ABSTRACT
Roller screen is a key device in pelletizing plants employed to size classification of green pellets. Realistic observations showed that some pellets with size slightly larger than the gap were trapped between the rollers and caused blockage and decreasing the device efficiency consequently. Here, a speed regime for the rollers is proposed and its effects on the device efficiency were studied numerically. To perform the simulations, discrete element method was used and to ensure the results accuracy, surface meshing and the time step sensitivity analysis were performed. Using the numerical results, impact of each of the variables independently and also their cross effects were studied and discussed. The results proved that the proposed gradient speed regime improves the efficiency considerably. However, both the speed regime and the deck angle should be adjusted in optimum values to achieve maximum efficiency.
Acknowledgement
The authors wish to acknowledge the support of Golgohar Mining & Industrial Company. We also thank Golgohar Iron ore and Steel Research Institute (GISRI) and the company pellet factory for their cooperation.
Disclosure statement
No potential conflict of interest was reported by the author(s).