Phenomena 1: Only Powder, No Pellets Forming

• Root Cause: Failure in nucleus formation. The fine powder lacks sufficient cohesive force to agglomerate.

Troubleshooting Checklist & Solutions:

• 1. Insufficient Moisture (Most Common)

• Cause: There is not enough liquid to create the necessary capillary force between particles.
• Solution: Grab a sample from the spray zone. It should form a ball when squeezed and feel damp without dripping water. Gradually fine-tune and increase the liquid spray volume.

• 2. Hydrophobic Raw Materials

• Cause: Certain organic materials (such as dry straw powder or sawdust) repel water and are difficult to wet.
• Solution: Add a trace amount of surfactant to the liquid binder, or extend the mixing time after pre-wetting the material.

• 3. Material Coarseness

• Cause: Coarse particles larger than 40-mesh act like dry sand and cannot bond together.
• Solution: Inspect your crusher/pulverizer screens to ensure at least 80% of the raw material passes through a 40-mesh screen.

• 4. Improper Pan Parameters

• Cause: The pan inclination angle is too flat or the rotation speed is too slow, causing materials to slide rather than roll and form a “curtain.”
• Solution: Increase the inclination angle to 45°–55° and simultaneously increase the rotation speed until the material exhibits a distinct parabolic rolling motion.

Phenomena 2: Oversized “Ping-Pong Balls” or Huge Clumps

• Root Cause: Uncontrolled growth and over-agglomeration after the nucleus forms.

Troubleshooting Checklist & Solutions:

• 1. Excessive Moisture or Uneven Spraying

• Cause: Liquid is pouring down like a flood, instantly bonding powder and seeds into massive clumps.
• Solution: Always use atomizing nozzles; completely eliminate solid water streams. Check for clogged or leaking nozzles and ensure an even mist over the material bed.

• 2. Excess Binder

• Cause: The addition of binders like bentonite or starch exceeds 2%, making the mixture too sticky.
• Solution: Strictly control the binder ratio. If needed, blend in a small amount of dry powder to dilute the stickiness.

• 3. Rotation Speed Too Slow

• Cause: Centrifugal force is insufficient to lift larger pellets. They sit at the bottom of the pan, continuously picking up fine powder and growing indefinitely.
• Solution: Increase the disc rotation speed to leverage centrifugal force, forcing larger pellets to the overflow discharge zone.

Phenomena 3: Highly Uneven Pellet Size (Powder, Pellets, and Clumps Coexist)

• Root Cause: Instability in both nucleation and growth stages. This is the most common and complex issue.

Troubleshooting Checklist & Solutions:

• 1. “Pulse-like” Irregular Feeding

• Cause: Fluctuating material flow disrupts the operational balance inside the pan.
• Solution: Utilize a steady-flow feeder. Monitor the main motor’s ammeter to ensure the needle remains stable without drastic spikes.

• 2. Incorrect Spray Zone Positioning

• Cause: Liquid is being sprayed onto already-grown pellets or onto bare pan surfaces.
• Solution: Direct the spray nozzles precisely at the mixture zone of fine powder and initial seeds. This is the golden zone for nucleation.

• 3. Large Scraper Clearance

• Cause: Material build-up on the bottom periodically collapses, suddenly releasing an influx of irregular chunks.
• Solution: Adjust the clearance of the bottom and side scrapers to 1–2 mm to keep the disc surface clean and uniform.

• 4. Mismatched Pan Parameters

• Cause: A poor combination of inclination angle and speed causes chaotic material trajectories.
• Solution: Lock in the inclination angle first (based on material stickiness), then micro-adjust the speed until clear, segregated material zones appear in the pan.

Phenomena 4: Low Pellet Strength (Crumbles Easily Under Pressure)

• Root Cause: Insufficient compaction during the layered growth stage.

Troubleshooting Checklist & Solutions:

• 1. Rolling Path Too Short

• Cause: The material doesn’t roll long enough in the pan, discharging before the “onion-skin” layers are tightly compacted.
• Solution: Slightly decrease the inclination angle or slow down the speed to extend the material’s retention time in the disc.

• 2. Inadequate Liquid Phase

• Cause: Internal moisture is too low to facilitate optimal binding and compaction during rolling.
• Solution: Without causing the material to stick to the pan, slightly increase the liquid spray volume.

• 3. Excessive Fiber Content

• Cause: High fiber content resists compaction, creating weak, “hollow” pellets.
• Solution: Increase the pulverization fineness of the raw materials so that the ultra-fine powder can thoroughly coat and wrap the fibers.

Pro-Tip from the Experts:

When troubleshooting a pan granulator, always adjust the material properties first (moisture, fineness), then optimize the mechanical parameters (angle, speed, scrapers, nozzles). Following this exact order will save you hours of trial and error.

Need More Assistance?

If you are facing specific granulation issues, contact the EMCC Technical Support Team today. Let us know your exact symptoms (all powder, large clumps, or uneven sizing), and our engineers will provide a customized diagnosis for your production line.