Performance Analysis And Structure Optimization Of Heterogeneous Surface Breaking-down Shove

Because of the way of loading coal into the train, the coal in the middle of the car will pile up while there will be less coal in the brim of the car, therefore, the coal must be leveled off, that is to push the coal mounded in the middle to the edge space till the top surface of coal is leveled in order to avoid rise and flying of the coal during the transport process and ensure the train's carrying efficiency. At present, most of the breaking-down shoves in use are rectangle with a flat section. However, the efficiency of this kind of breaking-down shove is very low and the leveling quality is poor. The most obvious problem is that an extra artificial leveling is needed to meet the requirement of railway transportation because the coal in the middle and at the back of the car is still piled up due to the coal cannot be pushed to both sides timely. There are a little improvement for some breaking-down shoves:welding acuminate prominent parts in the middle of the rectangular area, which makes it easier to push the coal; although the efficiency of streaming the coal has been improved, the problem is still not solved fundamentally, therefore, to get an ideal effect of leveling coal, the shape of the shove must be improved.Aiming to improve the breading-down shove to push coal to both sides of the car, this paper focuses on the optimizing the shape of shove structure; introduces discrete element method to the leveling coal process and conducts simulation analysis with PFC3D software. The study in this paper includes:1,Based on granular dynamics and contact mechanics in the discrete element method, the movement rules and contact force change of coal granules will be analyzed theoretically to find out the contact model of coal granules in the process of leveling.2,According to the actual parameters of coal in the coal mine, conduct modeling of the loading car with PFC3D discrete software, and analyze the equilibrium state of the model by the software to ensure the optimizing of breaking-down shove structure can be carried out in a balanced discrete element car models.3,Using the wall granules concept of PFC3D software, simulate shove structure by using granules group arrangement, in this way the coordinates of granules can be changed directly to get different shapes of shove structure. This method is not only simple and quick but the simulation effect is very clear as well.4,Through the leveling simulation of 4 kinds of shoves with PFC3D discrete element software, the granule distribution diagram, granule velocity vector diagram and contact force tree diagram can be obtained in different numbers of cycle coal. Comparing and analyzing those diagrams give rise to the trend direction of optimal shove structure.