Letting off some steam at the Eureka Public Schools’ new biomass boiler system – Fuels for Schools

"Every day that this runs, we save $2,000," Powell pointed out.

A tall smokestack rises up between the Eureka Middle School and Elementary buildings, puffing a cloudy plume into the skies. But it’s not smoke – it’s mostly steam.

This is the by-product of Eureka Public Schools’ new biomass boiler system – and according to Warren Powell, maintenance supervisor at Eureka Public Schools, it has been working well. "We?Äôve been making steam with it since the end of November," he said. And on most days, he added, it’s been burning beautifully.

By Krista Tincher
Of the Tobacco Valley News

This he says as he and three other school employees pound and pull on a malfunctioning auger, the boiler shut down for the day. It’s a minor problem, he assures – merely a matter of a stripped bolt that allowed the auger to slip. It’ll be up and running in no time. They’ve had to work out the intricacies of the system over this, its first winter, but for the most part, things have been running smoothly. Most issues have been fuel related – figuring out how the system burns depending upon the quality of wood chip hauled in. "I’m really impressed with the engineering," Powell said. A lot of thought has gone into it, he said.

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For more information about Montana’s Fuels for Schools program, call (406) 542-4239 or visit: http://www.fuelsforschools.org

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Part of the system is essentially a conventional steam boiler – which hasn’t changed in design much in the past 200 years, says Powell. "Except now, we’re using augers to shovel (the fuel) in instead of shoveling," he added.

And that’s the part that most impresses him – the biomass-burning end of the biomass boiler system.
The biomass in question is waste wood product – logging slash, ground into chips. This same logging slash would have been piled and burned during the first bluebird days of spring, lacing the freshly sun-warmed air with the decisive sourness of smoke. Instead, it’s trucked to the chip-holding chamber of the biomass building to warm the wintertime learning of the students of the Tobacco Valley.

A large auger extends through a low slot that runs the length of one wall of the chip chamber. When the auger turns, it pulls the chips gradually through the slot and onto a conveyor belt in the adjoining boiler room. The conveyor belt feeds the chips gradually into a firebox. The chips rest on three separate sloped grates inside the firebox, falling down the slope as they burn. Fans blow beneath the grates, fanning the fire to a toasty 2000 degrees inside the box. It’s this heat that makes the steam to warm the schools. And it burns so completely, added Powell, that most of what you see spewing out the top is steam – the excess moisture from the fuel.

If the new system shuts down, the schools are kept warm by the backup boiler system – the old system – which is essentially fueled by diesel fuel, says Powell. The old system goes through 700 gallons of diesel fuel per day in 20 degree weather, just to heat the elementary and middle schools. To generate the same amount of steam, the biomass system burns four or five tons of wood chips per day at $40 a ton. The price difference in heating is enormous. As far as BTU equivalents go, said Powell, using the biomass system is the equivalent of using fuel oil at 35 cents per gallon.

"Every day that this runs, we save $2,000," Powell pointed out.

The biomass boiler system is regulated by computer – once Powell sets it, it controls how hot the fire burns, how much air and fuel feed it, and other aspects. Powell can observe the system remotely from his home via computer. And it calls him on his cell phone if there are any problems.

Maintenance of this system is more arduous – it demands up to six hours per day of Powell’s time versus his former two and a half. The firebox must also be cleaned of "clinkers" every four or five days. Clinkers, explained Powell, holding up a greenish-gray, mottled glasslike blob, are deposits of silica and any minerals and metals left in needles and bark. In environments of over 1,800 degrees, he said, the minerals and metals vaporize and form deposits.

At this time, the wood chips for the system are shipped all the way from the Flathead via John Jump Trucking. In the future, however, Powell hopes to see the chips obtained more locally. The Forest Service, he said, is conducting a pilot project in the Pinkham area, grinding waste wood into usable chips on site. In order for this system to be as environmentally friendly as possible, said Powell, they want to use fuel from within a 50 mile radius of the school. This summer, they will be seeking fuel utilization grants to obtain a chipper locally, he said. "The odds of us getting it are very small," Powell added, "It is something we are looking into."

As it is, the school is no longer putting diesel fumes into the air, and is instead burning what would have been burned anyway – but cleanly and efficiently. "It’s going to be a huge benefit to the school and the community," Powell said.

http://www.tobaccovalleynews.com/news.html

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For more information about Montana’s Fuels for Schools program, call (406) 542-4239 or visit: http://www.fuelsforschools.org

University of Montana-Western Campus Breaks Ground on Biomass Heating System http://www.matr.net/article-19085.html

Eureka School district to pursue biomass power generation. Receives $400K from Forest Service as first step http://www.matr.net/article-18735.html

Banking on biomass. Western Woodfuels of Whitefish, Montana http://www.matr.net/article-18593.html

Fuels for Schools Construction Grant RFP. Is your school ready to benefit? http://www.matr.net/article-17914.html