The rotary drum granulation production process is a widely used method in the production of compound fertilizers. The following is a detailed introduction to its production process:

1、 Process flow

Raw material pretreatment:

Grind and mix the required raw materials to ensure uniform particle size and composition. These raw materials may include basic fertilizers such as nitrogen, phosphorus, potassium, as well as other additives.

Raw material moisture:

Moisturize the raw materials appropriately to achieve a suitable humidity for granulation. The purpose of wetting is to increase the viscosity between materials and promote the formation of particles. This step is usually achieved by adding a certain amount of water or steam.

Drum granulation:

Feed the wet raw materials into the rotary drum granulator. The rotary drum granulator is a tilted cylinder with a special structure inside to promote the rolling and squeezing of materials. Through the rotation of the cylinder, the material continuously rolls, rubs, and squeezes inside the cylinder, gradually forming particles. The ball formation rate is high, reaching about 70%, and the particle size of the returned material is small, which can be re granulated.

Particle drying:

Reduce the moisture content of the granulated wet particles through a drying device to achieve the specified drying degree. The purpose of drying is to improve the stability and storage of particles, and prevent agglomeration and deterioration caused by excessive moisture.

Particle cooling:

Cool the dried particles to lower their temperature and further improve their hardness and stability. Cooling can also prevent particles from breaking due to temperature changes during storage and transportation.

Particle screening:

By using screening equipment, particles that do not meet the standard size are separated to ensure product quality. Screening and grading can ensure that the particle size of the product is uniform and meets market demand.

Finished product packaging:

Pack and store the particles for easy transportation and sales. Packaging materials are usually chosen to be moisture-proof and damage resistant to ensure the safety and quality of the product during storage and transportation.

2、 Process characteristics

Low investment and high output: The rotary drum granulation production process has the characteristics of low investment and high output, making it suitable for large-scale production.

Strong adaptability: This process can adapt to the production of various types of fertilizers with relatively small formula limitations.

High quality of finished products: The particles produced by the rotary drum granulator are uniform, compact, and have good compressive strength and stability.

3、 Technical points

Control drum parameters: The inclination angle, speed, and other parameters of the drum have a significant impact on the formation and quality of particles. Usually, the inclination angle is controlled between 3 ° and 5 °, and the speed is adjusted according to the diameter (usually 10~20r/min).

Adjust moisture content: The moisture content of the raw materials should be controlled within a certain range (such as ≤ 5%) to prevent pre agglomeration. Meanwhile, an appropriate amount of liquid binder should be added during the granulation process to control local humidity.

Optimize the inner wall structure: The inner wall of the drum adopts diamond or wavy lining plates, which can enhance the material shear force and granulation effect.

Temperature control: The inlet temperature is controlled at 40-60 ℃, which can accelerate chemical reactions; The outlet temperature is regulated through ventilation to prevent nutrient loss (such as urea decomposition) caused by high temperatures.

Adjust granulation time: Adjust the granulation time according to the particle strength requirements (usually 5-15 minutes). If it is too long, it is easy to overfill, and if it is too short, it will become loose.

Control particle size distribution: Control the size of the discharge port through a sieve, classify and recycle the material for granulation, and ensure uniform particle size.

Strength testing: Particle strength is verified through drop testing (>95% intact particles) or pressure testing (>10N/particle).

Negative pressure system: Maintain a slight negative pressure inside the drum, combined with cyclone dust removal and bag filtration, with a recovery rate of>98%.