High-Cleanliness Direct Coal-Fired Hot Air Furnace — India

High-Cleanliness Direct Coal-Fired Hot Air Furnace Project in India

Meibao supplied a high-cleanliness direct coal-fired hot air furnace for an industrial project in India.

 

The furnace integrates coal feeding, chain-grate combustion, secondary combustion, high-temperature gas purification, cold-air mixing and temperature control. The system converts coal combustion heat into adjustable process hot air for connection to downstream industrial drying equipment.

Raw coal is transferred to the coal hopper and continuously fed into the combustion chamber by the chain grate. The high-temperature gas generated during combustion leaves the primary combustion chamber and enters the purification chamber.

Inside the purification chamber, the combustible components in the gas undergo secondary combustion. Dust carried by the combustion gas agglomerates and settles during the high-temperature purification process.

The purified hot air leaves the purification section at approximately 900°C. A controlled quantity of cold air is introduced in the mixing chamber to produce process hot air between 100°C and 900°C.

The adjusted hot air is then delivered to the connected drying equipment through the hot-air duct system.

Raw Coal
→ Coal Feeding System
→ Coal Hopper
→ Chain-Grate Feeding
→ Primary Combustion Chamber
→ High-Temperature Gas Outlet
→ Secondary Combustion and Purification Chamber
→ Dust Agglomeration and Settlement
→ Approximately 900°C Purified Hot Air
→ Controlled Cold-Air Mixing
→ 100–900°C Process Hot Air
→ Downstream Drying Equipment

1. Coal Feeding

Raw coal is transferred to the coal hopper through the coal-loading system. The feeding arrangement maintains the required fuel supply for the combustion process.

2. Chain-Grate Combustion

The chain grate moves the coal uniformly into the combustion chamber. The combustion rate is coordinated with the required heat output and hot-air conditions.

3. Primary Combustion

Coal burns in the primary combustion chamber and generates high-temperature combustion gas. The gas leaves the combustion chamber and flows into the purification section.

4. Secondary Combustion

The high-temperature gas undergoes a further combustion stage inside the purification chamber. This process supports more complete combustion before the gas enters the hot-air mixing section.

5. High-Temperature Purification

A small quantity of dust carried by the combustion gas agglomerates and settles inside the purification chamber. The combination of secondary combustion and settling purification improves the cleanliness of the process hot air.

6. Cold-Air Mixing and Temperature Adjustment

The hot air discharged from the purification chamber is approximately 900°C. Controlled cold air is introduced into the mixing chamber to adjust the final hot-air temperature.

The system supplies process hot air within a range of 100–900°C, with continuous temperature stability of ±5°C.

7. Hot-Air Delivery

The adjusted hot air is transferred through the duct system to the connected drying equipment. The temperature and heat supply are controlled according to the production process.

• Coal-loading system
• Coal hopper
• Coal-feeding mechanism
• Chain grate
• Primary combustion chamber
• Secondary combustion chamber
• High-temperature purification chamber
• Dust-settling section
• Cold-air inlet and regulating system
• Hot-air mixing chamber
• Air-supply and draft system
• Hot-air outlet and ductwork
• Temperature monitoring system
• Electrical control cabinet
• Inspection platform and supporting structure

Direct-Fired Heat Utilization

After secondary combustion and purification, the high-temperature gas is used directly as process hot air. The system does not rely on an intermediate heat exchanger.

Adjustable Hot-Air Temperature

The cold-air mixing system adjusts the process hot air between 100°C and 900°C.

Temperature Stability

The continuous hot-air supply is controlled with a temperature stability of ±5°C.

Thermal Efficiency

The furnace is designed with a thermal efficiency above 95%.

Combustion and Purification Integration

Primary combustion, secondary combustion, high-temperature purification and air mixing are integrated into one furnace system.

The direct coal-fired hot air furnace series can be connected to:

• Spray-drying towers
• Industrial drying chambers
• Fluidized-bed dryers
• Calcining equipment
• Other hot-air drying systems

It is used in industries including:

• Detergent and daily chemical production
• Ceramics
• Fertilizer
• Chemical processing
• Feed production
• Rubber drying
• Building materials

The direct coal-fired hot air furnace series incorporates multiple patented technologies. Its development received support from the Technology Innovation Fund for Small and Medium-sized Enterprises under China’s Ministry of Science and Technology.

The furnace structure combines combustion, purification and hot-air temperature adjustment to provide process heat for different industrial drying systems.

 

 

 

 

The India project supplied an integrated furnace system covering:

• Coal feeding
• Chain-grate combustion
• Primary and secondary combustion
• High-temperature purification
• Cold-air mixing
• Hot-air temperature adjustment
• Process monitoring and control
• Connection with downstream drying equipment

Meibao provides integrated industrial heating services covering:

• Heating-process design
• Fuel and combustion-system configuration
• Furnace engineering
• Equipment manufacturing
• Hot-air duct-system design
• Electrical and temperature control
• Installation guidance
• Commissioning support
• Operator training
• Overseas technical service

Contact Us

Planning an industrial drying or process-heating project?

Send us your required hot-air temperature, air volume, heat demand, fuel information, material characteristics, drying equipment and site conditions. Meibao will prepare the corresponding furnace and hot-air system configuration.

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