Analysis of Crushing Performance of Toothed Double-Roll Crusher for Coal Particle Based on Discrete Element Method

The large toothed double-roll crusher, as key crushing equipment for open pit mines, is very necessary to analyse its crushing performance at different feed particle sizes, compressive strengths of coal, and rotation speeds of toothed rollers. Firstly, a toothed double-roll crusher is taken as the research object in this paper; the coupling simulation model of the toothed double-roll crusher based on the DEM-MBD and Ab-T10 breakage model is constructed. The validity of the coupling simulation model is verified through the actual measurement data. On this basis, the crushing performance under variable factors is analysed by integrating comprehensive tests. The results show that the rotation speed of the toothed roller is the main influence factor on the crushing performance of the toothed double-roll crusher when it works at 25~33.3 r/min. With the increase in compressive strength of coal, the productivity decreases, and this phenomenon disappears gradually at 33.3~42 r/min. Further, a 5–20% increase in the large size of the coal particles can improve 10% crushing quality with a discharge size lower than 300 mm and approximately 25% productivity of the toothed double-roll crusher. Finally, the power density is reduced as the mass percentage of large-sized coal particles increases, and this phenomenon is weakened with the increase in the compressive strength of coal.