Rotary Drum Dryer for Fertilizer & Industrial Drying

Equipment in Action

In addition to fertilizer production lines, SYM can customize rotary drum dryers for a wide range of industrial drying applications. The equipment can be tailored to suit different applications and specific processing requirements.

Feature



Anti-Sticking & Optimized Flight Design

The drum internal structure is optimized to reduce material buildup. Flight design can be customized according to different fertilizer formulations to control material movement and residence time. For sticky materials, chain cleaners or knockers can be added to improve cleaning performance.



Flexible Heat Source Connection

The rotary dryer can be connected with different hot air furnaces, including coal, gas, oil, and biomass systems. This allows flexible energy selection based on operating cost and local conditions.



High Sealing Performance

Multi-layer sealing structures are used at the inlet and outlet to reduce air leakage. This improves thermal efficiency and ensures a stable drying environment.



Integrated Drying Process

The rotary drum dryer is designed to work with granulation systems. It ensures uniform moisture reduction while maintaining granule strength and particle size consistency.



Environmental Protection System

The exhaust gas can be treated by cyclone separator and bag filter, with optional wet scrubber for stricter emission requirements. This configuration effectively reduces dust and meets industrial standards.

Structure

Rotary Drum

The drum is the main working part of the rotary dryer. Materials are lifted and dried inside the rotating cylinder. Drum size determines capacity and drying time.

Lifting Flights

Flights installed inside the drum lift and scatter materials. Proper flight design improves heat exchange efficiency and drying performance.

Drive System

The drive system includes motor, reducer, girth gear, and pinion. It provides stable rotation and supports speed adjustment.

Support System

Tyres and rollers support the drum. This structure ensures stable operation and reduces mechanical stress.

Sealing Device

Installed between the drum and inlet/outlet housings. Common types include labyrinth, fish-scale, and carbon brush seals to prevent air leakage.

Combustion System

Provides hot air through an external furnace. It can be designed for different fuels and temperature requirements.

Principle

The rotary dryer operates based on heat exchange between hot air and wet materials.

Granules enter the rotating drum and are lifted by flights. As they fall, they contact hot air and release moisture. The drying process can be configured as co-current or counter-current flow depending on material characteristics.

Moisture evaporates continuously, and the outlet discharges dried materials with controlled final moisture content.

Application

Compound Fertilizer Production

Widely used for drying NPK granules after granulation. Ensures final moisture meets storage and transportation requirements.

Mining and Metallurgy

Used for drying ores, concentrates, and tailings with high moisture content. This is the most traditional application field.

Building Materials Industry

Applied in drying raw materials and recycled construction waste. Improves processing efficiency.

Chemical Industry

Used for drying chemical materials before or after reactions. Applicable to various industrial processes beyond fertilizers.

Environmental and Waste Treatment

Suitable for drying sludge, manure, and municipal waste. This is a rapidly growing application area.

Agriculture and Feed Processing

Suitable for drying feed materials, biomass fuels, and bulk agricultural products.

Advantage



Flexible System Design

Supports different capacities and process configurations.



Energy-Efficient Design

Optimized airflow and internal structure reduce energy consumption per ton of material.



Durable Mechanical Structure

High-strength tyres and rollers ensure long-term stable operation.



Intelligent Control System

Equipped with sensors and automation to monitor temperature and speed. Enables real-time adjustment for stable drying performance.



Strong Adaptability

Suitable for materials with different moisture content and properties. Can handle both powder and granules.



Easy Operation and Maintenance

The rotary dryer structure is simple. Maintenance mainly focuses on seals, flights, and transmission components.

Technical Specifications

Model	Diameter (mm)	Length (mm)	Capacity (t/d)	Weight (t)	Power (kW)
SYM 2520	2500	20000	300	90	30
SYM 2820	2800	20000	450	105	37
SYM 3025	3000	25000	600	120	55
SYM 3225	3200	25000	1000	135	132
SYM 3525	3500	25000	1600	175	160
SYM 4030	4000	30000	2500	230	200
SYM 4840	4800	40000	3500	450	280

Customized drum thickness and internal flight configurations are available upon request.

FAQ

1. What is the typical outlet moisture of a rotary dryer?

For compound fertilizer, the final moisture is usually reduced to 1–5%. This depends on inlet moisture, temperature, and retention time.

2. How to choose co-current or counter-current rotary dryer?

Co-current flow is ideal for heat-sensitive materials (like fertilizers) as the highest heat meets the wettest material. Counter-current flow offers higher thermal efficiency and is better for achieving extremely low moisture in general industrial minerals.

3. How to prevent material buildup inside the drum?

Optimized flight design helps control material movement. Chain cleaners or knockers can be installed, and regular cleaning is required.

4. Is rotary dryer maintenance complicated?

Maintenance is relatively simple. Regular inspection of seals, flights, rollers, and gears ensures stable operation.

Rotary Drum Dryer