2026/10/19
A: Rotary drum granulators handle large-volume production (70%-80%), while disc granulators handle small-batch custom orders.
The combination of disc granulators and rotary drum granulators is a classic approach for fertilizer production lines, balancing large-volume production with small-batch custom orders. The industry practice is for rotary drum granulators to handle 70%-80% of large-volume production, while disc granulators handle 20%-30% of small-batch, multi-variety custom orders. This division of labor leverages the high capacity of rotary drum granulators while retaining the flexibility of disc granulators, making it particularly suitable for organic fertilizer or compound fertilizer companies with an annual production capacity of 30,000-100,000 tons and a diverse product line.
I. Why use rotary drum granulators for large-volume production (70%-80%)?
A single rotary drum granulator can achieve an hourly output of 8-15 tons, with larger models reaching 20-30 tons, and can operate continuously for 24 hours. It relies on the rotation of the drum and steam humidification, resulting in a long residence time of materials inside the drum, high pelleting rate, and high granule strength, making it suitable for large-scale production of standardized general-purpose fertilizers. In production lines with an annual output of over 50,000 tons, a single rotary drum granulator can meet the main production capacity requirements, with the lowest cost per ton. Therefore, allocating 70%-80% of the capacity to rotary drum granulators is a rational choice for pursuing economies of scale.
II. Why do disc granulators accept small-batch customization?
Disc granulators have a single-machine output of 1-5 tons per hour, low investment, flexible start-up and shutdown, and quick formula changes. It utilizes the rolling friction and atomized spray of an inclined disc to form pellets, resulting in round and full granules with a particle size that can be flexibly adjusted within the range of 2-8mm. When customers require specialized fertilizer formulas, customized fertilizers for cash crops, or small-batch trial production, disc granulators can be quickly switched without the need for lengthy parameter adjustments and line cleaning like rotary drum granulators. For multi-variety, small-batch orders, the flexibility of disc granulators is something rotary drum granulators lack.
III. How to scientifically combine formulas? The core of this integrated approach is "shared front end, separate granulation, and shared back end." The front-end batching, mixing, and crushing systems share a single system to ensure consistent raw materials. The granulation process is divided into two lines: a rotary drum line handles general-purpose base fertilizers, while a disc line handles customized formulations. The back-end drying, cooling, screening, and packaging processes can also be shared, simply connecting to the same post-processing system after granulation. This saves investment and improves equipment utilization.
Specific ratio recommendations: For an annual production of 100,000 tons, the rotary drum line should handle 70,000-80,000 tons, and the disc line 20,000-30,000 tons. Use 1-2 large-scale rotary drum machines and 2-3 medium-sized disc machines in parallel. In terms of production planning, the rotary drum line operates continuously, while the disc line operates intermittently according to orders, without interference.
IV. Three Major Benefits of this Integrated Approach
First, lower investment: Saves over 30% on equipment investment compared to two independent production lines.
Second, more flexible delivery: Large-volume orders are on time, and small-batch customization can also be accepted.
Third, superior quality: General-purpose fertilizer granules have high strength, and customized fertilizer granules are rounder, each leveraging its strengths.
V. Conclusion The combination of disc granulators and rotary drum granulators is not a simple addition, but a strategic division of labor between capacity and flexibility. Rotary drum granulators handle large-volume production (70%-80%), while disc granulators handle small-batch custom orders. This model has been validated in many medium-sized fertilizer plants. When selecting granulators, it is recommended to first clarify the product structure: if general-purpose fertilizers account for a high proportion, increase the proportion of rotary drum granulators; if there are many custom orders, increase the number of disc granulators. The optimal solution for production line configuration is to let each type of granulator do what it does best.