Industry Info

Discussion on improving the sphericity and roundness of NPK compound fertilizer

 Rotary drum granulator machine to produce NPK compound fertilizer is a process to achieve thermal granulation. By increasing the temperature of the material and increasing the solubility of the granulated water-based material, it is possible to obtain a liquid that meets the granulation requirements of the material at low moisture content. The number of phases reduces the heat energy consumption of the drying process and increases the production capacity of the equipment.Therefore, the quality of the granulation performance is the key to determining the yield and quality of the NPK fertilizer production.This article will discuss how to improve the granulation performance.

First, the time and frequency of the material rolling in the fertilizer granulator machine is the primary factor determining the ball rate and the roundness of the particles.
The principle of rotary drum granulator is that the material relies on surface tension, proper liquid phase, and the pressing force generated by rolling between materials, and the material in the correct direction of movement in the granulator with small particles as the core, sucking in the rolling Small attached, bonded into a ball. The higher the frequency of rolling in a certain period of time, the higher the sphericity rate and the more rounded the pellets are formed.

Second, the stable material volume and uniform liquid phase distribution in the drum granulator is the key to manufacturing qualified particles.
The design of the rotary drum granulator machine for NPK compound fertilizer production is to embed a steam pipe in the material bed, and to place a spray water pipe above the material bed. In the case where the production supply is stable, the saturated steam provides a part while providing heat and moisture to humidify the material.Through the use of steam, the temperature of the material and the viscosity of the material are improved, so that the water content of the material can be reduced during the ball forming process, thereby reducing the drying load, and the steam can be evenly distributed than the liquid phase of the added water. Adding water is a supplementary means only when the liquid phase of the material is insufficient and the material is unstable. During the NPK fertilizer production process, we encountered that the installation of the steam nozzle is unreasonable, the liquid phase distribution of the material is not uniform, and the material liquid phase is stuck in a large ball. Where the liquid phase is insufficient, the material is difficult to form a ball, which affects the formation of particles. In this case, we can increase the steam nozzle to increase the gas receiving area of the material.

Third, a reasonable material structure is the basis for improving the rate of formation
The material structure mainly refers to:
1. Reasonable combination of fineness of raw materials.
2. Reasonable combination of adhesive materials and dispersible materials.
3. The chemical reaction between materials should be considered in the formulation.
4. The comprehensive water content after mixing the materials.
5. Reasonable amount of return.

In short, the important principle of drum granulation for the NPK fertilizer production is to minimize the addition of moisture during granulation, moderately increase the temperature and solubility of the material, thereby reducing the heat energy consumption, improving the pass rate of the ball, increasing the output, and reducing the production cost.