The core process of the high tower granulator is to use the "high-altitude cooling distance" provided by the high tower (usually 30-60 meters high) to allow the fertilizer melt to naturally solidify into particles during the falling process. The specific steps are as follows:

Raw material melting and mixing: Mix nitrogen (such as urea, ammonium nitrate), phosphorus (such as monoammonium phosphate), potassium (such as potassium chloride) and other raw materials according to the formula ratio, and send them to the melting tank (temperature 120-150 ℃) to heat them to a molten state, forming a uniform fertilizer slurry (moisture content should be controlled below 1% to avoid affecting particle strength);

High altitude spray atomization: The molten slurry is atomized into small droplets through the "rotating granulation nozzle" at the top of the tower (with a speed of 500-1500 revolutions per minute), and the droplet diameter can be precisely controlled by the nozzle aperture (usually 1-3mm) and speed;

Natural cooling forming: atomized droplets fall freely from the top of the tower (falling time is about 10-20 seconds), and during the process, they come into full contact with the rising cold air inside the tower, gradually cooling and solidifying into spherical or quasi spherical particles;

Particle collection and screening: The cooled particles fall into the collection hopper at the bottom of the tower, and are screened by a vibrating screen (removing a small amount of powder and oversized particles). Qualified particles enter the subsequent coating or packaging process.