In the modern agricultural fertilizer production chain, the disc granulator is a key piece of equipment for converting raw materials into granular fertilizer. It transforms loose fertilizer powder into uniform granules by simulating the principle of natural granulation, improving both the convenience of fertilization and the control of nutrient release rate. Its workflow mainly consists of four core stages.
First is the raw material pretreatment stage. Workers mix basic nutrient raw materials such as nitrogen, phosphorus, and potassium with binders such as clay and humic acid in a specific ratio, while simultaneously controlling the material's moisture content to 25%-35% using a humidifier. This step is fundamental to granulation; too low a moisture content will result in loose, easily broken granules, while too high a content will cause the material to adhere to the inner wall of the disc, affecting granulation efficiency.
After entering the core granulation stage, the pretreated mixture is conveyed into a rotating disc with an inclination angle of 35°-55°. The disc rotates steadily at a speed of 15-30 revolutions per minute. Under the combined action of centrifugal force, gravity, and friction, the material spirals upwards along the inner wall of the disc. With continuous tumbling, the fine powder gradually agglomerates into spherical particles with a diameter of 1-5 mm, gradually increasing in size like a snowball, eventually overflowing from the edge of the disc, completing the initial granulation.
After granulation, the particles need to enter a drying and solidification process. The freshly produced wet particles have a high moisture content and must be immediately sent to a dryer for continuous drying at a low temperature of 60-80℃. This step not only removes excess moisture from the particles but also stabilizes the internal nutrient structure, preventing clumping during storage. The dried particles are still at a high temperature and need to be cooled to room temperature by a cooler to prevent condensation during subsequent packaging.
Finally, there is a screening and recycling process. The cooled particles are screened by a vibrating screen. Particles that meet the specifications are sent to the packaging line, while oversized or undersized particles are crushed and returned to the granulation disc, achieving raw material recycling. This closed-loop design increases raw material utilization to over 95%, significantly reducing production costs.
As a key piece of equipment in fertilizer production lines, the disc granulator, with its simple structure, low energy consumption, and highly uniform pellets, has become a mainstream tool in the production of organic and compound fertilizers, providing crucial support for the efficient development of modern agriculture.