Gas-surface interfacial and gas-phase resistances to vaporizing cesium hydroxide and chloride in air

The Effect of Menisci on Kinetic Analysis of Evaporation for Molten Alkali Metal Salts (CsNO3, CsCl, LiCl, and NaCl) in Small Cylindrical Containers

“…This result means that the presence of the foreign gas (air and Ar) would be a dominant parameter in determining the evaporation rate of alkali metal species. As the reported analysis on the mass transfer resistance of evaporation into atmosphere [20], the condensation coefficient of evaporation is the overall mass transfer resistance consisting of the atmospheric gas and the Knudsen layer, but the resistance values of the Knudsen layer are a hundred times lower than that of the atmospheric gas. It means that the contribution of the Knudsen layer to the values of the condensation coefficient is negligibly small even though the Knudsen layer is formed above the fully developed meniscus.…”

“…/ is the evaporated molecular moles per unit of time, is the cross-sectional area of the container, is molar mass, and is the universal gas constant. The condensation coefficient used in the equation is effective for empirically correcting the predicted rate of evaporation into vacuum [16,18,19] or a gas atmosphere [1,[20][21][22][23]. However, determination of the coefficient values in numerous experimental studies on the evaporation process has produced inconsistency.…”