West Fraser Is Reaping the Benefits of New Continuous Dry Kiln at Pine Mill in Florida

New Kiln for Perry Plant Is 14th West Fraser Mill in South to Get KDS Windsor CDK Technology

KDS Windsor completed the installation of this 208-foot-long Continuous Dry Kiln (CDK) system at West Fraser-Perry in September 2019. The project included a 40mm EBS dry shavings burner.
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PERRY, Florida — West Fraser has been upgrading or adding new lumber kilns from KDS Windsor featuring the relatively new continuous dry kiln technology. One of the latest projects was at the company’s pine sawmill in Perry, Florida, and production superintendent Gary Lewis couldn’t be more pleased.

West Fraser-Perry is located in a region known as the ‘Big Bend.’ West Perry is a small city about 50-plus miles southeast of Tallahassee. The West Fraser operations consist of a sawmill, planer mill, and dry kilns. The facility produces Southern Yellow Pine S4S structural dimension lumber (2×4 and 2×6) and 4×4 timbers. All production is sold kiln-dried. Lumber products are sold wholesale; the majority of the production is trucked south to customers in Florida.

The company’s operations, situated on 40 acres, include the two mill buildings and dry kilns, a maintenance shop, parts storage building, and four storage sheds. West Fraser currently employs 131 people at the site. It expects to produce 115 million board feet at Perry this year.

Gary has been working in the forest products industry since 1980 and previously worked in Georgia. He has been working at the Perry mill since 1997, so he was there when West Fraser purchased it in 2017 from Gilman Building Products.

West Fraser has made several major improvements to the plant since acquiring it. They upgraded with a Porter scanning system and optimization in the sawmill and the KDS Windsor continuous dry kiln in 2019. Several more projects are in progress: a U.S. Metal Works sawdust bin, and the MoCo stacker for the end of the green production line.

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In addition to the new KDS Windsor continuous dry kiln, which began operating around September of 2019, the company has an older batch kiln for drying lumber. Both kilns are maintained by KDS Windsor, and they are equipped with KDS Windsor’s DryTrack® in-kiln moisture measurement systems. Together, the two kilns enable the company to dry 120 million board feet of lumber annually.

Green lumber entering the KDS Windsor Continuous Dry Kiln for pre-conditioning. The KDS Windsor CDK system has a reverse flow, double track design and incorporates preheating, drying, cooling, equalizing and conditioning phases all in one extended structure.

The mill is designed and equipped to process logs up to 18 inches in diameter and smaller. “We procure timber from company plots as well as single local landowners in our area of the Big Bend and have them hauled in tree-length,” said Gary.

In the wood yard, a row crane unloads trucks and stacks the logs and places them on an infeed deck to begin processing. The logs are kicked off onto a chain and fed by a Precision Husky loader to a Newnes debarker. They are conveyed to a pair of decks to be bucked down to lengths of 8-20 feet. Two separation bins separate large diameter logs and small logs, and from there they are kicked onto a lugged infeed chain going into a Cone Machinery chip-n-saw. Before entering the chip-n-saw the log data is captured by the Porter scanning system with three sets of scanner heads, and the log is positioned with a gator chain and Porter optimization.

The Cone chip-n-saw chips four sides of the log to square it up to the optimum size based on the Porter scanners and optimizer. A gang saw box removes side boards fall onto a roll case chain and are conveyed to a Cone edger. The cant enters a vertical saw arbor with 11 saws to cut boards and timbers.

Lumber is dropped onto a landing table and is scanned by SOFTAC scanners, and a SOFTAC optimizer guides a Morris Industries trimmer.

The boards are sorted by dimension and length and dropped into 42 sling bays. The bays are released to a transfer chain and green lumber stacker. The lumber currently is manually stickered into packs for drying, but the company plans to add the MoCo stacker that will automate the process. The lumber is stored on the green yard and kiln-dried as quickly as possible.

Chips and sawdust are supplied to a nearby Georgia-Pacific pulp mill. The company uses shavings from the planer mill to fuel the kiln burners, and some is supplied to a nearby particleboard mill.

The planer mill is equipped with a single line planer from Gilbert, a Canadian manufacturer.
The continuous dry kiln was a 2019 project by KDS Windsor. “They came in and built the whole thing,” said Gary. The kiln is completely equipped by KDS Windsor.

Control station with computer monitors for KDS Windsor kiln controls interface for operator; close-up shows main control screen.

“We went with the KDS Windsor continuous dry kiln based on research that indicated we could reduce our standard moisture deviation between tiers and charges to be more consistent while increasing our overall output,” said Gary. The standard moisture deviation is how much the moisture content differs from one board compared to another, he noted.

The company’s drying target is 19 percent moisture content. “If we get above single digits and below 19 percent, that’s what we want,” said Gary. “Fifteen to 16 percent moisture content is the ideal range.”

The KDS Windsor continuous dry kiln is a 208-foot-long standard model that has a main drying chamber plus conditioning chambers on both ends to prep the lumber before drying. It can dry 300,000 board feet in 24 hours, said Gary.

The decision to choose KDS Windsor to supply the new kiln was made by another executive at West Fraser, although Gary’s input was solicited. West Fraser already had experience with KDS Windsor and its continuous dry kiln technology at other mills before deciding to add one at Perry. West Fraser has 21 mills in the South, noted Gary, and nine of them have a total of 14 KDS Windsor CDK (Continuous Dry Kiln) kilns. “I know West Fraser in general loves them or they wouldn’t have had that many built…The company has made the decision to deal with KDS Windsor because of the quality and integrity.”

