Abstract: Two rotor continuous mixer is a kind of continuous mixing device with excellent dissipation and distribution properties. In this paper, the chaotic mixing characteristic of twin-rotor continuous mixer has been analyzed, and a modified Lyapunov index based on the residence time of material, which can be used to describe the tensile strain in the process of mixing, has been put forward. In addition, by finite element analysis, the modified Lyapunov indexes of most flow field region, computed by Polyflow software, are all more than zero. Vortical flow of stretch and fold can be found in the mixing flow field, which is very favorable for mixing and endows the two rotor continuous mixer with excellent dissipation and distribution mixing abilities.

Key words: Two rotor continuous mixer, Chaotic mixing