Wood chips are an essential raw material in a variety of applications, including biomass pellet fuel, wood-based panel manufacturing, edible fungus cultivation, and even organic fertilizer production. However, fresh wood chips from wood processing plants typically contain as much as 35%-55% moisture, significantly limiting their application value. Wood chip dryers are key equipment for addressing this bottleneck. By efficiently removing moisture, they transform damp, perishable wood chips into a stable, high-value commodity.
1. Working Principle of Wood Chip Dryers
Currently, the most widely used type is the drum dryer, which operates as follows:
Loading: Wet wood chips are evenly and quantitatively fed into the drying drum via a belt conveyor or screw feeder.
Drying: The drum rotates slowly, driven by a motor. High-temperature hot air generated by a hot air furnace (the heat source can be biomass, natural gas, steam, etc.) fully contacts the wood chips within the drum. The inner wall of the drum is equipped with lifters that continuously lift and drop sawdust during rotation, forming a uniform curtain. This significantly increases the contact area between the sawdust and the hot air, ensuring efficient heat exchange and moisture evaporation.
Separation and Dust Removal: Exhaust gas containing moisture and fine dust exits the drum along with the dried sawdust, where it enters a cyclone separator or baghouse.
Discharge: Dry sawdust reaching the target moisture content (typically 8%-12%) is discharged from the discharge port. After cooling, it can be packaged for storage or used directly in the next production process.
2. Core Advantages of Sawdust Dryers
Efficient and Energy-Saving: Modern dryers utilize a scientific hot air circulation system and thermal insulation design, resulting in high thermal energy utilization and low unit dehydration costs.
Large Processing Capacity and Continuous Production: The industrialized design enables 24-hour continuous operation, with processing capacities ranging from hundreds of kilograms to tens of tons per hour, meeting the needs of large-scale production. Uniform and Stable Drying: Thanks to the rotating drum and the internal lifting plate, the sawdust is evenly heated, resulting in a consistent moisture content and quality in the finished product.
High Fuel Flexibility: The drying heat source is highly selectable, making it particularly suitable for use with biomass fluidized bed furnaces. Waste materials such as sawdust and wood shavings can be directly utilized as fuel, achieving "waste-to-waste" treatment and minimizing operating costs.
3. Application Areas
Dried sawdust is primarily used in:
Biomass pellet/briquette fuel production: It is the core prerequisite for producing high-calorific-value, low-impurity solid fuel.
Manufactured board industry: It is used in the production of particleboard, density board, sawdust board, etc.
Edible mushroom cultivation: It serves as a culture medium for mushrooms such as shiitake mushrooms, wood ear mushrooms, and oyster mushrooms.
Organic fertilizer production: It serves as a raw material for adjusting the carbon-nitrogen ratio and compost structure.
Livestock bedding: Dry, absorbent sawdust makes an excellent livestock bedding material.
Conclusion
The wood chip dryer solves the fundamental challenges of wood chip storage, transportation, and utilization, transforming a previously inexpensive waste product into energy, wood panels, and food. This truly achieves a win-win situation, transforming waste into treasure, recycling resources, and achieving both economic and environmental benefits.
