Belmont man believes he's created much more efficient means of capturing heat in wood

Published Date Written by Adam Drapcho

BELMONT — Butch Walrath is a man given to tinkering. Recently retired from a career as a maintenance technician at the state prison in Concord, he is also an amateur radio practitioner, a journeyman machinist, a welder, and is licensed to work on oil and gas burners. For the past 17 years, he's been chewing on a concept that would revolutionize the home heating and energy production industry, and he thinks he's perfected it.
Walrath's invention is a gasifier burner, something he thinks will consume wood, wood pellets, anything made of carbon, actually, and burn it much more efficiently, and cleaner, too, than any other stove on the market. He has a provisional patent in hand and is working with state officials to have his burner examined by experts and academics.
"I do this as a hobby, a real concerned hobby," said Walrath. He started working with gasifier burners 17 years ago, initially attempting to use them as a way to capture hydrogen or other combustible gasses to be collected and used as fuel for internal combustion engines, such as a generator. Walrath is far from the first to employ the concept. During World War II, gasifier burners were employed to create fuel when gasoline was rationed or unavailable.
Walrath, though, became uncomfortable with the idea of keeping a large tank full of hydrogen gas on his property. So, he modified his concept. Instead of diverting the hydrogen and other gases into a holding tank, he's developed a stove that redirects the gases — along with the smoke and tars — back into the combustion chamber, where they are converted into flame. The result is a combustion of wood which results in no smoke, no tars, just a lot of heat and carbon monoxide, and a very small amount of ash.
By Walrath's analysis, which is based on observations of ash left behind and the smoke — or lack thereof — produced by his burners, they extract nearly 100 percent of the energy contained within the pellets. Conventional wood or pellet stoves, he said, are lucky to convert 60 percent of the available energy in wood into heat.
Walrath's burners are steel containers with hollow walls and a wire grate floor to hold the pellets or wood. The walls of the structure have holes drilled on the bottom of the outside layer, to allow fresh air to enter. They also have vent holes on the interior walls, both at the top and bottom of the combustion chamber. Once the burn cycle is underway, smoke and hot gases released by the burning fuel is sucked downward, through the grate floor, and drawn up through the hollow walls, to the top vent holes where they are blown out over the combusting wood. Those hot gases then combust above the fuel, depriving the wood of oxygen and converting it to charcoal as it burns.
No smoke or odor escapes unburned from the combustion. When the burn is complete, what is left behind is dramatically less ash than what would have been created by burning the same amount of pellets in a conventional pellet stove, said Walrath.
Speaking of pellets, Walrath has turned his eye to the fuel for his burners. He's acquired the equipment necessary to produce his own pellets, and has settled on a recipe of 40 percent hardwood, 40 percent softwood and 20 percent household trash. Because the gasifier cycle will consume nearly anything, with the exception of petrochemicals, he said, and because the burn eliminates any concern about smoke or odor, he sees no reason why garbage should be buried in landfills when it could be used to heat homes or generate electricity.
For now, Walrath sees three applications for his burners. One is designed to replace the common campfire. It produces heat and flames, great for hot dogs and such, but without the swirling, noxious smoke that pesters those who sit around it. Another of his burners could be modified to sit within a pellet stove, allowing homes to be heated with significantly less pellet fuel thanks to a more complete burn. Finally, he thinks his burner design could make biomass electricity production a compelling and cleaner competitor to coal, especially considering the addition of garbage to the wood fuel.
"We have acres, acres all over, of garbage pits. Let's go into those pits and mine the crap back out," he said.
If he can get the right eyes to give his burners a fair analysis, Walrath insists the idea that spent 17 years gestating in his workshop will change the way the world looks at heat and energy. "This is what's going to be used in the future, believe me."

CAPTION for GASIFIER BURNER in AA:
Butch Walrath, shown here in his Belmont workshop, demonstrates the combustion cycle of his prototype burners. He thinks his burners will change the way homes are heated and electricity is generated. (Laconia Daily Sun photo/Adam Drapcho)