As a key piece of equipment in a fertilizer production line, the rotary drum granulator‘s core operation revolves around “continuous pelletization and stable granulation.” Through the coordinated operation of multiple components, it achieves efficient conversion of raw materials into granules. The specific operation process can be divided into three stages.
The raw material pretreatment and feeding stage is the starting point. Crushed and mixed powdered raw materials (such as compound fertilizer raw materials) are fed into the drum body at a constant speed by a belt conveyor. At this point, the distribution plate installed at the feed end first activates, evenly spreading the raw materials on the inner wall of the drum to prevent local accumulation and uneven granulation. Simultaneously, the atomizing nozzle is activated to spray a fixed amount of binder (such as water or starch solution) onto the raw materials, establishing a moisture foundation for subsequent pelletization. This step requires precise control of the material-to-binder ratio and is crucial for ensuring granule quality.
The drum rotation and granulation forming stage are the core operations. The drum body rotates at a low speed of 5-15 rpm. The lifting plates on its inner wall rotate synchronously with the drum, continuously lifting the material from the bottom upwards. When the material is brought to a certain height, it slides down the lifting plate under the influence of gravity, forming a “throwing-tumbling” cycle. During this process, the moist powder particles continuously collide and bond, gradually agglomerating into small particles. As the drum continues to rotate, the small particles further densify through repeated friction and compression, ultimately forming uniform granules with a diameter of 2-6 mm. The drum’s tilt angle (typically 3°-5°) also drives the material slowly toward the discharge end, enabling continuous production.
The finished product separation and subsequent processing stages complete the closed-loop operation. The formed granules follow the material flow into the screening device at the end of the drum. The vibrating screen screens the qualified granules and conveys them to the drying system, while the fine powder is separated and returned to the feed end for granulation. Simultaneously, the support rollers and retaining rollers on the outside of the drum operate continuously. The support rollers support the drum’s stable rotation, while the retaining rollers prevent axial movement, ensuring a safe and orderly granulation process.
From raw material feeding to finished product output, the rotary drum granulator achieves efficient and continuous granulation of powdered materials through the continuous action of “distribution – rotation – pelletization – screening”. Its stable action mechanism has also become an important guarantee for particle formation in industrial production.