A Numeral Analysis On The Torque Of The Vertical Kneading Mixer’s Blades

Mixing process is one of the key processes for the production of composite materials.The torque which the rotor blade can bear in mixing process is one of the important indexes inthe design of the kneading mixer. The torque not only can simultaneously reflectthe uniform degree of polymer, but also is one of the important parameters in the enlargeddesign from the small-capacity vertical kneading mixer to the large-capacity one. In view ofthe fact that the blades’ torque value is not easy to be measured directly, the blades of thevertical kneading mixer are designed by empirical formulas. Therefore, research on thechange law of the torque in mixing process has an important role in blade’s profile parameters,mixing process parameters and the design of transmission system of the kneading mixer. Inthe paper, based on the vertical kneading mixer’s blades as the research object, numericalanalysis and simulation is introduced on the blades’ torque in mixing process by the FLUENTsoftware, and main conclusions are drawn as follows:Firstly, the physical properties of composite materials in mixing process are analysised.Based on mixing process and blades’ structure of the vertical kneading mixer, solid-liquidtwo-phase fluid of composite materials in mixing process is simplified as single-phase fluid ofpseudoplastic non-Newtonian fluid, and the fundamental governing equations of single-phaselaminar flow model are deduced.Secondly, fluid simulation model in mixing domain is established. The flow field ofcomposite materials is divided into unstructured tetrahedral meshes by the ICEMsoftware. The kneading surface and the top and bottom sections of blades are simplified,based on blades’ structure and simulation calculation requirements. Blade profile is cut intodifferent thick slices. UDF program that can describe the motion relationship with blades inthe mixing tank is compiled by VC, so that the flow domain’s simulation under the action ofblades can be realized. The results show that there is a positive correlation between slices’torque and slices’ thickness, and that slices’ torque is linearly proportional to slices’thickness. Hereby, the torques of the hollow blade, the solid blade and the planetary gear trainare calculated, and are compared with the simulation values of the whole blade with torque errors in a acceptable level.Thirdly, the geometric model of the three-blades of the vertical kneading mixer is built.With the torques of the three blades in larger geometric size in mixing process are researched,through the above simulation method and conclusions, to provide references for the design ofthe larger geometric blade.