Macroscopic estimation method of the mixedness of Kenics type static mixer

We investigated the mixing process of the Kenics type static mixer, in which the mixing is enhanced by both advective mixing and mixing due to molecular diffusion in order to propose an estimation method of the mixedness. The results show that the element divides, folds and stretches the mixing fluids and forms a lamellar structure with striation width l_a. The value of l_a decreases with an increase in the number of elements by l_a-(2^n-1)^-1, which represents the characteristics length of advective mixing. The characteristic length of mixing due to molecular diffusion l_d can be estimated by solving the one-dimensional unsteady species conservation equation analytically. The macroscopic estimation and prediction method of mixedness is proposed as function of l_a and l_d. When l_a>l_d, the advective mixing is dominant, while, when l_a<_d, the mixing due to molecular diffusion plays an important role.