Kiln Drying Systems and Components Inc., which does business as KDS Windsor and is based in Hendersonville, North Carolina, is a full service manufacturer of lumber dry kilns and wood waste burners. The company’s product lines feature leading edge technology and high quality, ruggedly built drying systems for hardwoods, firewood, and Southern pine markets and leading technology in wood burning systems for high temperature, direct-fired kilns.

The KDS Windsor CDK system has a reverse flow, double track design and incorporates preheating, drying, cooling, equalizing and conditioning phases all in one extended structure. The lumber stacks travel through the kiln in opposite directions on the two tracks. The lumber push rate is automatically controlled via DryTrack® — based on moisture content in the main drying section.

As green lumber enters the kiln, it travels into the first energy recovery section where it is preheated by exiting lumber from the central main drying section. The lumber then moves through the main section and is dried to the target moisture content. The dried lumber then moves through the second energy recovery section where it is equalized, conditioned and cooled. The lumber on the other track travels in the opposite direction, so there is always a mix of dry and wet lumber in all zones interacting together.

Green lumber is scanned by SOFTAC scanners, and a SOFTAC optimizer guides a Morris Industries trimmer.

The KDS Windsor unique design provides both dry bulb and fresh air injection wet bulb temperature control. By controlling optimum wet bulb depression (dry bulb temperature – wet bulb temperature), the lumber is dried using lower temperatures while maximizing production. This method of drying produces high quality, aesthetically pleasing kiln-dried lumber.

Dry lumber exiting the KDS Windsor CDK showing moisture-read plates and SS vertical baffle to hold in heat.

The KDS Windsor Dryspec® kiln management program integrates with its DryTrack® Echo in-kiln moisture measurement system. The KDS Windsor CDK design is capable of using combinations of time, temperature and moisture content of the lumber exiting the central main drying section to control the rate of drying — the advancement of the lumber stacks.

Each track can be controlled independently, so each one can have lumber of a different thickness.

The DryTrack® Echo system is the only field proven system that can both measure lumber moisture content and control the advancement of the lumber through the kiln, according to KDS Windsor, and is essential to maximize drying efficiency, production rate, and lumber quality. Currently, more than a dozen KDS Windsor CDKs are operating successfully using this moisture-based technology.

A patented dual return air duct system brings exiting air into the mixing chamber, where it is blended with burner and fresh air. The dual return system returns only exiting air from the kiln. The duct and damper system evens the pressure between fan directions, allowing the kiln and burner to run at optimum operating levels at all times. The dual return system provides uniform heating and maximizes burner output, resulting in the highest possible lumber quality and production.

Each energy recovery section has three sections to optimize airflow while maximizing energy recovery, equalization and conditioning in each. Section dividers consist of an aluminum and stainless steel wall, and the walls are baffled horizontally and vertically, a design feature that helps achieve low standard deviation.

Over 30 KDS Windsor continuous dry kilns are operating in the U.S. and more around the world. They use direct-fired green sawdust gasifiers, shavings burners, and natural gas heat plants as well as steam-heated, high temperature hot water systems and hot oil indirect heated technology.

(For more information about KDS Windsor or its products, visit www.kdskilns.com, call (800) 274-5456, or email ngirardi@kdskilns.com.)

Gary admitted he was uncertain about continuous dry kiln technology. “I was skeptical…when we first installed the kiln as I had never seen results as good as what was indicated by the research. I didn’t think our chances of getting to 2.0 to 2.5 percent standard moisture deviation for our entire process was possible.”

When KDS Windsor representatives told Gary the standard moisture deviation the company’s continuous dry kiln technology could achieve, “I didn’t think they were telling me the truth,” he recalled. The Perry plant was averaging 4-8 percent, so 2-2.5 percent “wasn’t realistic to me.”

“I have been very pleasantly surprised,” said Gary,” to find out not only is it possible, but we have been able to maintain that for the full year of 2020 and year to date so far in 2021.”

With the low standard moisture deviation, lumber quality is excellent. “It’s the best I’ve ever seen,” said Gary. Year-to-date, the percentage of over-dry lumber is 4.5 percent, and the percentage over the wet mark is 1.1 percent.

“I’m just being honest with you,” Gary added. “I used to run the planer mill, and I would have given anything to have lumber like that when I was running the planer mill.”

With the new technology, the KDS Windsor continuous dry kiln is also easier to operate and more dependable than the company’s legacy kiln, noted Gary. “The controls are great for alerting operators to problems such as overheating zones or malfunctioning thermocouples so that small issues can be handled timely, which keeps our operations at an optimal level.”

The control system also monitors and displays information about fuel usage and temperatures in burners and kiln zones. That type of data makes “the overall function easier and more dependable,” said Gary. Monitors also track fan performance “that let us know if amps go up or belts are loose and help us monitor and repair issues very quickly.”
“We have not had to use a lot of outside tech help once we got our system tweaked to our mill,” said Gary, “but during the set-up and any time afterward we have had all the support we needed (from KDS Windsor) to keep our system functioning at an optimal level. We were even notified of some upgrades prior to seeing issues at our mill so we could head off issues we did not even know existed.”

The COVID pandemic has brought challenges, acknowledged Gary. “The COVID pandemic has been a struggle for us, as it has with most U.S. companies,” he said. Early on the company began to monitor employees closely and provide information and personal protective equipment to keep them socially distanced and safe. “This did not keep us from having issues, but I feel it did minimize the problems at our mill.” The company did not have to shut down any production lines, although it curtailed small shifts in some areas when manpower dictated those reductions.

“The situation is much better in our mill and our area at this point, though we still are cautious with PPE, cleaning, and social distancing as a preventive measure,” said Gary.