Compound Fertilizer Rotary Drum Granulation Production Line: 20 TPH Turnkey Project Case Study

Project Overview

This case study details the design, manufacturing, and commissioning of a compound fertilizer rotary drum granulation production line for a leading agricultural enterprise in South Asia. The client required a high-capacity 20 tons per hour (TPH) production line capable of manufacturing NPK compound fertilizers with precise nutrient ratios, utilizing the rotary drum granulation process for superior granule uniformity and strength.

Client Background

The client is a major fertilizer manufacturer in South Asia with an annual distribution network covering over 500 retail outlets. Facing increasing regional demand for customized NPK blends, the company decided to invest in a new compound fertilizer production facility to expand capacity and improve product consistency. Their existing batch-mixing operation could no longer meet the quality standards demanded by large-scale agricultural buyers.

• Industry: Compound fertilizer manufacturing
• Region: South Asia
• Project Scale: Full production line, 20 TPH capacity
• Project Type: New factory expansion

Client Requirements & Challenges

Solution Delivered

We supplied a complete rotary drum granulation production line with the following core configuration:

1. Raw Material Batching System — Automated weighing and dosing for urea, DAP, MOP, ammonium sulfate, and micro-nutrients with precision to ±0.5%.
2. Chain Crusher — Two-stage crushing to ensure uniform raw material particle size below 1 mm before mixing.
3. Double-Shaft Horizontal Mixer — Continuous mixing with controlled residence time to achieve homogeneous NPK distribution.
4. Rotary Drum Granulator (4.0m * 1.8m) — The core granulation unit featuring optimized lifter design, steam pre-conditioning, and variable-speed drive for precise control of granule size distribution (2–4 mm target).
5. Rotary Dryer (2.8m * 24m) — Co-current hot air drying with multi-zone temperature control, reducing moisture from 12–15% to below 2%.
6. Rotary Cooler (2.4m * 18m) — Counter-flow air cooling with integrated anti-caking agent spray system.
7. Double-Deck Vibrating Screener — Separating on-spec granules (2–4 mm), oversize (returned to crusher), and undersize (returned to granulator) for closed-loop recycling.
8. Rotary Drum Coating Machine — Surface treatment with colorant and anti-caking agents for enhanced product appearance and storability.
9. Automatic Weighing & Packing System — 50 kg bag filling station with heat-sealing and palletizing conveyor.
10. PLC Centralized Control System — Real-time process monitoring, automatic alarm handling, and production data logging for reliable line-wide automation.

Project Execution

Results & Key Metrics

Following commissioning and a 30-day performance guarantee period, the following results were verified:

• Throughput: Stable production at 20.5 TPH, exceeding the contractual target of 20 TPH.
• Granule Sphericity: 93.2% of granules achieved spherical shape with roundness score > 90%, minimizing breakage during handling and transport.
• Granule Crushing Strength: Average 28.6 N per granule, well above the 25 N specification, ensuring product integrity from factory to field.
• Formula Flexibility: Successfully switched between 15-15-15, 20-10-10, and 12-24-12 NPK grades with cleanup and changeover completed in under 4 hours.
• Recycle Ratio: Closed-loop system maintained recycle ratio below 25%, maximizing first-pass yield and reducing energy consumption.
• Environmental Performance: Stack emissions met local PM2.5 standards; dust concentration at discharge point was below 30 mg/m³.
• Operator Certification: All 15 operators completed training and independently ran the full line within the 2-week handover period.

Client Testimonial Highlights

"The rotary drum granulation technology delivered exactly what we needed — consistent, spherical, and strong granules that our customers immediately noticed. The ability to switch between NPK formulations in a single shift has transformed our production flexibility. The PLC control system gives us stable and reliable operation, and our quality complaints have dropped to nearly zero since switching to this line." — Plant Manager, Client Company

Conclusion

This project underscores our expertise in delivering high-capacity compound fertilizer rotary drum granulation production lines that combine robust mechanical engineering with intelligent process control. From precision batching and steam-assisted granulation to anti-caking treatment and automated packing, every stage is optimized for throughput, quality, and operational efficiency. Whether you need a dedicated NPK compound fertilizer line or a multi-purpose rotary drum granulation system capable of handling diverse formulations, we offer complete turnkey solutions backed by on-site installation, training, and long-term technical support.

For inquiries about our compound fertilizer equipment, please contact our engineering team for a customized proposal.