【摘要】 采用孔内当地传质系数(舍伍德数)表征IPA在竖直孔内的蒸发速率,对不同孔口水平气流速度和孔径条件下,竖直孔中IPA液体的当地传质系数变化情况进行了实验研究.结果表明:随着IPA液面远离孔口,IPA蒸发时存在强对流传质、对流传质和自然扩散3个阶段;气流速度越大,孔内径越大,IPA孔内当地传质系数越大;相同气流速度下,小孔(3 mm≤d≤5 mm)中的当地传质系数比微孔(0.05 mm≤d≤0.20 mm)中的当地传质系数大100倍.按照孔径范围,分别开发了适用于小孔和微孔中IPA当地传质系数关联式.更多还原

【Abstract】 The evaporation rate of IPA under three kinds of flow velocities and six kinds of hole diameters were experimentally studied,and the local mass transfer coefficients(Sherwood number) inside holes that indicate evaporation rate were analyzed.The experimental results show that IPA evaporation process can be divided into three different steps: strong convection,convection mass transfer and diffusion.The local mass transfer coefficient is larger under condition of higher flow velocity and larger diameter of hole.The local mass transfer coefficients inside holes whose diameters ranging from 3 mm to 5 mm are about 100 times larger than those inside holes whose diameters ranging from 0.05 mm to 0.2 mm.Two correlations of local mass transfer coefficient were developed for mm-scale holes and μm-scale holes respectively.更多还原