Case study: Pellet boiler for factory heating

Metaltek Laser factory in Bécancour, QC

Factory heating project with a pellet boiler.

Customer: Metaltek Laser, metal cutting service.
Location: Bécancour, QC.
Engineering: Gobeil Dion & Associés inc.
Plumbing works: Plomberie CRT Therrien inc.
Electrical works: Les installations Électriques D.G. inc.

Equipment: 400kW (1,365,000 BTU/hr) Säätötuli pellet boiler.
Silo: pellet silo manufactured by the customer.

400kW pellet boiler heating the factory

Fuel: torrefied pellets.
Fuel producer: Airex Énergie inc.
The torrefied pellets are produced just 10 kilometers away from the pellet boiler. This is really local energy.

Biochar pellets made with torrefied wood

The torrefied pellets have a bigger energy content than classic wood pellets. They are also weather resistant and therefore easier to store.
It is a fuel that was developed to replace coal by a clean renewable fuel in huge coal-fired boilers. Its combustion however differs quite a lot from the classic wood pellets, and it will not work in all pellet boilers.

Säätötuli bioburners can burn woodpellets and torrefied biochar pellets

Säätötuli’s pellet boiler is equipped with Säätötuli’s multi-fuel bioburner. It can use torrefied pellets as well as wood pellets. The only requirement is to change some settings in the control automation depending on the fuel. The bioburner is even able to use agro-pellets and peat pellets, giving this pellet boiler increased versatility. When using pellets with extra-high ash content, the bioburner can be equipped with a flue gas recirculation to mitigate clinker formation during the combustion.

Torrefied pellets burn clean in Säätötuli's pellet boiler systems

Once the right automation set-up in place, the combustion of the torrefied pellet is perfectly clean. No visible smoke nor smells are emitted at the stack.

A hydronic heat loop distributes the heat in the building

The pellet boiler heats water. The hot water will then circulate in a hydronic system made with insulated pipes and heat exchangers. The heat exchangers will generate hot air that will be pushed in the region of the building that the heat exchanger is installed in. Every heat exchanger has its own thermostat. Therefore, the temperature inside the building can be fine tuned to the customer’s needs.

The C210 automation controls the operation of the pellet boiler

The C210 control automation supervises the boiler. A color touch-screen PLC with an intuitive software makes it easy to check the status of the pellet boiler and to change parameters if needed. This version of the C210 can modulate the output of the pellet boiler in a range from 20% to 100%.

Automatic ash removal augers

Ashes are automatically transferred from the fire chamber outside of the factory with conveying augers.

The mixing loop ensures a longer lifetime for the pellet boiler

The boiler mixing pump ensures a long lifetime for the pellet boiler. The mixing pump is the smaller pump on the picture above. It automatically mixes some hot water to the inlet if the return water from the heat loop is too cold. In Finland, boilers built at the beginning of the company in 1985 are still working today as they were equipped with a mixing loop from the beginning.

You can find more information on how that works in our wiki: how do biomass boilers work.

The boiler is fed by a pellet silo that was made by the customer