Rotor Profiles Evolutionary Design and Evaluation of the Mixing Performance for Intermeshing Counter-rotating Twin-screw Kneader

Abstract

In order to solve the expressions of mathematical model, performance optimization and comparison among all kinds of different types of rotor profiles of intermeshing counter-rotating twin-screw kneader, a unified mathematical model for the design of different rotor profiles is established. When changing the teeth number of female and male rotors and other design parameters, a series variety of screw rotor profiles, including those commonly used rotor profiles, can be obtained by evolution method. The visual simulation of dynamic mixing process for a high viscosity non-Newtonian fluid in the flow channel of several typical screw rotors with particle tracer method is implemented. To represent the mixing performance of rotors including distributive and dispersive mixing, contrastive analysis for some parameters, such as residence time distribution density function, separation scale, rate of extension and rate of shear, etc., are carried out. The results show that the distributive mixing ability of differential twin-screw kneaders is better than that of traditional intermeshing counter-rotating twin-screw kneaders, the dispersive mixing ability of traditional intermeshing counter-rotating twin-screw kneaders is superior to which of differential twin-screw kneaders. The results provide a data basis for the selection of rotor profiles and optimization of performance of intermeshing counter-rotating twin-screw kneader.