Numerical Simulation of a Single and Double-Rotor Impact Crusher Using Discrete Element Method

The Discrete element method (DEM) is an invaluable tool for studying comminution as it provides detailed information that can help with process analysis as well as trying out new equipment designs before the equipment is physically built. The DEM was used to analyse previous experimental work to gain some insight into the comminution process in an impact crusher with a single impeller. Further DEM simulations were done on a crusher with a second impeller installed. The energy spectra and threshold energy levels calculated from the drop-weight test were used as the basis of comparison. The simulations indicate that even at much lower speeds, the performance of a double impeller impact crusher is exceedingly superior. However, the energy associated with the double impeller impact crusher is much higher and energy intensification, rather than energy efficiency, is the main gain of the double impeller design. The double impeller also offers more operational flexibility, such as spacing between the impellers, which can be tailored to the particle size range being handled.