The rotary drum granulator plays a crucial role in the NPK fertilizer production line, as it completes the granulation process of NPK compound fertilizer through an efficient wet granulation technology. The following are detailed granulation steps and principles:
Introduction to NPK Fertilizer
NPK fertilizer refers to a compound fertilizer containing three main nutrients: nitrogen (N), phosphorus (P), and potassium (K). It is widely used in crop cultivation to improve soil fertility and crop yield.
Working principle of rotary drum granulator
The core of a rotary drum granulator is a large drum shaped container that is tilted and slowly rotated, filled with the material to be granulated inside. This device utilizes a combination of centrifugal force and frictional force to promote the collision and agglomeration of materials during continuous rolling, ultimately forming uniform spherical particles.
Specific granulation steps
Raw material mixing: Firstly, accurately measure and thoroughly mix the pre proportioned basic fertilizer raw materials such as urea, diammonium phosphate (DAP), potassium chloride, etc. to ensure accurate distribution ratio.
Wetting and spraying: The mixed powdered raw materials are fed into a rotary drum granulator, while introducing an appropriate amount of water or other liquid binders to increase the adhesion between the materials.
Rolling forming: Under the slow rotation of the drum, the material begins to roll and gradually gather and increase, forming small balls with initial shape through the collision and aggregation between particles.
Growth and development: By adjusting the speed, angle, and time of the drum, the movement trajectory and dwell time of the material inside the drum are controlled, so that the small ball gradually grows to the required particle size.
Solidification: Heating may occur during the granulation process to help evaporate water and further enhance the stability of the particles; It is also possible to promote particle hardening by spraying a small amount of water vapor before discharging.
Cooling and screening: Finally, the particles are cooled down by a cooling tower and then separated into qualified products through a vibrating screen. Unqualified products are returned to the granulation area for reprocessing.
Key technical points
Material ratio: Ensure precise mixing of each component to achieve ideal fertilizer efficiency.
Adhesive selection: Reasonably select adhesives that promote particle formation without affecting fertilizer efficiency.
Controlling humidity: Moderate humidity is crucial for particle formation, as too high or too low can affect the quality of granulation.
Drum parameter tuning: including speed, tilt angle, filling rate, etc., directly affecting the size, strength, and appearance of particles.
Through careful design and precise regulation, the rotary drum granulation machine can produce uniform and sturdy NPK fertilizer particles, which not only improve the convenience of fertilizer storage and transportation, but also ensure the uniform application of nutrients, maximize fertilizer efficiency, and promote healthy crop growth.