Anyone who drove along the North Road in January or February will remember the burning piles of slash beside the highway that cast a smoky pall over the area for several weeks.
The slash piles, leftover from logging along the highway to cut beetle-killed spruce, were burned to dispose of them and to kill spruce bark beetle eggs in the dead wood.
A new technology recently brought to Alaska by S & R Environmental will eliminate such open burning of slash piles in the future, along with the disagreeable masses of smoke they create.
The Air Burner incinerator, manufactured by Whitton Tech-nologies of Palm City, Fla., was fired up for a demonstration burning by S & R on Friday near a residential neighborhood off Forest Drive in Kenai. The burner was being used to dispose of slash piles left as part of Project Impact's clearing of beetle-killed spruce trees in the area.
"This unit will burn 25 tons in an hour, without any smoke or sparks," said Mike Wicker, general manager of S & R.
The burner emits a visible draft of heat into the air, but no smoke.
According to Wicker, the secret of smokeless combustion lies in the blower mounted along one side of the incinerator. The fans in this blower, spinning at 120 mph, produce more than 18,000 cubic feet per minute of air flow, which is directed through nozzles over the firebox, creating a "curtain" of high-velocity air. This continued air flow over-oxygenates the fire, keeping temperatures very high -- in excess of 2,300 degrees. Higher temperatures provide a cleaner and more complete burn, while the protective curtain created by the rotating air mass reduces emissions.
The blower also allows for a rapid cooling of the burner. Wicker said it can be cooled enough to remove the ashes in just three hours, making quick work of large piles of slash.
"These can all be gone in less than two days," he said, pointing to slash piles nearby, adding that the ashes leftover from burning are completely biodegradable and even can be used as fertilizer.
The burner is a particularly efficient means of disposing of waste wood killed by spruce beetles, Wicker said. In an ordinary fire, the beetles' eggs, laid in the dead wood, may not be completely destroyed, and many are blown away in the smoke and sparks to land elsewhere and damage more trees.
"The high temperatures and complete burn totally destroys the eggs so they can't spread," Wicker said.
Also attending the demonstration were Jason Elson, Kenai Fire Department chief, and James Baisden, Kenai fire marshal.
"It's pretty slick," Baisden said. "Right now we're not allowing open burning of slash in Kenai, but this could still be used, since it's in a closed container. It's definitely safer and cleaner and environmentally friendly."
Similar burners have been used Outside for disposal of carcasses of diseased animals and the mountains of debris left behind after hurricanes or tornadoes. The unit can be moved to any site where it is needed.
"We can take this out of Kenai, across the inlet, anywhere in the state," Wicker said. "Put it on a trailer and away it goes."
Sean Cude, vice president and part owner of S & G Environmen-tal, said the Air Burner cost $130,000, but the company plans to buy more.
"It's actually very cost effective," he said. "It doesn't take a 20-man crew to burn slash with it, and no one has to stand around and watch it to keep it from spreading."
And motorists along the highway won't have to drive through clouds of smoke for days at a time.
