Research On Vibration Impact And Structure Optimization Of Transfer Point Of Belt Conveyor

In the coal production system of the coal preparation plant,the reasonable design of the transfer chute of the belt conveyor is one of the main means to improve the economic benefits of the coal preparation plant.Therefore,the impact analysis of the material flow at the transfer point and the structural optimization of the transfer chute are of great significance to the production and transportation of the coal preparation plant.This paper takes the belt conveyor transfer system as the research object,aiming to solve the problems of the current transfer system,such as the high lump coal crushing mass ratio and the excessive vibration impact on the belt conveyor below.The main tasks are as follows: experimental research on the material flow characteristics at the transfer point,dynamic analysis of the blanking process at the transfer point,and determination of the theoretical idea of structural optimization The optimization design of chute structure and the simulation comparison analysis before and after the structure optimization.According to the field investigation and relevant literature review,the following research work is mainly carried out in this paper:(1)In view of the problem that the impact of different material flows at the transfer point on the belt conveyor is not clear at present,the optical fiber vibration detection system was used in this paper.The material flows with different particle sizes and different water contents were used to impact the belt conveyor.During the impact process,the vibration of the belt conveyor below the transfer point was detected,and the detection results were analyzed in detail.First,build a vibration detection system in Labview software.Then,collect the vibration waveform of the belt conveyor at the transfer site in real time on site,and compare the vibration characteristics under different conditions to analyze the impact of different material flows on the belt conveyor.(2)In view of the high lump coal crushing rate at the transfer point and the low service life of the main parts caused by the current static structure design of the chute,this paper conducts a theoretical analysis of the dynamic impact process of the material flow on the belt conveyor based on the research method of combining theoretical research and simulation analysis.According to the momentum theorem,the material flow is equivalent to the accumulated mass of lump coal in a certain period of time,and considering the equivalent impact force generated by the coal inflow speed,the influencing factors of the combined impact force of the material on the lower belt conveyor are obtained: the accumulated mass in the falling process,the feeding speed,and the blanking height.The related factors are analyzed in the simulation software LS-DYNA,and the theoretical idea of chute structure optimization is obtained.(3)In view of the problems such as blockage of coal blocks passing through the chute,insufficient space for the construction of the on-site chute,high lump coal crushing rate,and fatigue damage caused by excessive impact of the conveyor belt at the transfer point,the transfer chute structure was improved by combining theoretical analysis with the idea of approximately reducing the blanking height.The structure of the blanking port was changed to a straight cylinder type,and a two-stage buffer plate was added inside to alleviate the impact force of the material flow during the transfer process.Then in the EDEM simulation software,the equivalent impact force of coal on the belt conveyor before and after the structure optimization and the speed change of coal particles in the blanking process are analyzed to determine the rationality of the structure optimization.(4)Aiming at the problem that the lump coal crushing particle process established by EDEM simulation is relatively complex,and the lump coal model with large aspect ratio,sharp edge,included angle and other characteristics cannot be simulated,this paper introduces the whole process of lump coal crushing analysis at the transfer point of belt conveyor in Rocky simulation software in detail,not only analyzes the lump coal crushing process of the existing transfer chute structure The crushing ratio under different blanking heights is compared,and the crushing mass ratio before and after the structure optimization is analyzed in detail,which verifies the correctness of the chute structure optimization.