Rotary Cooler

The Essential Link for Efficiently Stabilizing Hot Granules in Continuous Fertilizer Production Lines

The Rotary Cooler is a critical post-drying unit operation designed to efficiently lower the temperature of hot, dried fertilizer granules. Utilizing a rotating drum and counter-current airflow, it gently cascades material while cool ambient air is drawn through the product bed. This process stabilizes the granules, prevents caking, and prepares them for safe storage and packaging, ensuring final product quality and longevity.

Key Features

  • Counter-Current Cooling Principle

    Ambient air flows opposite to the direction of hot material travel, maximizing heat exchange efficiency and achieving a lower, more uniform final product temperature.

  • Gentle Cascading Action

    The rotating drum and internal lifting flights ensure gentle tumbling of granules, promoting uniform cooling while minimizing particle abrasion and dust generation.

  • Robust Drum Construction

    Built with heavy-duty steel plate and durable internal components to withstand abrasive materials and continuous 24/7 operation.

  • Efficient Air Handling System

    Features a high-volume induced draft fan and properly sized air inlet/outlet areas to ensure optimal airflow with minimal energy consumption.

  • Dust-Controlled Environment

    Integrated with a cyclone separator or dust collection system at the air exhaust to maintain a clean working environment and recover product fines.

Advantages

  • Prevents Product Degradation

    Rapid cooling minimizes the time granules spend at elevated temperatures, reducing the risk of moisture re-absorption, caking, and nutrient degradation.

  • Improves Handling & Storage

    Cool, stable granules are easier to convey, screen, coat, and store in bulk without the risk of thermal damage to bags or liners.

  • Enhances Process Safety

    Cools granules to a safe temperature before storage, mitigating potential fire or combustion hazards associated with hot, oxidizable materials.

  • High Capacity & Reliability

    Matches the high throughput of modern rotary dryers and granulators, offering a reliable and continuous cooling solution.

  • Low Operational Cost

    Simple mechanical design and efficient heat exchange principle result in low power consumption and minimal maintenance requirements.

Applicable Raw Materials

  • All Dried Fertilizer Granules

    NPK compounds, urea, ammonium nitrate, DAP/MAP, potassium chloride/sulfate.

  • Organic & Bio-organic Fertilizer Pellets

    Cooled after the drying process to preserve quality.

  • Soil Amendment Granules

    Such as limestone or gypsum pellets.

  • Various Industrial Granules

    Including minerals, salts, and chemical products requiring cooling after thermal processing.

Basic Structure & Components

Rotating Drum

The main cylinder, slightly inclined, fitted with internal lifting flights to cascade the material.

Air Inlet Hood (at discharge end)

Allows ambient air to be drawn into the drum, flowing counter to the material.

Air Outlet Hood & Ducting (at feed end)

Collects the warmed, moisture-laden air and channels it to the dust collection system.

Drive System

Consisting of motor, reducer, pinion gear, and girth gear for smooth drum rotation.

Support Structure

Includes riding rings, support rollers, and thrust rollers to bear the drum’s weight and maintain alignment.

Feed Chute

Channels hot material from the dryer into the cooler.

Discharge Chute

Guides cooled product out to the next process stage (e.g., screening).

Induced Draft Fan

Creates the necessary airflow through the drum.

Dust Collector (Cyclone/Bag Filter)

Cleans the exhaust air.

Base Frame & Casing

Provides structural integrity and safety enclosures.

Technical Data

Specification Shell Production Capacity Flow Direction Reducer Motor Size (LxWxH) Weight
I.D. mm L mm Slope (°) Rev r/min Model Ratio Model Power
Φ1.2×7 1200 7000 2.5 6.4 ~5 Upstream JZQ500 31.50 Y160M-6 7.5 8275x2700x3391 9.0
Φ1.2×10 1200 10000 2.5 6.4 ~6 JZQ500 31.50 Y160M-6 7.5 11275x2700x3522 10.0
Φ1.5×12 1500 12000 2.5 4.28 ~8 ZQ650 31.50 Y180L-6 15 13800x3450x3080 19.0
Φ1.6×14 1600 14000 2.5 5.5 ~10 ZQ650 23.34 Y200L1-6 18.5 17500x3550x3180 21.0
Φ1.8×14 1800 14000 2.5 5 ~12 ZQ650 23.34 Y200L1-6 18.5 14680x3460x3711 25.0
Φ2.0×16 2000 16000 2.5 3.38 ~16 ZL65 40.00 Y200L2-6 22 17580x3968x4400 38.0
Φ2.2×15 2200 15000 2.5 3.0 ~18 ZL65 40.00 Y200L2-6 37 17090x4460x5250 46.0
Φ2.4×16 2400 16000 2.5 3.17 ~24 ZL75 40.00 Y280M-6 55 17600x4100x5300 52.0
Φ2.6×24 2600 24000 2.5 3.29 ~30 ZL100 35.50 Y280M-6 55 26000x4400x7100 81.0
Φ2.8×18 2800 18000 1.8 4.1 ~35 ZL115 45.00 Y280S-6 75 16868x4280x5410 72.0
Φ3.2×25 3200 25000 2.5 2.6 ~45 ZSY450 63.00 Y315M-4 132 29500x6500x6300 138.0
Φ3.0×24 3000 24000 1.8 2.65 ~40 ZSY450 71.00 Y315M-4 132 26615x5760x6269 122.0
Φ3.4×30 3400 30000 2.0 2.5 ~50-55 ZL130 45.00 Y2-355M2-6 200 30600x6678x6540 170.0
Φ3.6×30 3600 30000 2.0 3.6 ~90 ZSY500 35.50 Y2-355L-6 250 30600x6890x6540 185.0
Φ4 .0x20 4000 20000 2.0 4.2 ~130 ZSY500 80.00 YKK4003-4 315 22800x7800x7060 192.0

Key Differentiators vs. Other Cooling Methods

Offers gentler handling for softer or more abrasive granules with less particle attrition. It is typically more robust and lower maintenance for heavy-duty fertilizer service compared to the more complex air distribution systems of fluidized beds.

Provides significantly better heat exchange efficiency due to the continuous tumbling action that exposes all granule surfaces to the cooling air. A rotary cooler generally has a smaller footprint for the same capacity and is fully enclosed for better dust control.

A dedicated cooler is far more energy-efficient than misusing a dryer with ambient air. It is purpose-built for heat removal with optimal airflow design, whereas a dryer used for cooling is thermally inefficient and can lead to moisture condensation issues.

The rotary cooler is the industry-standard, high-efficiency, and most reliable choice for continuous, high-volume cooling of fertilizer granules, seamlessly integrating with rotary dryers and granulators to form a complete processing line.