Years ago, drying wood for use in construction, furniture, and even firewood took months or even years. Now, thanks to the kiln-drying process and advancements in technology, sawmills can achieve the optimal moisture content necessary for specific uses of wood in as little as a few days. Nevertheless, drying lumber is a tedious task that requires accuracy, attention to detail and careful application.
Accelerating a natural process demands high precision given the complexity of manipulating variables. A well-done application will require the measurement of relative humidity and airflow to control the rate at which the surface of the wood releases moisture. In parallel, there must be precise temperatures to accelerate the diffusion process of pulling moisture from the center of the wood to its surface. These variables must all be controlled simultaneously and in cooperation to ensure a high-quality product that achieves the desired moisture content.
When done correctly, lumber will achieve an on-target moisture percentage, giving sawmills a higher-quality yield and therefore higher marginal revenue. Inaccurate controls, however, can cause the quality of the board to suffer. When air circulation is too slow, the drying rate is slower than necessary, and mould could develop on the surface of lumber. On the other hand, if air circulation is too fast, surface checking and other drying defects can develop. In terms of humidity, if it is too low in the early stages of drying, it can lead to excessive shrinking, resulting in surface and end checking. Outside of quality, poor control of variables can lead to incorrect specified-moisture content, the level of dryness necessary for a particular use of wood.
Greater Control Inside Your Kiln
A simple and cost-effective improvement that can have a significant impact is the introduction of automated humidity sensors. E+E Elektronik’s high-end humidity and temperature sensor with smart relay, which allows for remote control of the electrical circuit (EE-310,) was purposefully designed for industrial uses such as in sawmills and kiln-drying environments. This sensor accurately measures humidity, and the smart relay can adjust the temperature as needed, just as an operator doing manual checks would. The ability to withstand up to 180°C (365°F) paired with its proprietary corrosion-resistant coating makes it the most advanced and effective sensor for kiln-drying applications.
In addition to lumber with fewer defects due to weather, installation of sensors boasts long-term financial gains. For example: A sawmill scraps 250 thousand board feet. The current price of lumber is $380.90 per thousand board feet, as it was recently, and the sawmill’s gross margin is estimated at 50 per cent. This results in a whopping $47,612.50 loss.
Incorporating sensors can reduce scrap by as much as 80 per cent for a savings of more than $38,000 using the above example. Furthermore, sawmills can realize considerable labour cost savings due to the automation of data collection and can shift those labour resources to focus on increasing production.
White Paper Explores Automation Using Sensors
In E+E Elektronik’s latest white paper, “Automating Simple Tasks Using Sensors,” we calculate how the cost of the sensor investment can be recuperated within one month, when accounting for staff turnover and the savings from a lower scrapping rate. For those sawmills that already have sensors implemented into their drying process, they can still reap financial rewards from upgrading their sensors to ones with higher accuracy and durability.
When choosing a sensor, it’s important to consider long-term stability, accurate measurements in a harsh environment, robustness, high resistance against pollutants, and the opportunity for easy, periodic maintenance and calibration.
For more information about E+E Elektronik sensors and technology, check out our website at epluse.com
Matthew Nemeth is Managing Director in the U.S. for E + E Elektronik, an Austrian-based Internet-of-Things technology company that develops and manufactures sensors, transmitters, hand-helds and data loggers for air velocity, CO2, relative humidity, dew point, flow, moisture in oil, pressure and temperature. E+E operates a nationally accredited calibration lab and is appointed to maintain the National Standard for Humidity and Air Flow Speed in Austria.
E+E Elektronik, USA 847-495-7744 email@example.com