1. What Is a Sinter Ring Cooler?

A sinter ring cooler, also known as a circular cooler for sinter, is a key piece of equipment in the iron ore sintering process. It is used to cool hot sinter discharged from the sintering machine before downstream handling, screening, and transportation.

In a typical sinter plant, hot sinter at temperatures of approximately 600–800°C is transferred to the ring cooler, where ambient air is drawn through the sinter bed to reduce its temperature to a level suitable for further processing or charging into the blast furnace system.

Because of its annular structure and continuous operation, the sinter ring cooler is widely adopted in medium and large-scale steel plants.

2. Working Principle of a Sinter Ring Cooler

The sinter ring cooler operates on a forced air cooling principle:

1. Hot sinter is evenly distributed onto the annular cooler bed.

2. Cooling air is drawn upward (or downward, depending on design) through the sinter layer.

3. Heat is transferred from the hot sinter to the cooling air.

4. Cooled sinter is discharged continuously, while hot exhaust gas is collected through hoods and ducting.

This process ensures:

• Stable cooling performance

• Continuous material flow

• High operational reliability

The circular layout allows uniform residence time and effective temperature control across the entire cooling zone.

3. Role of the Sinter Ring Cooler in the Sintering Process

Within the overall iron ore sintering system, the ring cooler serves several critical functions:

• Thermal conditioning of sinter prior to screening

• Mechanical stabilization, reducing breakage during handling

• Preparation for blast furnace charging

• Heat source for waste heat recovery systems

Without adequate cooling, hot sinter can damage conveying equipment and negatively affect downstream processes.

4. Exhaust Gas Characteristics of a Sinter Ring Cooler

From an environmental and energy perspective, sinter ring cooler exhaust gas is of particular importance.

Typical characteristics include:

• Medium-temperature flue gas

• Large volumetric flow rate

• Presence of dust and fine particulates

• Trace VOCs and odorous compounds (depending on raw materials)

Because of these features, ring cooler off-gas is often treated as:

• A waste heat recovery opportunity

• A key emission source in sinter plants requiring gas treatment systems

5. Waste Heat Recovery from Sinter Ring Coolers

Modern sinter plants increasingly integrate waste heat recovery systems with sinter ring coolers.

Recovered heat can be used for:

• Steam generation

• Hot water production

• Preheating combustion air or process gas

• Supporting downstream environmental treatment units

Efficient utilization of sinter cooler waste heat contributes significantly to:

• Energy efficiency improvement

• Carbon emission reduction

• Overall plant operating cost reduction

6. Environmental Control and Emission Treatment

Due to tightening environmental regulations, waste gas from sinter ring coolers is commonly routed to dedicated treatment systems, such as:

• Dust removal units

• VOC treatment systems

• Thermal oxidation or catalytic processes

• Integrated exhaust gas management solutions

Proper design of the sinter ring cooler exhaust gas collection system is essential for ensuring compliance with environmental standards while maintaining stable plant operation.

7. Conclusion

The sinter ring cooler is an indispensable component of the iron ore sintering process. Beyond its primary cooling function, it plays a vital role in energy recovery and environmental management within modern steel plants.

With increasing emphasis on energy efficiency and emission control, sinter ring coolers are no longer just cooling devices, but also important nodes in integrated waste heat and exhaust gas treatment systems.