Granulation is the core process in NPK compound fertilizer production, directly determining the appearance, strength, and effectiveness of fertilizer granules. A wide variety of compound fertilizer granulation equipment is available on the market, suitable for large, medium, and small production scales. The mainstream equipment is mainly divided into three categories: disc granulators, rotary drum granulators, and double roller press granulators, each with unique technological advantages and applicable scenarios.

Disc granulators are commonly used in small and medium-sized compound fertilizer production lines, employing a wet granulation process. The equipment uses an adjustable-angle rotating disc, combined with water mist or steam spray, to agglomerate and bind the raw materials into granules. This equipment has a simple structure, is easy to operate, and has low debugging difficulty; a single person can operate it. The granulation rate can reach over 93%, producing round, uniform granules with excellent appearance and low return material. Its capacity is moderate, with an hourly output of 0.5-5 tons, suitable for small fertilizer plants with an annual output of 10,000-30,000 tons. Its disadvantage is that it is difficult to adapt to large-scale industrial continuous production.
The rotary drum granulator is a core piece of equipment in large-scale compound fertilizer production and is also the most widely used granulation equipment. It also employs a wet granulation process, relying on the continuous rotation of the drum, combined with steam humidification and heating, to cause the material to continuously tumble, compress, and agglomerate within the drum. This equipment boasts high capacity, stable operation, and strong formula adaptability, meeting the needs of large-scale continuous production of high, medium, and low concentration compound fertilizers. It also features a built-in scar removal function and a low failure rate. Its drawback is that the hardness of the finished granules is relatively low, and the granule appearance is slightly less uniform compared to other equipment.
The double-roller press granulator is a dry granulation equipment that requires no water or steam and can directly form granules at room temperature. It compresses dry powder raw materials into granules through high-pressure extrusion, followed by crushing and screening to obtain the finished granules. No drying process is required, resulting in low energy consumption and no waste emissions. The granules produced by this equipment have high strength and are not easily pulverized. It is suitable for non-sticky raw materials such as urea and potassium chloride, as well as heat-sensitive bio-compound fertilizers. It has low investment costs, quick returns, and is suitable for small to medium-sized energy-saving production lines.
In summary, each of the three types of granulation equipment has its own advantages. Enterprises can flexibly select the appropriate type and match it with supporting equipment according to their production scale, fertilizer formula, and capacity requirements to ensure efficient and high-quality compound fertilizer production.