Research On Wear Characteristics And Wear Resistance Optimization Of Middle Trough Under Variable Factors

During the transportation of the scraper conveyor,the scraper chain circulates the animal material to move along the chute,which makes the middle trough very easy to wear and fail,and then causes the operation failure of the scraper conveyor,causing huge economic losses.Therefore,it is very important to improve the wear resistance of the middle trough.However,under variable factors(a variety of coal quality factors and various transportation conditions),the wear area and wear degree of the middle trough are very different.Only considering the wear of the middle trough under a single mine condition cannot meet the needs of different mines.Therefore,this article is based on the discrete element method,through the simulation of the operation process of the scraper conveyor,the wear characteristics of the middle trough under variable factors are studied,and the wear-resistant bionic middle trough that meets the specific working conditions is designed and formulated,which is of great significance to improve the service life of middle trough.The main research contents and results of this paper are as follows:(1)The two-way coupling model of DEM-MBD scraper conveyor was established,and the wear characteristics of the middle trough under variable factors were studied.The results show that: under variable factor conditions,the wear area and wear degree of the middle plate in the middle trough are different;For the working conditions of different particle size distributions,when there are more small size coal particles,the three body wear of bulk coal and chain(scraper)at the lower end of the chain leads to the wear area of the middle plate mainly at the lower end of the chain,and the wear degree is larger;With the increase of large particles,the wear of the middle plate gradually moves to both sides of the chain,and the wear is relatively light;For different transportation conditions,the degree of wear of the middle plate from large to small is as follows: uphill 10°,stable,inclined 2° along the advancing direction,and downhill 10°.Because the component of gravity slows down the acceleration process of particles,coal particles are more likely to form accumulations under uphill conditions,and are more likely to get stuck at the lower end of the scraper chain,causing the most serious wear of the middle plate.In addition,except for the uphill condition,the wear degree of the three middle plates in the other working conditions from large to small is: the material output end middle plate,the intermediate middle plate,and the material input end middle plate.(2)The two-way coupling simulation model of the DEM-MBD abrasive wear reciprocating test machine was established,and the wear depth was taken as the response value.Based on the Plackett-Burman screening method and the response surface method,the wear resistance of the four bionic structures was explored.The results show that the anti-friction effect of the pit type and the trough type is more significant;the optimal parameter combination of the pit type under the test conditions is: round pit,diameter 0.9 mm,depth 1.8 mm,angle90°,transverse spacing 13.6 mm and longitudinal spacing 10 mm,of which diameter,depth and transverse spacing are significant influencing factors;The optimal combination of wear resistance parameters of trough type is: shape triangular trough,width 0.54 mm,depth 0.5 mm,angle 46° and spacing 8 mm,of which width,depth and angle are significant influencing factors;The anti-friction effect of the cross trough bionic structure is not significant,but it can reduce the vibration of the scraper chain to a certain extent,so that the force of the middle plate is more uniform;The cross-prismatic bionic structure can provide a reference for the wear-resistant surfacing repair technology of the middle trough.(3)Based on the combination of wear-resistant bionic structure parameters obtained in the above research,a bionic middle trough suitable for specific working conditions is designed,and the wear resistance and wear resistance mechanism of the bionic middle trough are explored through the simulation model of the scraper conveyor.The results show that: the pit type bionic middle plate can reduce the wear of the middle plate twice,and the wear is more uniform;Analyzing the wear-resistant mechanism of pit and trough bionic structure,it is found that the pit and trough structure can not only effectively reduce the contact area between bulk coal and middle plate,destroy the continuity of the surface contact between bulk coal and middle plate,reduce the wear stroke,but also alleviate the stress concentration,at the same time,produce air film between middle plate and coal particles,and reduce the friction coefficient.The wear characteristics of the middle trough under the variable factors studied in this paper and the bionic middle trough designed to meet the specific working conditions can provide new ideas for improving the service life of the middle trough and provide a reference for the design of the bionic middle trough.