Discussions on selecting fertilizer equipment usually focus on production capacity, power, and price, yet one variable is systematically overlooked: the climatic conditions of the installation site. The same organic fertilizer disc granulator might operate smoothly in Guangdong but suffer from frequent material sticking and substandard granule strength when moved to Heilongjiang. This is not an issue of equipment quality, but rather the profound impact of ambient temperature and humidity on the granulation process.
High-humidity environments in the South: Moisture gets in but cannot get out. Regions like Guangdong, Guangxi, and Fujian often experience relative humidity levels above 75% year-round, reaching up to 90% during the rainy season. Disc granulators rely on the material’s inherent moisture to roll into pellets; however, high ambient humidity causes the material to continuously absorb atmospheric moisture during mixing and granulation, resulting in an actual moisture content that exceeds the target setpoint. The result: granules grow excessively large and clump together, while material adhesion to the disc surface intensifies. Furthermore, drying granules is difficult in high-humidity conditions; if the dryer’s intake temperature or airflow volume is insufficient, the final moisture content struggles to drop below 15%, leading to moisture absorption and caking after packaging. Countermeasures: Reduce the water spray volume during mixing to keep the input moisture content at the lower end of the target range; install dehumidifiers in the granulation workshop to maintain ambient humidity below 60%; and employ a high-airflow strategy in the dryer to compensate for lower temperatures.
Dry, cold environments in the North: Moisture is lost too quickly. In Northeast and Northwest China, low winter temperatures and dry air cause rapid moisture evaporation during material mixing and transport. By the time the material enters the disc granulator, the surface is already too dry, making pellet formation difficult and causing fine dust to scatter. Additionally, material adhesiveness decreases in low temperatures; granules struggle to stick together and grow while rolling on the disc, causing the pelletization rate to drop from over 90% (typical in the South) to below 70%. If the workshop lacks heating, moisture sprayed into the mixer may freeze locally, causing the material to clump and clog the equipment. Countermeasures include: slightly increasing the spray volume during mixing; installing warm air blowers or steam coils in the granulation workshop to maintain an ambient temperature above 15°C; adding insulation to conveying pipelines to minimize moisture evaporation; and appropriately reducing the rotation speed of the granulation disc to extend the material’s residence time.
The new “two-in-one” granulator offers superior climate adaptability. By integrating mixing and granulation into a single main unit, this machine minimizes the transfer time between the mixing and granulation zones and reduces the material’s exposure to ambient air, thereby lessening the impact of external temperature and humidity. It accommodates a wide range of input moisture content (25%–45%), making it suitable for both the dry climates of the north and the high-humidity environments of the south. However, success depends on the semi-wet material being pulverized to the required fineness and fermented uniformly beforehand. If the pulverization is insufficient or the moisture content falls outside the optimal range, the machine may still experience disc adhesion or a drop in granulation efficiency.
Granulating bio-organic fertilizer involves an additional constraint: the temperature must not exceed 55°C throughout the process. In southern workshops during summer, ambient temperatures often exceed 35°C; when combined with frictional heat generated during granulation, the temperature can easily surpass the critical limit. The situation is reversed in the north during winter: while low ambient temperatures facilitate temperature control, the material tends to be too dry, resulting in poor granulation rates. Conversely, increasing the spray volume to improve granulation can lead to excessive moisture, thereby extending the time required for low-temperature drying and reducing overall output.