface,which increased the evaporation area and the vapor concentration,resulting in the slight increase of the evaporation rate.However,the salt crystallization at the corner liquid films increased the corner flow resistance,which in turn led to the receding of the corner liquid films.But with the growth of the porous crystal,the liquid from the active porous crystal imbibed into the dead porous crystal,which then became active and grows again.

关 键 词：传质 盐分晶体 可视化实验 毛细蒸发 

分 类 号：TK121[动力工程及工程热物理—工程热物理]