关键词: Maxwell-Stefan方程, 多组分质量传递, 外场强化传质

Abstract: Fick’s law of diffusion is only valid for the description of an ideal binary diffusion without external force, while Maxwell-Stefan (MS) equation can be applied to multicomponent mass transfer under the influence of external field. The physical meaning of MS equation was clearly explained, and the generalized expression of MS equation was rewritten to a form which is simpler and easier for use. The expressions of the external forces which could be used in the equation were given. Fick’s law of diffusion is the special form of MS equation to the mass diffusion in ideal binary fluid without external force. The application results of MS equation to the centrifugal separation and the electrolyte diffusion are consistent with that of traditional descriptions, but more comprehensive. In this paper, application of MS equation to electric conduction leading to Ohm’s law was carried out, which provides a new method to get diffusivity through the measurement of conductivity. The characteristic of mass transfer in spherical particles enhanced by electric field was investigated with MS equation, and this investigation showed that MS equation could effectively describe the mass transfer enhanced by external field. MS equation provides an effective theoretical method to study the mass transfer enhanced by external fields.

Key words: Maxwell-Stefan equation, multicomponent mass transfer, mass transfer enhanced by external field