The Stimulation Of Maize Crushing By Hammer Mill And The Test Of Hammer Performance Based On Discrete Element Method

Hammer crusher has been widely used because of its simple structure,simple operation and high production efficiency.As a key component of crushing materials,hammer has a direct impact on the performance of crusher.The improvement of the hammer structure can improve its comminution performance.For this reason,this paper takes the CPS-420 hammer sheet mill as the experimental prototype,and designs two new hammer sheets(blade hammer sheets and bevelled hammer sheets)on the basis of comprehensive analysis of domestic and foreign related research and theoretical analysis.With the aid of the discrete element simulation technology,the process of corn comminution is simulated,and the influence of the end shape of hammer on the material flight path and comminution process is studied.On the basis of the above research,the comminution performance of two kinds of new hammers was tested.The research contents and achievements of this paper are as follows:1.Based on relevant research and theoretical analysis at home and abroad,two new types of hammer are designed.The size,installation method and end shape of the new type hammer disc were designed with the CPS-420 hammer disc mill as the test platform.2.In this paper,the static friction coefficient,density and water content of maize seeds were measured experimentally.The parameters of static friction coefficient,ultimate compression force and ultimate shear force were calibrated,and the calibration error was within 10%.3.The discrete element model which can be used to simulate the comminution process is established,and the comminution process is simulated by the discrete element analysis software edem.The simulation results show that the oblique hammer can significantly reduce the incident angle,reduce the speed of materials,and facilitate the timely screening of materials.The split blade hammer can break more bonding keys and improve the impact on materials.4.Taking corn(Xianyu 355)as the grinding object,the comminution performance of open-edge hammer,oblique hammer and common hammer were tested.The test results show that the chipping efficiency can be improved by using the open-edge hammer,and the energy consumption can be reduced by using the slanted hammer.When the linear velocity at the end of the hammer piece is 70m/s,compared with the ordinary hammer piece,the power consumption index of the inclined hammer piece is reduced by 14.07%on a ton of material,but the production efficiency is reduced.Compared with ordinary hammers,the productivity of working hours is increased by about 5%.5.The discrete element simulation and performance test show that the grinding performance can be improved by using the cutting edge and the bevel opening of the hammer.The bevel opening of the hammer can change the flight path of the material,reduce the material speed,facilitate the screen,and the installation of the bevel opening can reduce the material consumption of tons;Hammer blade cutting treatment can break more bond,improve the productivity of mill hours.This study can provide a method basis for the design of a new type of hammer crusher,and also provide a reference for the discrete element crushing simulation of other materials.