“Valmet’s Belt Dryer effectively removes water by evaporating moisture from wet biomass. The dryer’s design is modular, so its sizing is flexible. The belt dryer is designed specifically for processes used in wood processing, pelletizing and biomass plants, where material is dried and converted for energy use,” says Ari Havu, who is responsible for Valmet's wood processing product development.
The Valmet Belt Dryer is a low-temperature dryer for processing biomass such as bark, wood chips, sawdust, sugarcane waste and agricultural waste. It ensures a high degree of dryness in the final product. Energy costs remain low because the dryer utilizes the mill's waste heat.
Valmet says that due to the dryer's flexible design, it can be installed as a single- or double-layer system. In a single-layer system, the biomass passes through the dryer only once. It is used as a fuel pre-dryer in applications where the final moisture content exceeds 20 percent. In a double-layer system, the biomass passes through the dryer twice. This is suitable for applications where the final moisture content must be below 20 percent.
“The two-layer system offers several significant benefits. It reduces the total consumption of heat and electrical energy required for drying. The dryer is capable of evaporating 30 tons of water per hour, so it can be used to achieve continuous dewatering with residual moisture of less than 5 percent. Thanks to the even distribution of the material, airflow control and material recycling, the easy-to-use dryer ensures both a consistent mass flow and residual moisture,” says Ari Havu.
“The dryer’s usability is excellent. Combining multiple low-temperature heat sources allows the dryer to be flexibly connected to various processes.”
According to Valmet, several different energy sources can be used to provide sufficient heat to the dryer, such as hot water, low-pressure steam and hot flue gas recovery systems. The heat obtained from one or more sources is transferred to a hot water circuit, which in turn is used to generate hot air in the dryer. The hot water circuit can be used when the ambient temperature is always above 0 °C. When the ambient temperature is below 0 °C, an ethylene glycol or propylene glycol dilution is used.
“The dryer efficiently converts biomass into fuel, so it plays a significant role in the green transition,” says Ari Havu from Valmet.
WHAT? Valmet's Belt Dryer efficiently removes water by evaporating moisture from wet biomass, effectively converting the pulp into fuel.
WHY? A modular dryer ensures a high degree of dryness in the final product. Energy costs remain low because the dryer utilizes the factory's waste heat.
