Double roller press granulators are efficient, energy-saving fertilizer granulation equipment suitable for shaping various materials like organic fertilizer and compound fertilizer. However, not all materials are suitable for direct extrusion granulation. Materials that don’t meet the requirements can lead to low granulation rates, loose granules, or accelerated equipment wear.
1.Material Particle Size
Moderate Fineness: Material that’s too coarse (>2mm) makes granulation difficult, while overly fine material (<80 mesh) can affect flowability. The best particle size range is ideally between 80 to 200 mesh.
Uniform Mixing: Different material components must be fully crushed and mixed evenly to prevent uneven granulation due to particle size differences.
2.Moisture Content Control
Too high moisture (>30%) causes material to stick to the rollers, leading to blockages. Too low moisture (<8%) makes it hard to press into shape.
Optimal Moisture Range: Organic fertilizer: 20%-25%; Compound fertilizer: 10%-15%.
3.Material Stickiness and Plasticity
Materials need some stickiness. Binders like humic acid, bentonite, or lignin can improve particle cohesion, making the granules denser.
4.Material Temperature Effects
Temperatures that are too high (>80°C) can soften the material, affecting the extrusion. Temperatures that are too low (like frozen material) can reduce plasticity.
Recommended Pre-treatment: Some materials (like livestock manure) need to be composted and cooled down before granulation.
5.No Hard Impurities
Hard objects like metal or stones must be kept out of the double roller press granulator. They can scratch the roller surfaces, affecting granulation quality.
In summary, double roller press granulators have strict requirements for material particle size, moisture, stickiness, temperature, and purity. Only materials meeting these standards will ensure high granulation rates, low energy consumption, and long equipment life.