2026/01/28
The drum fertilizer dryer is a critical piece of equipment in modern fertilizer production, specifically designed for drying various fertilizer materials. Whether it's granular compound fertilizer, organic fertilizer, bio-organic fertilizer, or other types, this efficient drying equipment can quickly remove excess moisture through precise temperature and airflow control, ensuring the final product meets ideal moisture content standards (typically below 2%).
Working Principle: The Perfect Combination of Heat, Material, and Rotation
The basic workflow is as follows:
Feeding System: Moist fertilizer granules are continuously and evenly fed into the dryer's inlet via belt conveyor equipment.
Rotary Drying Process: Material enters the slowly rotating drum (typically 3-8 RPM). Internally, specially designed lifting flights constantly lift and shower the material, forming an even curtain of particles.
Hot Air Contact: High-temperature hot air (from gas, coal, or biomass hot air furnaces) passes through the drum co-currently or counter-currently, making full contact with the dispersed wet material for efficient heat and mass transfer.
Moisture Evaporation: Moisture in the material rapidly evaporates under heat energy. The hot, humid exhaust gas is discharged through a dust removal system.
Product Discharge: The dried fertilizer is discharged from the drum end for the next processing stage.
Equipment Structure: A Precisely Designed Drying System
Main components include:
Rotating Drum: The main body, made of quality steel plates, lined with wear-resistant material, with adjustable inclination (typically 1-5°).
Drive Unit: Motor, reducer, and gear transmission system providing smooth rotational power
Supporting Device: Riding rings, support rollers, and thrust rollers supporting the drum and allowing for thermal expansion.
Flight System: Specially arranged internal lifters optimizing material distribution and heat exchange.
Hot Air System: Hot air furnace, inlet ducting, and combustion unit providing a stable heat source.
Dust Removal System: Cyclone dust collector, bag filter, or wet scrubber treating the exhaust gas.
Control System: Automatic monitoring and adjustment of temperature, rotation speed, and feed rate.
Main Types and Characteristics
1. Direct-Heated Rotary Drum Dryer
Hot air directly contacts the material, offering high thermal efficiency (up to 70-80%). Suitable for drying fertilizers with less stringent cleanliness requirements, such as organic or compound fertilizers.
2. Indirect-Heated Rotary Drum Dryer
Hot air heats the drum shell through a jacket, transferring heat to the material by conduction, avoiding product contamination. Suitable for high-grade specialty or bio-fertilizers.
3. Combined Drying System
Incorporates advantages of both direct and indirect heating, often equipped with waste heat recovery for significant energy savings. Ideal for large-scale continuous production lines.
Technical Parameters and Selection Points
Key parameters include:
Capacity: 1-50 tons/hour (model dependent)
Initial Moisture Content: Typically handles materials with 15-35% wet basis moisture.
Final Moisture Content: Can be reduced to 1-5%, suitable for storage.
Operating Temperature: Inlet air 200-600°C, Exhaust air 80-120°C.
Heat Consumption: Approximately 900-1200 kcal required to evaporate 1kg of water.
Equipment Size: Diameter 1-3.5 meters, Length 6-30 meters.
Considerations for selection:
Material characteristics (particle size, heat sensitivity, stickiness)
Capacity requirements and production continuity
Available heat source type (natural gas, coal, steam, electricity)
Environmental requirements and emission standards
Site limitations and installation conditions
Application Advantages: Why Choose a Rotary Drum Dryer?
High Processing Capacity: Enables continuous, large-scale processing of various fertilizers for industrial production.
Uniform Drying: Rotation and flight design ensure each particle is fully exposed to hot air.
Strong Adaptability: Can handle many fertilizer types by adjusting speed, angle, and temperature.
Stable Operation: Simple and reliable mechanical structure with relatively low maintenance costs.
High Thermal Efficiency: Modern heat recovery systems can increase overall thermal efficiency to over 85%.
Excellent Product Quality: Precise temperature control prevents over-drying or caking
Practical Application Scenarios