2026/03/09
The core reason disc granulators are classified as wet granulation is that their pellet formation relies on a liquid binder. The forming mechanism and supporting processes are consistent with wet granulation characteristics, distinguishing it from dry extrusion molding.
During operation, powdered material enters an inclined rotating disc. Water or a special binder is sprayed through atomization, creating liquid bridges on the powder surface. Under centrifugal force and friction, the powder rolls and agglomerates, gradually forming pellets like a snowball. The entire process relies heavily on the liquid phase, and the material's moisture content is typically controlled between 20% and 35%, which is crucial for pellet formation. Without liquid, the powder cannot adhere and agglomerate, making pellet formation impossible.
Pelletized pellets from disc granulation have high moisture content and low strength, requiring subsequent equipment such as a biology organic fertilizer dryer and cooler to remove excess moisture and increase pellet hardness, ultimately meeting storage, transportation, and usage requirements. This is the typical process of wet granulation. Dry granulation, on the other hand, relies on high-pressure extrusion for direct forming, requiring no large amount of liquid phase and no drying process.
Meanwhile, the process control of disc granulation revolves around moisture content, spray volume, rotation speed, and tilt angle, making it suitable for the production of viscous materials and slow-release fertilizers, organic fertilizers, and compound fertilizers. The finished granules are round and uniform with a high yield. Considering the pelletizing principle, material state, and supporting processes, the disc granulator clearly belongs to the wet granulation process and is also the most widely used wet pelletizing equipment in the industry.
