Numerical investigation and estimating correlation of micromixing performance of coaxial mixers

In view of the significance, complexity and difficulty of micromixing in viscous system, coaxial mixers with wide adaptability to viscosity are first combined with the micromixing. The effects of feeding position, rotation mode and impeller type on the micromixing performance of coaxial mixers are investigated numerically with standard engulfment model and eddy dissipation concept model (EDC), and a dimensionless estimating correlation of segregation index Xs is established based on the Buckingham π theorem. The results show that feeding near the discharge zone of the impeller favors the micromixing and Rushton turbine impeller (RT) is better qualified as the impeller near feeding point compared with six-straight-blade turbine impeller (SBT) and six-pitched(45o)-blade turbine impeller (PBT). At the same specific power consumption, the coaxial mixer has better micromixing performance with PBT+RT as inner impeller than with SBT+RT, and the difference of segregation index resulting from the rotation mode is ...