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.isopropanol