Application of Wood Chip Indirect Hot Air Furnace in Calcium Carbonate Industry

I. Project Background

In the calcium carbonate industry, especially in the powder drying process, there is a high requirement for heat sources. Typically, clean hot air at around 350°C is needed for drying.

As calcium carbonate is a white powder material, it requires extremely high air cleanliness. Any dust or impurities in the hot air may affect product quality or even lead to rejection. Therefore, achieving both high temperature and clean heating is critical.

II. Solution

To meet these requirements, an indirect biomass wood chip hot air furnace is adopted.

The system operates as follows:

• Wood chips are combusted in the furnace to generate high-temperature flue gas
• The flue gas enters the heat exchange system
• Cold air is heated indirectly through the heat exchanger
• Clean hot air (around 350°C) is delivered to the drying process

Since the hot air and flue gas are completely separated, clean air output is guaranteed.

III. Advantages

1. Clean Hot Air Output
Indirect heating ensures no contamination, ideal for white powder materials.

2. Stable Temperature Supply
Consistent hot air at around 350°C meets industrial drying needs.

3. Lower Fuel Cost
Biomass fuel significantly reduces operating costs compared to natural gas.

4. Automated Operation
Automatic feeding and temperature control reduce labor requirements.

5. Energy-saving and Eco-friendly
Supports low-carbon production and environmental compliance.

IV. Project Results

After implementation, the client reported:

• Stable drying performance and improved product quality
• Clean hot air with no contamination
• Significant energy cost reduction (20%–40% vs. natural gas)
• Reliable operation with low maintenance

This solution has become an ideal alternative to gas-fired hot air furnaces in the calcium carbonate industry.