Straw Pellets Turning Black Core Causes & Solutions
Core Issue: Excessive carbonization of raw materials due to high temperature and pressure in the pelletizing chamber
Excessively High Temperature
Causes: Slow feeding speed, high ring die rotation speed → prolonged material retention time, intense friction
Solutions: Increase feeding speed; reduce ring die rotation speed; activate cooling device
Abnormal Moisture Content
Causes: Too high (>18%) → carbonization due to steam stewing; too low (<10%) → heat generation from increased friction
Solutions: Control moisture content within the range of 12%-15%; dry if over-humid, humidify properly if under-humid
Equipment Malfunctions
Causes: Too small gap between ring die and press roller (<0.1mm); worn parts
Solutions: Adjust the gap to 0.1-0.3mm; replace worn components
Raw Material/Blockage Problems
Causes: Sand and gravel impurities in raw materials; blocked ring die holes leading to material accumulation
Solutions: Screen out impurities; regularly clear blocked ring die holes