The double roller extrusion granulator consists of one roll with opposite rotation direction, which is installed side by side with a small spacing. Generally, one roller is fixed and the other is relatively rotating. A certain number of die holes are engraved on the surface of each roll. The process of roller extrusion fertilizer granulation process

The powder material enters the hopper. With the continuous rotation of the roller, the material enters the arc triangle between the two rollers and is gradually compressed. When the roller reaches the geometric center line of the opposite roller, the fertilizer in the mold hole is pressed into fertilizer under the maximum pressure. When the roller rotates through the center line, there is sliding between the particles and the mold hole. Under the action of gravity, the granular fertilizer falls off from the mold hole. This extrusion process is purely volume compression, and the force is mainly related to the radius of the counter roll, die hole size and fertilizer filling degree. In addition, the full agitation before granulation and the screening in the later process, there is no temperature rise in the production of the whole process, and there is no need to dry and remove water, so that the material does not have chemical reaction, so the processing is very convenient.

Characteristics of fertilizer granulation process by roller extrusion
1. The double roll extrusion granulator is widely used in animal husbandry;
2. The particles produced are spherical;
3. The content of organic matter can be as high as 100%, realizing the granulation of pure organic matter;
4. The fertilizer pellet machine takes advantage of the characteristics that organic particles can be inlaid with each other and grow up under a certain force;
5. Solid particles can be sieved after granulation to reduce energy consumption of drying;
6. The organic matter after fermentation does not need to be dried, and the moisture content of raw material can be less than 15%.