Wood Fuel Testing
New Member
The quality of wood fuel is a vital part of ensuring biomass boilers work efficiently. 2 key factors are moisture content and particle size distribution.
Moisture content (MC)
If fuel is too wet then you could be seeing smoke and creating tar caused by incomplete combustion and you’ll be using more fuel than you may expect. You’ll likely be paying for water rather than energy. If the fuel is too dry you could overheat the grate and see premature wear within the boiler.
The common method of MC determination within the wood fuel industry is to use an electrical pin meter. These do not measure the MC directly but rather they measure electrical resistance. They use internal calibration curves to determine MC based on resistance. After many, many months of testing various pin meters against the oven dry laboratory standard (EN14774-2) for MC we have concluded that these can only be used as a GUIDE to moisture. They may work well in a laboratory setting but in real life the readings just aren’t accurate, reliable or repeatable. Sadly there is no simple substitute for determining MC other than using the recognised methodologies.
Particle size distribution
As for particle size of woodchip? Some biomass boilers can be very “fussy” and need chip within a tight specification; otherwise you could be seeing some blockages in the in-feed system. It’s almost impossible to tell what specification wood chip is just from looking at it, and in order to test it specialist equipment is needed.
For more information please see www.woodfueltesting.co.uk
or call... 01623 494333
Moisture content (MC)
If fuel is too wet then you could be seeing smoke and creating tar caused by incomplete combustion and you’ll be using more fuel than you may expect. You’ll likely be paying for water rather than energy. If the fuel is too dry you could overheat the grate and see premature wear within the boiler.
The common method of MC determination within the wood fuel industry is to use an electrical pin meter. These do not measure the MC directly but rather they measure electrical resistance. They use internal calibration curves to determine MC based on resistance. After many, many months of testing various pin meters against the oven dry laboratory standard (EN14774-2) for MC we have concluded that these can only be used as a GUIDE to moisture. They may work well in a laboratory setting but in real life the readings just aren’t accurate, reliable or repeatable. Sadly there is no simple substitute for determining MC other than using the recognised methodologies.
Particle size distribution
As for particle size of woodchip? Some biomass boilers can be very “fussy” and need chip within a tight specification; otherwise you could be seeing some blockages in the in-feed system. It’s almost impossible to tell what specification wood chip is just from looking at it, and in order to test it specialist equipment is needed.
For more information please see www.woodfueltesting.co.uk
or call... 01623 494333