table of contents I. 4-Stage Working Principle of Double Roller GranulatorsII. Core Structural ComponentsIII. Key Features & Primary Applications In modern compound fertilizer production lines and organic fertilizer production lines, cutting energy costs by eliminating post-granulation drying is a major operational priority. A double roller extrusion granulator (also referred to as a dry roll press […]

In modern compound fertilizer production lines and organic fertilizer production lines, cutting energy costs by eliminating post-granulation drying is a major operational priority. A double roller extrusion granulator (also referred to as a dry roll press granulator) uses the powerful compression forces generated by two counter-rotating rollers to directly shape powdered raw materials into dense granules without requiring added water, steam, or liquid binders.

As a professional fertilizer equipment manufacturer and compound fertilizer equipment manufacturer, Taian Hongxin Environmental Protection Equipment Co., Ltd. supplies advanced fertilizer granulating equipment and organic fertilizer granulators as part of our complete fertilizer processing machinery solutions globally.

I. 4-Stage Working Principle of Double Roller Granulators

1. Controlled Material Feeding: Dry powdered raw materials (e.g., organic fertilizer powder, urea, MAP, potassium chloride) are fed uniformly into the roller nip via a screw feeder.

2. High-Pressure Roll Extrusion: Driven by hydraulic or heavy-duty spring pressure, two rollers rotate in opposite directions, compressing loose powder into dense flakes or sheets.

3. Crushing & Precision Screening: The compacted flakes fall into a crusher unit for breaking, followed by a vibrating screen to classify granules into target size ranges (typically 2–10 mm).

4. Closed-Loop Recycling: Reaches a high granulation efficiency of over 90%; any undersized fines or oversized fragments automatically return to the hopper for re-extrusion.

II. Core Structural Components

• High-Wear-Resistant Roller Assembly: Forged from wear-resistant alloy steel or tungsten carbide. Roller surfaces feature customizable pockets (e.g., oval, spherical, square).

• Forced Feeding Mechanism: Comprises a hopper and screw auger to ensure smooth, continuous material delivery without bridge formation.

• Heavy-Duty Drive Unit: Electric motor and hard-tooth gear reducer provide uniform, high-torque counter-rotation.

• Crushing & Screening Unit: Integrated flake crusher and sizing screen ensure consistent particle size distribution.

• Frame & Gap Adjustment Device: Sturdy welded steel frame with an adjustable roller clearance system to regulate sheet thickness and granule hardness.

III. Key Features & Primary Applications

Key Advantages:

• No Binders or Drying Required: Eliminates drying and cooling equipment, reducing energy consumption by 30% to 60%.

• High Granulation Rate & Density: Achieves >90% granulation efficiency with superior crush strength, preventing caking during transport.

• Wide Material Compatibility: Handles powders with 5%–20% moisture content, with low wear-and-tear maintenance requirements.

Primary Application Fields:

• Fertilizer Manufacturing: NPK compound fertilizer production lines, commercial organic fertilizers, bio-organic powders, ammonium sulfate, and trace element granules.

• Chemical & Mining Processing: De-icing agents, inorganic salts, graphite, cat litter, feed additives, and mineral dust briquetting.