Study On The Rotor Structure Optimization And Flow Field Mixing Characteristics Of Internal Mixer

The rotor structure is a major factor affecting the mixing characteristics of the internal mixer. In this paper, a new laminated rotor of internal mixer was designed according to differential principle. And the effects of different helix angles, the ratios of long flight to short flight, speeds of rotor and mixing times on mixing flow field characteristics and mixing effect were studied. The shearing rate, mixing index, the power of disagglomerating and mixing efficiency in mixing flow field were simulated using a finite element package POLYFLOW to evaluate the mixing effect. Preparation of epoxy resin (EP)/multi-walled carbon nanotubes (CNTs) were also conducted using internal mixer to verify the simulation results. Based on the analysis and experiments, the main conclusions are made as follows:(1) The helix angles of the rotor are a major factor affecting the flow field characteristics and mixing effect. When the rotor helix angle is21.7°, the rotor has a good dispersion mixing effect; while the helix angle of the rotor is7.6°, the rotor has a better distributive mixing effect.(2) The ratios of long flight to short flight are also a major factor affecting the flow field characteristics and mixing effect. when the ratio of the long flight to short flight is2:1, the rotor has a good dispersion mixing effect; but when the ratio is1:2or2:1, the rotor have the same distributive mixing effect. The experimental results show that the samples have the highest tensile strength when the ratio of the long flight to short flight is2:1.(3) Rotor speed promotes the dispersion and distributive mixing of the material when the rotor structure of rotor and mixing time is constant. The simulation and experimental results show that EP/CNTs composites have the most excellent mixing effects when the rotational speed of the rotor is600rpm.