Discrete Element Simulation And Application Of Coal Silo Unloading

It is difficult to define the flow pattern during the unloading process of coal silos,and the problems of stratified and mixed unloading are complicated,and the ash is difficult to predict.This paper explores the unloading law of silos from the two aspects of silo test and discrete element silo simulation,and obtains the influence law of coal material moisture content,coal particle cohesive energy density on coal silo unloading process,and the law of coal material mixed stratification discharge.Through software development,a coal unloading process simulation system for the clean coal 2# warehouse of the GuoBei Coal Preparation Plant is established,realizing the real-time monitoring of the coal silo quality information and the ash forecasting function.Firstly,through experiments,the law of stratification and unloading of materials in coal silos is explored.With the increase of unloading volume,the proportion of mixing in different coal seams is increasing,and the trend of mixing proportion is close to linear.The total amount of hybrids from the beginning of mixed discharge to the end of mixed discharge is about 55%.Within a certain range of moisture content,as the moisture content increases,the degree of mixing of different coal seams in the coal silo will gradually decrease,and the material flow in the silo will be closer to the overall flow state.In addition,in the process of discharging the material in the silo,if the material particles are subjected to other external forces,it will greatly affect the discharge flow state of the material in the warehouse,thereby affecting the degree of mixing of the layered discharge.Secondly,through discrete element simulation,the order of unloading from different coal seams is explored,and the unloading rules of different coal seams and related factors affecting the discharge law are explored.For the stratified mixing in the unloading process,as the amount of material increases,the total degree of mixing will gradually decrease,and the degree of mixing will be calculated from the starting point of the mixed discharge,and the amount of unloading will not cause the change of the degree of mixing.In addition,the influence of interparticle cohesive force on delaminated hybrid discharge is explored.It is found that the cohesive energy density between particles had no direct influence on the mixed discharge of different coal seams.A set of coal unloading process simulation system was developed,real-time collection and storage of warehouse quality information was realized,and the integration process of warehouse and ash data and the establishment of coal seam 3D model were completed,and the forecast of ash output was realized.Through the application of the software system,real-time monitoring of the quality information of the warehouse inventory and the ash prediction of the warehouse can be realized.The simulation system predicts that the average deviation of ash and actual shipping ash is 0.154,which effectively improves the efficiency of clean coal product transportation management.