The NPK fertilizer granulator serves as the core component of a compound fertilizer production line. To consistently produce compound fertilizer with uniform granules and compliant nutrient content, it must be integrated with a comprehensive suite of auxiliary equipment—covering pre-processing, post-processing, conveying, and dust removal systems—that operate in coordination. Drawing on years of experience in manufacturing fertilizer equipment, Huaqiang Heavy Industry categorizes the necessary auxiliary equipment into three main segments based on the production process: raw material pre-processing, post-granulation processing, and auxiliary conveying/handling systems.

Raw material pre-processing equipment is the foundation for ensuring granulation quality; it primarily includes automatic batching systems, crushers, and mixers. The automatic batching system uses electronic scales to precisely measure raw materials—such as urea, ammonium phosphate, and potash—ensuring strict control over the NPK ratio and minimizing errors associated with manual proportioning. Chain-mill crushers break down caked raw materials to the appropriate fineness, preventing large particles from interfering with the granulation process. Double-shaft paddle mixers thoroughly blend various powdered raw materials, achieving a mixing uniformity of over 95%, thereby preparing the mixture for the NPK granulator.
Post-granulation equipment determines the quality of the final product. In wet granulation processes, a drum dryer follows the granulator, using hot air to evaporate internal moisture from the granules, which lowers the product's moisture content and prevents caking during storage. The hot granules are then fed into a rotary cooler to rapidly reduce their temperature, preventing residual heat from causing moisture re-absorption. A drum screen (trommel screen) classifies the material, separating granules that are too large or too small; non-compliant material is returned to the beginning of the process for re-granulation, while standard 2–4mm granules are selected. A coating machine can apply an anti-caking agent to the surface of the granules, enhancing the fertilizer's flowability and extending its shelf life. Finally, an automated packaging machine handles precise weighing, bagging, and sealing, enabling the fully automated packaging and dispatch of the finished product.
Beyond the primary processing machinery, the entire production line also relies on essential auxiliary systems for conveying, dust removal, and electrical control. Belt conveyors and bucket elevators facilitate the transfer of materials between various process stages, enabling continuous production. Pulse-jet dust collection systems capture dust generated during crushing and screening, thereby improving the workshop environment and meeting environmental compliance standards. A comprehensive electrical control system centrally manages all equipment, allowing for the unified adjustment of operating speeds, temperatures, and ingredient proportions, which reduces the complexity of manual operation.
The auxiliary equipment required for NPK granulation varies depending on the specific process. Wet granulation methods—such as those using rotary drums or disc granulators—require a full suite of drying and cooling equipment, whereas dry granulation via roller compaction eliminates the need for drying and cooling, resulting in a simpler configuration. When selecting equipment, enterprises should consider their production capacity, available space, and chosen process route to ensure that all components are appropriately matched; this prevents production bottlenecks caused by capacity mismatches. A well-designed equipment configuration enhances the granulation rate, lowers energy consumption, and ensures the long-term, stable operation of the NPK compound fertilizer production line.