NPK fertilizer granulators are core equipment in the production of nitrogen, phosphorus, and potassium compound fertilizers. Different granulation processes correspond to different models, adapting to different production scales, raw material characteristics, and product requirements. Currently, there are four main models in the industry, each with its own advantages and disadvantages, covering all scenarios from small workshops to large-scale production lines. They precisely solve the core need of "converting powdered raw materials into granules," helping to improve fertilizer quality and production efficiency.

The rotary drum granulator is the most widely used wet granulation machine, suitable for small and medium-sized fertilizer plants. Its core principle is to use the rotation of an inclined drum, through centrifugal force and gravity, to make the moist NPK raw material tumble and agglomerate inside the drum, gradually forming uniform granules. This model has a simple process, low equipment investment, and can flexibly adapt to various NPK formulas, allowing the addition of trace elements. Its disadvantages are the need for a drying system, slightly higher energy consumption, and moderate granule strength. It is suitable for cost-sensitive enterprises with moderate output.
The extrusion granulator is a dry granulation machine, requiring no drying and consuming even less energy. It feeds pre-treated dry powder raw materials into the granulation chamber via a feeding system, and uses pressure rollers to extrude the material under high pressure (10-30 MPa), shaping it through a mold groove. The resulting granules are then shaped and polished. Its advantages include high forming rate (over 90%), dense granules, and no need for binders, meeting the needs of green agriculture. Its disadvantages include strict requirements for raw material particle size and moisture content, making it suitable for small to medium-sized production lines, especially for dry powder granulation.
The disc granulator is a traditional small-scale granulation equipment with a simple structure and convenient operation. Through the rotation of an inclined disc, NPK raw materials are subjected to centrifugal force and friction within the disc, agglomerating into granules with the help of a suitable wetting agent. This model has a small footprint and low investment, suitable for small-batch production, and allows for flexible adjustment of particle size. However, its output is lower, and particle uniformity is poorer, making it suitable for small workshops or experimental production.
Each of the three models has its own suitable application scenarios. The rotary drum granulator balances cost and adaptability, making it the mainstream choice for small and medium-sized manufacturers; the extrusion granulator focuses on energy conservation and environmental protection, and is suitable for the granulation needs of dry powder raw materials; the disc granulator is suitable for small-batch production or trial use. When choosing a model, it is necessary to consider the production scale, raw material characteristics, and product positioning to maximize efficiency while ensuring granule quality, thus providing high-quality NPK granular fertilizer for agricultural production.