
To fix the powder-only output issue of a biomass pellet mill, control the moisture of wood and straw biomass feedstock at 12%–18% (the root cause) by watering over-dry material or drying over-wet material, grind new dies with an oil-sand mix, clear blocked die holes and replace worn dies.
Set the roller-die clearance to 0.1–0.3mm for slight contact and smooth jam-free rotation, keep crushed feedstock size no more than 1/3 of the die hole diameter, avoid overfeeding, clean residue before restarting, and feed gradually for trial runs.