Research On Wear Mechanism Of Extruder Screw Based On Material Characteristics Of Corn Straw

Straw extruder is an important equipment for comprehensive recycling of crop straw.The screw wear of corn straw during extrusion treatment is serious,which leads to the problems of poor quality of extruded products,low extrusion rate and increased productio n cost.Current research shows that screw wear is related to many factors,such as mater ial properties,structural parameters,operating parameters,material properties and so on.Based on the existing research of the team,through the analysis of the physical an d mechanical properties of straw materials,it is found that the knotted and knotless state of straw has a great impact on its mechanical properties.According to the test of moist ure content and hardness of straw,the fitting curve between moisture content and hardne ss of straw is obtained by programming function with matlab.Firstly,based on the extrusion process of corn straw,the mathematical model of str aw material movement in the barrel of the extruder was established,and the pressure in the spiral cone barrel was deduced,which was related to factors such as spiral angle,sc rew diameter,material density,etc.The speed of material movement was related to facto rs such as spiral angle,screw speed,pitch,etc.Secondly,under different moisture conten t conditions,different mixing ratio had knots/knots.The load state and wear condition of straw on screw surface are different,so the wear mechanism and main wear form of sc rew are determined,the wear prediction model is established,and the main influencing f actors of wear rate are obtained.Using discrete element method and EDEM discrete ele ment simulation software,the load curve of screw surface is obtained,and the space cur ve of water content-surface load-time is obtained.According to the load simulation mode l,the screw wear simulation model is obtained by using Hertz-Mindlin(no slip)model e xtended Archard Wear.Finally,the theoretical analysis and simulation simulator are valid ated by using 1:1 test prototype.The correctness of the calculation.This paper provides a theoretical basis for straw processing and utilization and the design and maintenance of related agricultural machinery and equipment through the stud y of the above problems.