Wood-drying system available soon in US
Greenstone Holdings Inc.'s Green-Dri system was developed from a biotechnological concept based on Toshio Ito's Nobel Prize-winning Bound Water Transfer Theory, according to the company. Ito, a professor at John's Hopkins University School of Medicine, discovered channels that regulate and facilitate water molecule transport through cell membranes.
Wood and its cells survive and function as a living organism after being cut and the Green-Dri system uses that natural characteristic to "sweat out" water through the channels without damaging the cells, according to the company. The system allows for lower temperatures and less energy than conventional kilns, while shortening the drying time.
The sauna-like structures have double-layer walls, ceilings and floors made out of wood. The wood construction is a key element to the process and because of a constant temperature setting, no scheduling is necessary and mixtures of different species and sizes of wood can be dried at the same time. Systems can range in size from 5 feet long, 5 feet wide and 5 feet tall, to 100 feet long, 20 feet wide and 20 feet tall, according to Sal Miwa, Greenstone CEO. Costs can be anywhere from $3,000 to more than $200,000, he added. The operating cost, however, is about 10 percent that of conventional drying kilns. "Our test unit, which has 2,000-board-feet capacity, cost only $17 for electricity cost for one month," he said. "A major part of saw mill cost and energy consumption is the drying process, so we would be saving lots of energy."
The kilns come with sliding or swinging doors and feature a small entry for inspections. A protective housing is available for use in colder regions and the system can be fit for loading via forklift or rail track. The target markets for the product are saw mills, lumber yards, and manufacturers of sporting equipment, musical instruments, furniture, cabinets and others, Miwa said.
More than 30 units have been sold in Japan so far. Japan's Imperial Housing Agency approved specified usage of wood dried by Green-Dri for the new earthquake-proof Central Cultural Center at Todaiji Temple in Nara, Miwa said. The wooden Buddhist temple, also the largest wooden building in the world, dates back to 782.