The time and frequency of material rolling in the rotary drum granulator are the primary factors to determine the pelletizing rate and particle roundness. The roundness of granular product in fertilizer production line can be improved by controlling the drum granulator.
Production principle of rotary drum granulator
Materials rely on surface tension, proper amount of liquid phase, extrusion force generated by rolling between materials, and correct movement direction of materials in the granulator, with small particles as the core, they absorb and adhere to each other and form balls in rolling. In a certain period of time, the higher the rolling frequency is, the higher the spheroidization rate is, and the rounder the particles are.
In the process of production, we have encountered two kinds of situations due to the different friction between materials and the wall of granulator.
1. The internal surface finish of granulator is large, so that the friction force between material and cylinder wall is reduced, and the upward movement force of material is weakened. If the material does not roll, it will not produce particles. In view of this situation, we can solve this problem by adjusting the speed of the granulator and installing a small plate inside.
2. The material in the drum granulator is severely stuck to the wall, and the friction between the material in the granulator and the wall of the barrel is increased, which raises the material in the machine too high, causing the material to fall from the top, so that the formed particles are not Rounding and excessive large particles, we think there are two reasons for this situation: on the one hand, the material is caused by too much viscous material, in this case, we change the formula of the npk production line to reduce the amount of viscous material; on the other hand , The inside of the granulator is not smooth. In this case, we change the internal material to increase the smoothness of the granulator.
On the other hand, we should also control the reasonable amount of material returned to the whole fertilizer production line. The process of rotary drum steam granulation is different from that of general fertilizer granulator, the relative pelletizing rate is lower, and the amount of returned material is higher. The amount of returned material directly affects the output and quality. The product has less particles, more powder and larger amount of return material, which directly affects the output. Large particles return more materials, directly affect the smoothness and roundness of the product.