Tower granulation process is the mainstream technology of modern compound fertilizer production, the core of which is to fall the molten fertilizer from a high altitude through the tower granulation device, cooling and solidifying into particles during the landing process. This article will be from the whole to the local, detailed introduction to the high tower granulation fertilizer plant facilities and their role.
Tower granulation process mainly contains six major processes: raw material treatment, melt mixing, granulation molding, cooling and sieving, coating treatment, and packaging of finished products. Raw materials enter the melt mixing system after pretreatment, and then form granules through the granulation device, get the finished products after cooling and sieving, and finally carry out film coating and packaging. The whole process can usually achieve more than 95% utilization rate of raw materials and more than 98% qualified rate of finished products.
1. Raw material pretreatment system
The raw material pre-processing system includes crusher, screening machine and metering equipment. The crusher crushes the raw materials to the specified size of 1-3mm, the screening machine ensures the uniformity of the raw material size, and the metering equipment accurately controls the ratio of raw materials, with the error controlled within ±0.5%. The system ensures that the raw material meets the process requirements and provides qualified raw materials for subsequent processes.
2. Melt mixing system
The melt mixing system consists of a melting furnace, a mixing tank and a transfer pump. The melting furnace heats the solid raw materials to a molten state of 110-130℃, the mixing tank realizes the homogeneous mixing of various raw materials, the homogeneity of mixing can be up to 99%, and the conveying pump conveys the mixed slurry at a flow rate of 10-15m³/h to the granulation device. This system ensures that the raw materials are fully melted and mixed to form a uniform slurry.
3. Tower Granulation
The tower granulation unit consists of a pelletizing nozzle, a pelletizing tower and an air conditioning system. The granulation nozzle disperses the molten slurry into 1-4mm droplets, the granulation tower is usually 60-120 meters high to provide sufficient landing height, and the air conditioning system controls the temperature in the tower at 50-70°C and the humidity at 30-50%. The device achieves granulation of the slurry to form uniform spherical particles with a particle strength of 15N or more.
4. Cooling and screening system
The cooling and screening system consists of a cooler, a sifter and a return conveyor. The cooler reduces the temperature of the pellets from 80-100°C to less than 40°C, the sifter separates the qualified and unqualified pellets, the qualified pellets are in the range of 2-4.75mm, and the return conveyor belt returns the unqualified pellets back to the raw material system, with the return rate usually controlled to less than 5%. This system ensures that the pellets are cooled quickly to obtain a uniform finished product.
5. Coating system
The coating system consists of a coating machine and a dryer. The coating machine forms a 0.1-0.3mm thick protective film on the surface of the granule, and the amount of coating material added is usually 1-3%. The dryer removes solvents from the coating material, and the moisture content of the granule is less than 1% after drying. This system improves the slow-release performance and storage stability of the fertilizer, and the slow-release period can reach 2-3 months.
6. Finished product packaging system
Finished product packaging system consists of weighing scale, packaging machine and palletizer. The weighing scale weighs accurately and the error is controlled within ±0.2%, the packing machine completes bagging with a packing speed of 600-1200 bags/hour, and the palletizer realizes automatic stacking with a stacking height of up to 2.5 m. The system ensures accurate packing of finished products for easy storage and transportation. The system ensures accurate packaging of finished products and facilitates storage and transportation.
Tower granulation process has the advantages of uniform particles, uniform distribution of nutrients, high particle strength, good solubility and so on. Its core lies in the use of gravity to achieve particle molding, with precise temperature and humidity control to ensure stable product quality. The annual capacity of a typical tower granulation line can reach 200,000-300,000 tons, and the energy consumption is about 50-70kWh/ton, which reduces the production cost by 10-15% compared with the traditional process.
Through the scientific configuration of the above facilities and precise control of the tower granulation process, the high tower granulation fertilizer plant can efficiently produce high-quality compound fertilizer products to meet the needs of modern agriculture.
If you are planning to start your tower granulation process project, or upgrade your existing project, please feel free to contact us, Lane is looking forward to cooperating with you!
