1. The bearing of roller granulator is badly lubricated or even seriously worn.
2. The switch circuit is in poor contact or the single phase is disconnected.
3. Check whether the voltage is too low. If the sound of doule type of pelleting machine is abnormal in the process of operation, the drum will be blocked by obstacles, or even unable to rotate, and the bottom box will vibrate.

This is usually caused by an object in the bottom box, which then causes granular material to fall off and rattle the barrel. In this case, stop maintenance and troubleshooting. There are also some organic fertilizer equipment reducer due to lack of oil or poor oil quality and overheating. Gears and worms are worn out or badly meshed. Poor lubrication or severe wear of bearings. If the strength of the magnetic field of the organic fertilizer equipment becomes weak, the cause of this situation is usually excessive temperature. If the temperature of dry making pellets equipment is too high, the temperature will rise.
The following link can help you to know more information of our machine, please click it.
https://www.fertilizerfactorymachine.com/double-roller-granulator/