Drying of wood shavings and wood chips
from shavings .
... to pellets
Industrial wood dryingFreshly cut wood has a humidity content of 40-50%. The calorific value is between 2.3 and 2.9 kWh/kg. Natural drying takes place outdoors over a period of several years, whereby the humidity content is reduced (to approx. 30%), thus increasing the calorific value to approx. 3.4 kWh/kg.
A much more effective drying method is industrial wood drying in a drying plant. The drying time and the humidity content are drastically reduced, increasing the calorific value to approx. 4.3 kWh/kg.
Process descriptionBinder manufactures professional drying plants for drying renewable raw materials. After this, the wooden chips or shavings are evenly distributed on the dryer belt via a conveyor belt and distributing unit.
The product is then conveyed on the ventilated belt through the actual drying chambers. Hot air is vertically directed through the product.
Depending on the available temperature level, the air is directed through the product once or several times. In doing so, it absorbs water from the product and cools down. The efficiency of the drying process is increased by the right selection of the drying procedure and particularly by the air guidance.
Depending on the temperature level we differentiate between low-temperature and medium-temperature drying. This frequently depends on the available heat sources. The heating of the dryer can be done according to the conditions available at the operating company with hot water, natural gas, or low-viscosity oil or even pellets or wood chips.
Utilisation of waste heatThe energy required for drying can be fully or partly provided by the waste heat from other processes (e.g. CHP). This presents apart from the direct economical advantage an additional benefit as regards power supply.
Fully-automatic control systemThe technical systems are to be used preferably in 24 hour operation. For this purpose, Binder supplies a fully-automatic control system. This enables the operation of such a plant with a minimum level of supervision.