Research On Ball Mill Modeling Methods Based On Molecular Dynamics

Nowadays the ball mill is widely used in metallurgy industry, chemical industry, electricity and other important industrial fields. Especially in the manufacturing process of the thermal power plant, the ball mill acts as one of the important auxiliary facilities. The steady work of the ball mill can guarantee the safe operation and the economic benefits of the power plant.Firstly, this paper summarizes the theory of ball mill modeling and monitoring. Then, combining the movement of the ball mill and the molecular dynamics method, an internal model of ball mill is built on the software platform of DEM. At last, the running condition of the ball mill can be simulated based on the model. The model in the thesis develops the relationship between the kinetic energy of the moving steel balls, the coal storage and the efficiency of the ball mill. This paper describes three typical moving states of the steel balls inside during the running of the ball mill, and then the corresponding kinetic models are also built getting the relationship between the kinetic energy and the coal storage. After sketching out the basic theory of molecular dynamics and the operational processes of DEM platform, we decide the ball mill model, steel balls, coals and the physical parameters like the stiffness, density and damping. Then the whole process of the ball mill gets simulated. And the relationship between different coal storage and movement of steel balls under a particular radius are analyzed. Also the real-time regularity between the total power and the energy loss by the friction of the steel balls and the coal is studied.Eventually in the results section, we come to a conclusion that the steel balls can get more impact energy in the thrown down state of motion than the spilled down state of motion. And the kinetic energy of the balls can accurately reflect the real-time changes in coal storage, verifying the feasibility of controlling the coal storage based on the kinetic energy of the balls in the proposed method.