The NPK fertilizer production line is a production system that processes the three main nutrients of nitrogen, phosphorus, and potassium through a series of processing steps to ultimately produce granular or powdered compound fertilizers. The process usually includes the following steps:
1. Raw material preparation and pretreatment
Raw material measurement: Based on the target fertilizer formula, use measuring equipment to accurately weigh raw materials such as urea (N), phosphate (P), potassium salt (K), etc.
Raw material crushing: Send large pieces of raw materials into a crusher and crush them into particle sizes suitable for mixing.
2. Raw material mixing
Mixing: Feed the measured raw materials into a mixer, such as a double shaft blade mixer or a V-type mixer, and use mechanical force to thoroughly mix the raw materials evenly.
3. Granulation
Moisturizing with water: According to the granulation needs, add an appropriate amount of water to the mixture to achieve a suitable humidity for the raw materials, which is beneficial for granulation.
Granulation: Use a granulator, such as a disc granulator, drum granulator, or extrusion granulator, to make granules from the evenly mixed raw materials. The working principle of a granulator is usually to use rotation or pressure to form particles of a specific size and shape from the raw materials.
4. Drying
Drying: After granulation, the wet particles need to be sent to a drying machine, such as a fluidized bed dryer or a rotary drum dryer, to remove moisture from the particles through hot air or other drying media, preventing the particles from clumping during storage and transportation.
5. Cooling
Cooling: The dried particles have a high temperature and need to be cooled to a suitable temperature through cooling equipment, such as a cooling drum, to prevent the high temperature from affecting the fertilizer performance and facilitate subsequent processing and packaging.
6. Screening
Screening: After cooling, the particles are sieved through an organic fertilizer screening machine to select particles that meet the particle size requirements. Larger particles may need to be re pelletized, while smaller particles may be treated as dust or reused.
7. Capsule (optional)
Coating: In order to improve the moisture resistance of fertilizers and control nutrient release rate, some production lines will apply coating treatment to qualified particles after screening, usually using a coating machine to coat a layer of organic or inorganic film on the surface of the particles.
8. Packaging
Automatic packaging: Finally, the finished fertilizer is weighed and packaged using an automatic packaging machine to form finished fertilizer bags, ready for storage or shipment.
9. Control and Monitoring
Automation control: The entire NPK fertilizer production line is usually equipped with advanced PLC control systems and automation instruments to monitor and adjust key parameters in the production process, such as raw material ratio, granulation humidity, drying temperature, etc., to ensure the stability of the production process and the quality of the product.
Through the above process flow, the NPK fertilizer production line can efficiently and accurately produce high-quality compound fertilizers that meet agricultural needs and meet the nutritional requirements of different crops and soils.