In the NPK fertilizer production process, equipment failures can easily lead to reduced production capacity, substandard product quality, and even increased maintenance costs. The following provides precise troubleshooting solutions for three common faults: inaccurate ingredient mixing, poor granulation, and poor drying effect, helping to ensure efficient production operation.

Inaccurate ingredient mixing is the core fault affecting fertilizer quality, manifested as a deviation of the nitrogen, phosphorus, and potassium ratio from the set value, with an error exceeding ±1%. The main causes include: raw material residue adhering to the weighing sensor, drift in the variable frequency speed control system parameters, and uneven feeding due to blockage at the hopper discharge port. To resolve this, first stop the machine and clean the sensor, then recalibrate it using calibration weights; check the variable frequency controller parameters and verify and correct them against the set ratio; clean the accumulated material at the discharge port and adjust the vibration feeder amplitude to ensure uniform material flow. Routinely, the sensor should be calibrated weekly to avoid residue buildup affecting accuracy.
Poor granulation results in loose, unevenly sized, or clumped particles, primarily caused by insufficient mixing, improper moisture control, or abnormal rotation speed of the NPK fertilizer granulator machine. Troubleshooting begins with checking the wear of the mixing blades; if deformed, replace them immediately. Adjust the raw material moisture content to a suitable range of 25%-30%; if too dry, spray humidification; if too wet, add drying agents. Fine-tune the granulator speed based on the granulation effect, generally controlling it at 30-50 rpm. Regularly clean any adhering material from the granulator's interior to prevent affecting the granulation process.
Poor drying leads to excessive fertilizer moisture content, making it prone to mold and clumping. This is mainly caused by abnormal drying temperature, insufficient hot air volume, or uneven material distribution. First, check the temperature control system to ensure the drying temperature is stable at 80-100℃; clean dust from the hot air ducts and check the fan's operation to ensure sufficient airflow; adjust the conveyor belt speed to prevent excessive material buildup and ensure even heating. In addition, the inner wall of the drying drum needs to be cleaned daily to prevent residue from adhering and affecting heat transfer efficiency.
For NPK fertilizer machines, prevention is more important than maintenance. It is recommended to strictly follow the maintenance system of "daily cleaning, weekly inspection, and monthly calibration", pay special attention to vulnerable parts such as sensors, mixing paddles, and screens, and replace aging parts in a timely manner. This will not only reduce the failure rate but also extend the service life of the equipment and ensure the continuity and stability of NPK fertilizer production.