What is the working principle of disc granulator machine?

The disc granulator, a core piece of equipment in a fertilizer production line, operates on the principle of material agglomeration and granulation. Its core principle is to transform powder into granules by leveraging the synergistic effects of mechanical force and the physical properties of the material. The equipment primarily consists of an inclined disc, a transmission system, a distribution device, a water spray system, and a frame. The inclined disc is the core granulation component, typically tilted at a 45-60° angle, and its rotational speed can be adjusted according to the material's characteristics. During operation, the distribution device evenly conveys the powdered material to be granulated (such as fertilizer raw materials or mineral powder) into the rotating disc. Driven by a motor, the disc then moves in a circular motion. Centrifugal force, gravity, and friction combine to cause the material to spiral upward along the disc's inner wall, laying the foundation for subsequent granulation. Once the material has established a stable trajectory within the disc, the water spray system begins to apply an appropriate amount of water or binder. The water moistens the powder surface, forming a cohesive "core" of tiny particles. This step is known as the "nucleation stage." As the disc rotates continuously, the small particle cores constantly collide with and attract surrounding powder materials, gradually growing larger like a snowball. During this process, the disc's tilt angle and rotational speed are precisely coordinated: too fast a rotational speed will cause the material to be ejected due to excessive centrifugal force, while too slow a rotational speed will not provide sufficient collision energy. A too large tilt angle will cause the material to slide too quickly, while too small an angle will result in excessive retention time. These factors together determine the efficiency and uniformity of granulation. When the particles reach the desired size (typically 1-10mm), their own gravity overcomes the combined forces of centrifugal force and friction, causing them to automatically roll off the edge of the disc and enter the subsequent drying and screening stages, completing the granulation process. The disc granulator machine utilizes the principle of "rotational agglomeration," which not only ensures uniform granule shape and high strength, but also offers low energy consumption and high adaptability. Process parameters can be adjusted to suit different material characteristics to meet diverse granulation production needs.