Vitolig 300 Wood Pellet Boiler – click for more general information

Principles of Burning wood pellets for heat generation.

Function
The Vitolig 300 starts automatically as soon as heat demand is reported to the control unit.  After the pre-purge (Safety function) the ignition starts (hot air fan) and the pellet worm-drive is activated.  The burner tray is filled with pellets and the boiler starts its heat-up phase.  Vitolig 300 begins to modulate when the temperature inside the combustion chamber rises above 240°c, in modulating operation the pellet worm-drive feeds the required volume of pellets into the burner tray and the vacuum draught fan will run at a speed of between 800 and 2400 rpm.  The combustion process is completed with the removal of the ashes from the burner tray.

Vitolig 300

Steel Boiler for burning wood pellets

• The Vitolig 300 for burning wood pellets hardly differs at all in terms of convenience and control from oil or gas-fired heating systems – largely due to a combination of factors such as weather compensation, modulating output and digital control unit.
• Ideal energy utilisation through self-regulation output, therefore low flue gas temperatures and high combustion efficiency of up to 95%.
• Low space requirement through compact design (floor area:0.6m2)
• Fully automatic pellet feed and vacuum system (accessories).  The integral pellet hopper (210 litres capacity) will provide fuel for up to three to five days heating operation, subject to prevailing outside temperature.
• Hot air fan for fully automatic quite ignition
• A pulsation pellet worm-drive, a variable speed vacuum draught fan and precisely metered volumes of fuel and air for modulating operation ensure optimum matching to the prevailing heat demand.
• Digital control unit with automatic function monitoring with fault diagnostic system, heating circuit control for one/two heating circuits with mixer and DHW cylinder thermostat.
• The heating mixer obtains the temperature every 10 seconds on each circuit to ensure the efficient use of the boiler and therefore reduces the running costs by sending a signal back to the boiler, which is weather, compensated.
• With self-cleaning heating surfaces and ash removal from the burner tray for long cleaning intervals. General cleaning is required once to twice a year.

What are pellets?
Wood pellets are made from 100 percent natural wood residues.  This raw material is waste matter created by the timber processing industry in large volumes through planing or sawing.  Without binders, these find grained wood residues are compressed and palletised under high pressure, i.e. they are pressed into small cylindrical shapes.  The raw material is stored and transported in absolutely dry conditions.  Absolutely dry conditions are equally necessary for the storage by the system user.  Only these precautions can ensure perfect and efficient combustion

Sizing the storage area
The storage area should be more rectangular than square and should be of a size, which allows an annual quantity of fuel to be stored.  The size of the storage room depends on the heat demand of the building.  The storage volume in m3 (incl. Empty space) is calculated by multiplying the required heat output (in kW) by a factor of 0.9 (m3/kW)  Example: A detached house with a heat demand of 15kW required a storage volume of approx 13.5m3 incl. Empty space (this corresponds to a room of 2x3 meters floor area and a usable height of 2.25m)

Storage room characteristics and fuel feed with all necessary components

• The pellet storage area must be dry, as pellets will substantially swell up if subjected to moisture.  This leads to great difficulties (e.g. blockages at the suction wand)
• The pellets storage area must be constructed as a solid leak proof structure since blowing pellets in this room will create dust and blowing pellets against the walls creates high pressure.
• Surrounding walls and ceiling must conform to fire resistance requirements.
• Doors of access hatches into the pellet storage area must open outwards and must be sealed.  Ensure the doors or hatches are constructed as fire doors
• The pellet storage area should not contain any electrical installations.  Essential electrical installation must be of the explosion proof type in accordance with current regulations.
• Avoid the installation of water pipes inside thee storage area because of the condensation and the risk of burst pipes.
• The Pellet storage area must be free from debris (small stones, wood particles, etc)
• Distribute the suctions wands so that the storage area is efficiently emptied.

 
Delivery Forms
Currently, wood pellets are offered in 15 and 30 kg sacks in bulk up to 1000 kg on pallets and loose.  Pellets are delivered in a tanker when bought loosed and in bulk.  The size of the delivery vehicle must be taken into consideration when planning the access.  These vehicles are mostly over 15 tonnes in weigh and can be between 3.7 to 3.9m high.  Therefore, check whether the access could be affected by weight restrictions, Narrow or steep access routes, tight bends or a lack to turning space.  Pellet storage areas should, where possible be located alongside an outside wall to leave the supply hoses as short as possible.  Because of fluctuating air volumes, handling with supply houses between 20 and 40 meters becomes difficult.  Supply tankers are equipped with a pump fan where pellets are blown into the storage area.