Targeted Solutions for Common Problems with NPK Fertilizer Granulators

For issues with pellet quality, yield, and blockage that arise during NPK fertilizer granulation, precise measures must be taken based on the underlying causes to quickly restore stable equipment operation.

To address pellet quality issues, precise control of two key variables—moisture content and rotational speed—is crucial. If pellet strength is insufficient, a moisture meter can be used to monitor the mixed raw materials in real time, maintaining a stable moisture content of 15%-20%—a range that ensures both pellet formability and hardness. If the moisture content is too high, the dryer temperature can be increased from 80°C to 90-95°C to accelerate moisture evaporation. If the moisture content is too low, water can be added at a rate of 5-8 liters per hour using an atomizing water sprayer installed at the feed inlet. To address uneven particle size, the speed should be adjusted based on the type of granulator. For a rotary drum granulator, the speed should match the drum diameter. For a 1.2-meter diameter machine, adjust the speed to 18-20 rpm, and for a 1.5-meter diameter machine, adjust the speed to 20-22 rpm. For a disc granulator, adjust the speed based on the disc's inclination angle (typically 35°-45°). The speed can be slightly higher (33-35 rpm) at higher inclination angles, and lowered to 30-32 rpm at lower inclination angles. Additionally, a spiral mixer should be installed at the feed inlet to ensure a uniform hourly feed rate within a 5% error, thus reducing particle size variation at the source.

To address a sudden drop in production, a step-by-step investigation and resolution is required. First, check the NPK raw material ratio. Use a component analyzer to confirm that the nitrogen, phosphorus, and potassium ratios meet the formulation requirements, and then adjust the batching system parameters. If core components are worn, the roller granulator rollers should be replaced or polished to restore the effective extrusion area. Check the fan's operating status and remove dust and debris from the air duct to ensure adequate airflow and prevent material accumulation from affecting production.

To address equipment blockage, address the feed and discharge ports separately and address them accordingly. If the feed port is blocked, install a vibrating screen at the feed port to filter out impurities and agglomerated materials with a diameter larger than 5mm. Regularly clean the feed channel. If the discharge port is blocked, increase the drying temperature by 5-10°C to reduce the moisture content of the pellets and prevent adhesion. At the end of each day's production, clean the inner wall of the discharge pipe with a high-pressure air gun to prevent residual material from clogging.

The above targeted solutions not only quickly resolve common granulator problems but also reduce the failure rate through standardized operations. According to actual case statistics, the equipment's continuous operation time can be extended by 30%, and operation and maintenance costs can be reduced by 15%, significantly improving the production efficiency of NPK fertilizer production lines.