RF Gevers opted for the low-temperature high-pressure kilns.
“I believe we are of the most advanced semi-automated sawmills in southern Africa,” remarks RF Gevers’ operations director Kelvin Bland. The commissioning of two new kilns rounds off several years of intensive research, upgrades and at times “unorthodox” refining of the mill’s logyard, wetmill drying throughput.
RF Gevers participates in the Crickmay & Associates performance benchmarking programme to monitor its progress. It received the Intermill Comparison annual Productivity Improvement Award twice and is a regular on the runners-up list, including 2021 and 2022.
Bland attributes the softwood mill’s productivity improvements to an intrinsic knowledge and understanding of sawmilling. “I have never forgotten Don Priest’s warning when I completed my saw doctor qualification in 1998: ‘A sawmill is a thousand things going wrong at the same time’. How right he was”.
Bland has a maverick attitude when it comes to the role of sawmill managers. “You can’t spend time in meetings that do not add value. I believe sawmill managers must be hands-on, receiving and analysing real-time production data and communicating with machine and maintenance services operators. A good sawmiller feels the sawmill. You cannot sit in an office all day.”
The sawmill processes a mix of Pinus elliotti and Pinus patula sawlogs into various grades of structural clears and semi-clears. The logs are sourced from seven suppliers in different locations, some up to 200km away.
RF Gevers’ increasing wetmill throughput is a direct consequence of standardised stacking of optimised boards. Each log is scanned to determine the best fibre recovery and minimum waste cutting pattern. Sensors and cameras in the wetmill track the logs as they enter the Braun and EWD framesaw and Mill Industries bandsaw lines.
The data network provides accurate information on production processes, predictive maintenance and recovery.
“Relatively small changes make substantial productivity improvements,” Bland comments. “For instance, we built and installed a 40 tonnes scissor-lift stacking system that increased production by 15%. Importantly, we did not lay off any staff despite the automation.”
A stack of dry lumber fresh from the kiln.
Increased recovery and standardised stacking shifted focus from the wetmill to inefficiencies in the drying section. It was time for a new kiln to replace a 40-year-old brick kiln with a leaking storm-damaged roof.
Bland consulted several kiln manufacturers and their local representatives before opting for the Brunner-Hildebrand HTR100 dry kilns supplied and supported by Nukor. He made the unorthodox decision to invest in the low-temperature kilns fitted with high-pressure moisture jets rather than the more “traditional” high-temperature kilns
He explains that the stack’s outer boards cool down when a high-temperature kiln is stopped during its cycle. When drying resumes, it takes a while before the climate in the kiln reaches optimal conditions, and the process increases the possibility of drying defects and recovery loss.
Two Brunner-Hildebrand HTR100 humidification kilns were installed. They have flow controls and additional booster coils that ensure efficient heating during timber drying by eliminating dead heat areas.
“The kilns are well designed and constructed, and the technical and mechanical support from Nukor and the manufacturer were excellent,” says Bland. “I am impressed by Brunner-Hildebrand’s new B-Vector controller. The software is very user-friendly, and the high-pressure moisture system lets us adjust settings mid-schedule without stopping or affecting the drying process.
“We are happy with the quality of the products exiting the kilns. Despite drying the timber at 90°C, which is 25°C lower than the drying temperature of our Windsor and Bollman kilns, the drying time is reduced from three to two and a half days, with fantastic results.”
The additional capacity increases RF Gevers’ production choices and market opportunities. The floods in KZN and Durban earlier this year affected several clients who cancelled standing orders because of stock, structural and infrastructure damage. It has taken them a while to come back on stream; however, Bland says business is back to normal.
RF Gevers has partnered with Schneider and invested in a biomass energy-generating plant. Although the sawmill is grid-tied with a backup generator on standby, it has drastically cut its energy consumption costs by using its waste to power the plant.
The next phase of the RF Gevers unrelenting productivity drive is the drymill.
Kelvin Bland is impressed with the easy to use B-Vector controller software.