New Life for Old Kilns

- Advertisement -

Roseburg, one of the largest capacity sawmills in the US, uses USNR for major kiln retrofit project.


USNR was recently supplier for a major kiln retrofit project for Roseburg of Dillard, Oregon. This project was what Roseburg was banking on to increase drying capacity and capitalize on a burgeoning market for its kiln dried products. At the same time it implemented kiln technology improvements that are positively impacting its efficiency and the quality of its output.

Roseburg is one of the largest capacity sawmills in the United States. The company has a rich heritage that dates back to the 1930s and the time of the Great Depression. It was founded by Kenneth Ford and today remains a closely held, family-owned enterprise. The company started out as a sawmill, and later added plywood manufacturing to the mix. Today the Dillard complex comprises a sawmill, kilns, planer mill, plywood plant, particle board plant, and cogeneration power house. The company also has operations in Montana, California, Louisiana and Mississippi. It is among the greatest exporters of wood chips, and boasts one of the nation’s largest engineered wood products manufacturing facilities.

Jeff Thompson is general manager of the operation. He relates that the sawmill is primarily a stud mill, and also produces landscape timbers. Products are marketed domestically. Most of the logs processed are Douglas fir, with some hemlock and white fir also included.

- Advertisement -

The sawmill operates on 3 shifts, processing roughly 400mbf annually. The mill was drying 70-75% of its production and selling the rest green, but it wanted to increase the dry output to improve margins and to respond to opportunities in the market.


Scoping the Project

For this project, Roseburg chose 8 of its kilns to be re-roofed; 6 double track kilns and 2 single tracks. Four of the kilns were part of the original millsite (early 1940s vintage) and the other 4 were added in the 1960s.

Jeff commented, “The decision to upgrade the kilns was really driven by the market. With where we thought it was headed, we decided to invest to capture more of the dry stud market. That sector is expanding, and we get a premium on dry stud products.”

The project comprised re-roofing 8 kilns, upgrading Kiln Boss to control those 8, and adding SCS moisture sensing. At the same time Roseburg undertook a steam conversion to increase capacity from 10 to 50 lb. extraction. The steam conversion served to increase the heat applied to the process, and decrease the drying time.


Phasing Delivery

The re-roof project was done in phases, with 2 roofs delivered at a time to allow continuous production and not overwhelm the lumber storage area. Jeff commented, “Our biggest challenge was downtime, and USNR really helped us with that by staging the delivery. We took 2 kilns down (functionally), tore the roofs apart and re-roofed while we were able to keep the other 6 functional.” He went on, “Safety was of utmost concern, but we were able to do the whole project without losing any production in the sawmill or planer.”

From USNR’s perspective the biggest challenge was determining how the old roof was constructed and supported as no drawings of the old roof could be found. As well, coordination and timing of roof delivery and installation was critical to maintaining Roseburg’s production targets. Overall the project took about 4 months to complete.


Precise Control with Kiln Boss and SCS Moisture Sensing

All 8 kilns are operated via Kiln Boss controls integrated with the SCS in-kiln moisture sensing system, to advance the drying schedule automatically from fiber saturation point (typically 25% to 27% moisture content) down to the equalization or conditioning step. Then it is designed to shut off the kiln once the average moisture content target is reached; the system is proven to within 1% moisture content accuracy.

These 8 kilns were already using the Kiln Boss system, and with the project it was upgraded to the latest version release. The SCS in-kiln moisture sensing system was new to Roseburg.


Improved Process

Jeff compared the old process with the new one. “In the past when the kiln cycle reached a stage where the operators thought it was done, they would shut the kiln down and open the doors allowing it to partially cool, and then test the wood with a hand meter. If it wasn’t quite done they had to shut the doors, heat the kiln back up and dry for additional time. Each time we lost a huge amount of energy. Now with the in-kiln moisture meters, the sensors tell us when the load is done. The kilns run a complete cycle without interruption; no wasted time and no wasted energy. They automatically shut down when the target moisture content is achieved.”

He continued, commenting on training of new kiln personnel. “We now have 3 different brands of control systems on our kilns, and USNR’s is by far the most user-friendly and easiest to learn. That is where we first focus training our new people because it is very intuitive, and the in-kiln moisture meters take out the guesswork.”


Responding to the Market

Jeff is well satisfied with the results of this project. “We were hoping to increase our percentage of dry output from 70% up to 85%, and we are currently exceeding that. With the in-kiln moisture sensing system integrated with Kiln Boss we are seeing an overall increase in the quality of the lumber.” He is also pleased he decided to go this route instead of replacing the kilns. He said he did consider other vendors, but was most familiar with USNR and Coe drying systems. “We knew USNR was a pretty safe bet.”

Jeff gives credit to Marshall Ledbetter, dry kiln supervisor, and Lee Weaver, lead pipefitter, for making the project a success. USNR’s Steve Edmonds handled the Kiln Boss controls upgrade, working with Scott Schneider for the SCS in-kiln moisture sensing system.

This project is proof positive that sometimes the smartest investment can be to retool older systems with new technology to bring them up to today’s standards. Not only can it reduce downtime and greatly extend the life of valuable assets, it can allow mills to remain competitive for the longer term. Every situation comes with its own challenges, and USNR is pleased to work with its customers to achieve a successful outcome every time.