存在液膜的毛细蒸发过程研究

Investigation on the capillary evaporation process based on the existence of liquid film

采用水浴恒温蒸发方法研究了液膜存在时的毛细蒸发过程.研究结果表明:毛细蒸发过程中液/气界面符合黏性指延,且不受蒸发速度及液膜状态的影响;蒸发过程可分为剧烈减速、匀速蒸发、线性减速蒸发和边界效应四个阶段,分别对应不同的液膜状态;毛细蒸发的主要区域在毛细管端口液膜处,工质由液体区流向端口蒸发区的过程中液膜起到了通道桥梁作用.

The capillary evaporation process with stable liquid film along the cell wall is investigated by evaporating under constant temper- ature. The experimental results show that the liquid/vapor interface coincides with viscous finger, which is independent of the state of liquid film and evaporating rate. During the evaporation process, four stages are found： sharp falling rate stage, constant rate stage, linear falling rate stage and boundary effect stage, which are corresponding to different kinds of liquid film states. The evaporating takes place mainly at the tip of the liquid film region, and the stable liquid film transports the liquid from the liquid region to the capillary tube orifice.