During continuous operation, NPK fertilizer production lines are susceptible to factors such as raw material characteristics, equipment status, and process parameters, leading to various problems that directly impact product quality and production efficiency. The following are three typical problems and their solutions.

Raw material pretreatment often faces the challenge of uneven particle size. Nitrogen, phosphorus, and potassium raw materials vary significantly in hardness and moisture content. For example, urea easily absorbs moisture and clumps, while phosphate slag has a high hardness. Using only a single crusher can result in significant particle size variation, leading to uneven nutrient distribution during subsequent mixing. The solution requires "classified crushing + precise screening": urea is crushed with a hammer crusher, while phosphate slag is crushed with a crusher. After crushing, the raw materials are graded using multiple vibrating screens to ensure a uniform particle size within the appropriate range, significantly improving mixing uniformity.
Low particle formation rate is a frequent problem in the granulation process. During drum granulation, excessive water spraying can easily cause sticking to the wall and clumping. Excessive water spraying results in loose, fragile particles, resulting in a low particle formation rate. This problem requires dynamic parameter control: A humidity sensor is installed at the drum inlet to monitor the moisture content of the raw materials in real time. The spray volume is automatically adjusted via the PLC system based on moisture content changes. Furthermore, the drum speed is controlled based on raw material characteristics, and the internal lifter angle is adjusted to significantly improve the yield and maintain stability.
Product clumping is a prominent issue after drying and cooling. If the pellet moisture content does not drop to the acceptable standard after drying, or if the temperature difference during cooling is too large, the clumping rate will increase significantly over a period of storage. A two-pronged approach is necessary: ​​first, optimizing the drying process by implementing staged temperature control in the drum fertilizer dryer to ensure that the pellet moisture content at the outlet meets the standard. Second, upgrading the cooling system by using a dual-stage cooling system with air and water cooling to quickly reduce the pellet temperature to near room temperature. Adding an appropriate amount of anti-caking agent can effectively reduce the clumping rate.
Solving these problems requires dynamic adjustments based on the actual operating conditions of the NPK fertilizer production line. Through "precise control + equipment upgrades," this approach can not only ensure product quality meets standards, but also improve the continuous operation stability of the production line and reduce production costs.