【FAQ】How do you handle die clogging in a ring die pelleting machine?

Ring die granulator are widely used for organic fertilizer granulation, but "die clogging" is the most common operational issue—where material compacts and blocks the die holes, causing output to stop, current to spike, and the main motor to trip due to overload. Quickly and correctly resolving this issue is crucial for resuming production. Troubleshooting causes of clogging: Excessive material moisture content (>20%): Moisture seeps out during extrusion, forming a paste that adheres to the inner walls of the die holes, eventually hardening and causing a blockage. Raw materials contain overly long fibers or insufficiently ground coarse particles (length >10mm): These get stuck in the die holes and cannot be extruded. Late-stage die wear: The inner walls of the die holes become rough, increasing frictional resistance and making it difficult to push the material through. Excessive feed rate: The feed rate exceeds the pellet mill's extrusion capacity, causing material to accumulate and compact within the die chamber. Emergency handling steps: Immediate shutdown: If a significant drop in output or a continuous rise in current is detected, stop feeding and cut power to the main motor immediately. Do not force the machine to run, as this could burn out the motor or damage the ring die. Clear the die holes: Open the pellet mill's access door and use a specialized punch rod or high-pressure air gun to clear the blocked holes one by one. For mild blockages, injecting vegetable oil or a mold release agent into the holes and letting them soak for 5–10 minutes makes clearing them easier. For severe blockages (hardened material), remove the ring die and heat it in an oven to 80–100°C to soften the hardened organic matter before clearing it with a punch rod. Restart: After clearing the blockage, start the main motor without a load. Once it is running smoothly, gradually increase the feed rate. It is recommended to feed a small amount of oily material (such as rapeseed cake powder) before resuming normal feeding to "lubricate the die" and reduce initial frictional resistance. Preventive Measures: Enhance material screening prior to granulation by using a fertilizer screening machine to remove oversized fibrous material and metallic impurities. Strictly control the moisture content of the input material; use a drum fertilizer dryer to pre-dry the material to the optimal granulation range of 12%–16%. Maintain a usage log for ring dies to track the cumulative tonnage processed by each set, scheduling refurbishment or replacement when output drops to 70% of the initial level. Equip the system with a variable-frequency feeder interlocked with the main unit's current; the feeder automatically reduces the feed rate when the current reaches 90% of the rated value to prevent overloading and die clogging.