Simulation Of Ultrafine Mixture And Disintegration Based On Discrete Element Method

In the ultrafine grinding filed, stirred mill using stirred rod driving the grinding media; ball milling using the movement of drum to driving the grinding media, are both designed for the larger speed of grinding media; besides, airflow pulverization directly make the broken between particle and particle or particle and wall by even supersonic. In mill, air jet mill and stirred mill based on CFD and ball mill mainly by DEM.Mixing of the material as well as particle crushing in the ultrafine grinding is necessary for ultrafine grinding. In this paper, simulating the ultrafine mill work process by DEM software, include the mixture of different particles. ensure realistic simulation of the stirred mill work process. Moreover, by mechanics, the individual particles of pulverized simulation study. Main tasks are as follows:(1) Based on the knowledge of calculation thought of the DEM and relevant development, generally used contact were introduced, mainly based on Hertz-Mindlin contact theory; deeply understand Rayleigh time step and software time step control method, contact parameters.(2) The individual particle of the pulverized simulation. Based on the Hertz-Mindlin bonding contact model. Use of extrusion crushing and impact crushing by crushing single particles with geometric face contact. The results showed that the first broken part and the particles are related to the geometric surface contacts.(3) With stirred mill as example, based on the Hertz-Mindlin (no slip) contact model. Study of mixture of particles and the process of the pulverizing. By different times, different particle size of the mixture effect in the process of crushing. In addition, based on one kind of stirred mill structure performance analysis. Calculated at different speeds, the speeds of distribution of the particles, the important characteristics of the particle velocity weighted value, and the impact energy-impact times.