Research On The Extrusion Molding Mechanism Of The Embedded Planetary Gear Screw Extrude

Screw extruders occupy a very important position in the food industry,plastic machinery,and feed processing and production industries.Among them,single-screw extruders and twin-screw extruders are the most widely used.After the material enters the extruder,the screw will perform shearing and mixing work at the same time,so the optimization of the screw performance plays a crucial role in the optimization of the overall performance of the extruder.The traditional screw extruder has problems such as insufficient material shearing,poor mixing performance,and low flow channel pressure in extrusion performance,which seriously affects the output of the extruder and product quality.To solve these problems,the researchers improved the shear mixing performance of the screw by adding elements such as reverse threads,meshing blocks,and special mixing blocks.Among them,the reverse thread element has significant advantages in prolonging the residence time of the material and increasing the internal pressure of the flow channel.Based on the concept of reverse thread,this research innovatively embeds the planetary gear element inside the screw,so that the ordinary screw can be decelerated in the reverse direction.Rotation to achieve coaxial speed change,which not only achieves the effect of reverse thread through the reversal of the screw,but also further prolongs the residence time of the material through the deceleration of the screw.The predecessors have carried out in-depth research on the transformation of the screw,but the research on the optimization idea of "coaxial speed change" is relatively shallow.This research takes the most popular single-screw and twin-screw extruder as the research object,and embeds it in its interior.Planetary gear,analyzes the extrusion mechanism,and compares it with the traditional screw,providing a new idea of "coaxial speed change" for the optimization of the screw extruder.In this study,the basic theory of screw is analyzed first,and the principle of screw meshing,the ratio of length to diameter and the size of the barrel gap are investigated,and the preparation for screw design is carried out.Then the three-dimensional modeling of the screw was performed using Solidworks,and the screw flow channel was analyzed using the ANSYS/CFX module.According to the screw size,a planetary gear element composed of a central gear,three planetary gears and an outer ring gear sleeve is designed.Shaft variable screw.Then,the new single screw and traditional single screw are divided into one group,and the new twin screw and traditional twin screw are grouped into one group,and each group adopts the comparative analysis method.Since this study mainly investigates the changes of the shear mixing performance and the pressure building performance of the flow channel after the screw is embedded in the planetary gear,the performance of the new and old screws in the macro pressure field,the velocity vector field,and the velocity streamline field is selected as the The evaluation criteria and the simulation results show that the screw extruder with built-in planetary gear element has a significant improvement in pressure building performance and shear mixing performance compared with the traditional screw extruder.Finally,in order to ensure the reliability of the simulation analysis results,this study sets up corresponding verification tests for the pressure building performance and shear mixing performance of the screw,and uses soybean meal as the test material to verify the simulation results through experiments to ensure "coaxial speed change".This new concept has good promotion and application value.