The drum granulation method in the npk fertilizer production line
is a method of mixing and granulating powdered basic fertilizers with a drum granulator, which is widely used in the granulation of compound fertilizers.
Principle: First, each basic fertilizer is screened separately, and the screened material is crushed by a crusher and then screened. The under-sieve is sent to their respective hoppers. When the granulation system is in operation, the basic fertilizers are simultaneously sent from their respective hoppers to the feeding hopper via metering equipment, conveying equipment and lifting equipment according to the proportioning requirements. At the same time, the returned material enters the hopper together with the basic fertilizer through the lifting equipment. The basic fertilizers and returned materials are mixed to a certain extent in the process of transportation and lifting, but it is more ideal if a mixing device can be added. The mixture in the hopper is fed to the drum granulator
at a certain feeding speed. At the same time, the saturated steam is properly introduced below the material layer, which not only increases the temperature of the material, but also humidifies the material, which is conducive to granulation. If necessary, sprinkle a small amount of water or fertilizer solution on the material to maintain the best liquid phase amount for material granulation. The material forms a rolling material bed by the friction generated by the rotation of the drum granulator. The extrusion force generated by rolling makes the material containing a certain liquid phase agglomerate into small particles. These small particles become the core and adhere to the surrounding powder. Form larger particles. Because the drum granulator generally inclines 1°~2.5° to the discharge end, the granules slowly roll toward the discharge port while rotating with the cylinder. Qualified pellets leave the drum granulator and then enter the dryer for drying, and then go through screening, cooling, coating, packaging and storage. After being crushed, the on-screen material and the under-screen material are sent to the hopper as the return material and the basic fertilizer is granulated at the same time.
Characteristics of Rotary Drum Granulation Production Line
1. Technological innovation, structural improvement, reasonable process layout, advanced technology and low production cost.
2. Drum granulation is characterized by high wear resistance, convenient maintenance, high ball forming strength, good appearance quality, corrosion resistance, wear resistance, low energy consumption, long service life, convenient operation and maintenance, etc.
3. High balling rate, high drying efficiency, balling rate up to 90%, with a small amount of returned material, the particle size of returned material is small, it can be re granulated; steam heating is introduced to improve the material temperature.
4. Reasonable layout, leading technology, small power, no three waste discharge, stable operation, convenient maintenance.