The new kiln is configured to use steam energy now, with the ability to switch over to a direct-fired process in the future.
USNR has installed many Counter-Flow Kilns since the launch of the first unit in 2005. The vast majority are direct-fired using waste wood for energy, but engineers at USNR’s Jacksonville, Florida division were happy to work with Canfor Southern Pine’s Conway, SC operation to design a kiln that would meet its needs. The new kiln is configured to use steam energy now, with the ability to switch over to a direct-fired process in the future.
Sometimes the road to success isn’t straight forward. Canfor Southern Pine at Conway, SC had been upgrading its sawmill process to increase production to take advantage of the recent upturn in markets, and needed to increase its drying capacity. But plans were hampered by a lengthy permitting process to change its dry kiln heat source. And considering that its existing steam-fired boiler was already at capacity, the new kiln had to be super-efficient. After extensive investigation Canfor selected USNR’s Counter-Flow Kiln with Kiln Boss controls. The system is currently using the mill’s existing steam heat, with immediate gains in efficiency and lumber quality. With a future conversion to a direct-fired process, it will reach its desired destination.
The Conway site includes a sawmill, dry kilns, planer mill and treating plant. The operation produces dimension lumber (2×4 through 2×12), 5/4 x 6 radius edge decking, 4×4 timbers, and boards. The mill currently runs two shifts with an annual capacity of 175 mmbf.
With five conventional steam kilns the mill was still facing a lumber drying bottleneck and needed to increase drying capacity. The decision was made to construct a sixth kiln. Tim Papa, manager at the Conway site explained the challenge, “Our boiler was producing as much steam as it was capable of producing so we had to have an energy efficiency improvement with the steam we already had. For that reason we went with a continuous flow design.”
Tim added, “With all the capital improvements we’d done in the mill it was performing past its drying capacity, so this addition was the next logical step.”
He continued, “Part of the reason for going with a steam-fired kiln was the easier permitting process. Long term we plan to convert it to a direct-fired unit. In fact it already has some of the duct work and design to make the transition a lot easier in the future.”
Best Value for Investment
Travis McDonald, chief engineer for the company, works out of the head office at Myrtle Beach, SC. He commented that this is the first continuous flow kiln for the Canfor Southern Pine operations. “We went through a pretty exhaustive research process that spanned a couple of years. We visited several mill sites with continuous kilns from various manufacturers with various heating methods. Travis added, “Conway’s other five kilns are all from USNR, and we are very comfortable with the Kiln Boss software and the kiln itself. The USNR Counter-Flow Kiln gave us the best value for our investment.”
The new kiln has been operating since mid-June 2013 and Travis said he couldn’t be happier with USNR’s construction crews. “We were able to start it up about 2 weeks earlier than our project target. Getting it running was a fairly quick process.”
The next step will be to convert the new kiln to a direct-fired burner. Travis said that with markets improving, the enhanced production capacity at Conway is helping the company’s bottom line tremendously. In spite of having to convert the kiln’s energy process, it is making the Conway operation more profitable, with higher throughput and better quality lumber.