Research On Turning Characteristics Of Pipe Belt Conveyor Based On FEM-DEM

In the production and transportation of bulk materials,the circular pipe belt conveyor is a highly competitive transportation equipment,which has the advantages of closed transportation of materials,flexible line layout,green,intelligent and efficient,long transportation distance and so on.There are many turning sections involved in long-distance circular pipe belt conveying.The conveyor belt in the turning section has large deformation,complex bulk material movement and poor stability of idler under alternating load.Studying the contact force characteristics between conveyor belt and idler and the law of high-speed material conveying can increase the operation stability of the equipment.Firstly,the theoretical calculation of the circular pipe belt conveyor is carried out,including its main parameters,the contact force between the conveyor belt and the idler,the contact force between the material load and the idler,the influence of tension on the conveyor belt and the idler and the turning radius.Secondly,taking the circular pipe conveyor belt and idler in the horizontal turning section as the research object,the rigid flexible coupling model of the circular pipe belt idler group is established,and the explicit dynamic stress analysis is carried out based on the finite element method.ABAQUS software is used to analyze the belt stress and idler contact pressure under the conditions of belt weight,belt forming force,different turning radius,different pipe diameter and different idler group spacing.The analysis shows that under the single factor gravity load,the position stress value of the contact between the conveyor belt and the bottom idler is the largest,and the contact pressure values on the three bottom idler are close.When the conveyor belt is crimped,the belt stress and the contact pressure of the forming device decrease with the increase of pipe diameter.With the increase of turning radius,the contact pressure on No.1-4 idler decreases,and the contact pressure on No.5 and6 idler increases.With the increase of pipe diameter,the transverse stiffness of the conveyor belt increases,the ability to resist deformation increases,and the contact pressure on the idler decreases.With the increase of idler spacing,the contact pressure of idler increases,and the "bending" phenomenon of conveyor belt is more obvious.Then,based on the discrete element method,the motion state of particle flow and the force of conveyor belt in the process of conveying bulk materials are studied.The positive pressure of bulk materials on the five positions of the circular pipe conveyor belt under the conditions of different material filling rate,different belt speed and different turning radius is analyzed by EDEM software.The results show that with the increase of material filling rate,the positive pressure values of A,B,C,D and E on the conveyor belt increase,the maximum value is at point C at the bottom of the belt,and the positive pressure values on the left and right sides of the conveyor belt(points A and E)are about 1/5 of the positive pressure values of point C.The inner speed of the material in the conveyor belt in the horizontal turning section is less than that on the outer side,the fluidity of the particles on the inner side is poor,and the particles "accumulate" on the inner side.With the increase of the speed of the round pipe belt,the speed difference between the particles inside and outside the conveyor belt increases,and the positive pressure value at each point of the conveyor belt is in a state of continuous fluctuation.With the increase of turning radius of circular pipe belt conveyor,the centrifugal force and accumulation of particles decrease.Finally,the simulation shows that the material load has little effect on the contact pressure of the idler.According to the above analysis,this topic can provide a certain reference for the research on the contact characteristics of the turning section of the circular pipe belt conveyor.