Copper Tube–Fin Heat Exchangers for Wood Chip Drying Applications

Copper tube–fin heat exchangers are widely used in wood chip drying systems due to their high thermal efficiency, robust construction, and suitability for continuous industrial operation. The unit shown in the image is a large-capacity finned-tube heat exchanger, designed for hot air heating in biomass and wood processing plants.

Application Overview: Wood Chip Drying

Wood chip drying is a critical process in:

• Biomass power plants

• Pellet production lines

• Pulp and paper mills

• MDF, OSB, and particleboard manufacturing

The objective is to reduce moisture content in wood chips to improve combustion efficiency, storage stability, and downstream processing performance.

Working Principle

In a wood chip dryer, the copper tube–fin heat exchanger functions as an air heater:

1. Hot fluid (hot water, thermal oil, or steam) flows through the copper tubes

2. Heat is transferred through the tube walls to aluminum fins

3. Process air passes across the finned surface

4. Heated air is supplied to the drying chamber, evaporating moisture from wood chips

The large fin surface area significantly enhances heat transfer efficiency.

Key Features of Copper Tube–Fin Heat Exchangers

High Heat Transfer Efficiency

• Copper tubes provide excellent thermal conductivity

• Aluminum fins increase effective heat exchange surface area

• Optimized fin spacing ensures uniform airflow and minimal pressure drop

Robust Industrial Design

• Heavy-duty frame construction for large air volumes

• Suitable for continuous operation in dusty and high-temperature environments

• Mechanical expansion or brazed tube-to-fin bonding for durability

Large Capacity Air Heating

• Designed for high airflow rates required in rotary drum dryers, belt dryers, or flash dryers

• Modular coil construction allows customization for different drying capacities

Corrosion Resistance

• Copper and aluminum materials offer good resistance to moisture from wet wood chips

• Optional coatings available for aggressive or high-humidity environments

Typical Operating Conditions

• Heating medium: hot water, steam, or thermal oil

• Air temperature range: ambient to high-temperature drying air

• Continuous airflow with particulate-laden air

Advantages in Wood Chip Drying Systems

• Faster moisture removal

• Improved energy efficiency

• Stable drying temperature control

• Reduced fuel consumption in biomass systems

• Long service life with low maintenance requirements

Common System Integration

Copper tube–fin heat exchangers are commonly integrated with:

• Biomass boilers

• Waste heat recovery systems

• Industrial fans and air ducts

• Automated temperature and airflow control systems

Customization Options

• Tube diameter and circuit design

• Fin pitch and thickness

• Coil dimensions and number of rows

• Frame material (galvanized steel, stainless steel)

• Optional anti-corrosion or hydrophobic fin coatings