Types of end user
There are several principal categories of woodfuel end user and associated needs, and woodfuel burning appliances vary in scale and complexity to suit their desired purpose. Woodfuel may be used for small scale heating, for larger scale electricity generation, or for combined heat and power (CHP) plants. Examples of the wide range of woodfuel burning systems, from small domestic units to community and district heating, are described here, together with an outline of fuel feed methods.
Domestic sized systems
- Traditional appliances that use logs: box stove, tiled stove, cooker/boiler
- Freestanding boilers – log fired using prepared logs include variants such as: multi-fuel boilers, combination boilers and wood pre-burners
- Freestanding boilers – fired by wood chips.
Domestic to medium sized systems using reconstituted fuels
These systems use quality grade extruded pellets or lower grade rolled pellets.
District heating system
This system uses wood chips or shredded woodfuel.
Commercial scale boiler units
These are usually built to a unique specification and may use a variety of burner grate types and fuel feed mechanisms.
Fuel feed methods
All wood burning systems are fed by one of the following methods:
- Auger feed
- Ram feed
- Pneumatic feed
- Rotary feed
- Spreader stroke
- By hand.