Energy Efficient Wood Drying: It’s All About the Sensor!
In times of rising energy costs and raw material shortages, manufacturing companies are intensifying their focus on the need to optimise the efficiency of processes. High precision, state-of-the-art sensors enable users to control and operate drying systems for wood with maximum energy efficiency. Humidity and temperature measurement devices from E+E Elektronik make this possible – and much more besides.
Wood Drying Processes: The Macroeconomic Perspective
One key factor in the general cost-effectiveness of a wood dry kiln is the quality of the process: the best and most uniform drying results are only achieved where the air distribution and air flow within the chamber are ideal. There is no doubt that wood moisture is the most important parameter as regards intelligent climate control in wood drying chambers. A drying process of this kind takes between two and 300 days, depending on the type of wood and target moisture content as well as the quality standard required. To optimise drying times, a suitably adapted drying program is selected for every type of wood, whereby the accuracy of the moisture measurement is critical. In particular, overdrying due to incorrect measurements will extend throughput times, impair product quality, waste energy and reduce dryer capacities.
Suitable sensors make it possible to regulate critical moisture parameters and draw conclusions regarding wood properties.
Sensors for Wood Drying: Challenges
Since wood drying processes are performed under fluctuating environmental conditions, which may be very harsh, demands on the sensors used are high:
- Sensor protection against degassing of resins and other chemical stresses
- Long-term stability despite harsh conditions
- Possible operating range up to 120°C
- Filter caps can be interchanged, depending on application
- Simple integration of measurement data into process control
Sensors for Wood Drying: The Solution
The HTP501 digital humidity and temperature probe is the ideal solution for use in wood drying chambers. An E+E humidity sensor tried and tested over decades offers outstanding long-term stability across a temperature range of -40 to 120°C.
- Optimum sensor protection thanks to E+E sensor coating and connection encapsulation
- Highly accurate measurements thanks to temperature compensation and configurable pressure compensation
- Simple integration into process control via Modbus RTU protocol
- Interchangeable filter caps
- Sigma 05 sensor hub compatible (can be expanded to independent sensor unit with analogue outputs and display)
“The efficiency and profitability of wood dry kilns mainly depends on the quantity of thermal energy needed to heat relatively large kiln volumes. Because of insufficient sensor technology, wood is often over-dried. Detailed investigations have established that highly accurate moisture determination in the drying process – which the HTP501 probe ensures – can significantly reduce the degree of overdrying. As well as making energy savings, this can significantly increase drying capacity and prevent loss of value.”
Karl Gusenbauer, Application Segment Manager , E+E Elektronik