The double roller granulator is a common fertilizer granulator machine in fertilizer production. Compared with the wet granulation method, there is no need to add water when the granulator is used to produce fertilizer. This dry granulation method does not require the whole production line to be equipped with large-scale equipment such as dryer and cooler, which simplifies a lot in fertilizer production process and greatly reduces equipment investment. Therefore, in the production of compound fertilizer, investment in a roller extrusion granulation production line is also very suitable, the price is more cost-effective.
1. Batching and mixing.
Fertilizer raw materials such as urea, ammonium phosphate and potassium chloride can be mixed by a mixer placed under the ground, and even mixing can be realized by using a horizontal mixer or a vertical mixer. The two mixers are batch mixing and discharging operation, so two mixers can be equipped at the same time, so they can be used alternately to achieve continuous discharging.
2. Extrusion granulation.
Double roller fertilizer granulator is used in this process, and the mixed fertilizer mixture is extruded by the opposite roller extrusion granulator to form elliptical particles. The principle of the double roller granulator is to extrude the materials filled in the mold to form the finished particles. When used, the mixed material is added into the gap between two opposite rotating roller shafts through a vertical screw feeder. During the extrusion process, the pressure of the material increases gradually. When the gap between the two shafts is a very small position, the pressure of the material is relatively large, and then decreases gradually until 0. In the extrusion process, the apparent density of the mixture can be increased by 1.5-3 times due to the reduction of the empty volume of the material. After extrusion, the product is usually a large plate with a thickness of 5-20 mm. The structure and size of the roller granulator are determined by many parameters, which are generally determined by material properties and experiments. Finally, the particles formed by the materials enter the next stage of the process.
3. Screening and packaging
After screening and packaging, the particles become finished fertilizer.