Pelltech PV 20a, User Manual, Page: 11 / 43

PV20a / PV30a pellet burner
page
11/ 41
DK9902A1 www.pelltech.eu
Table 2 Wood pellets properties
Raw material Sawdust,cutter shavings and stem wood
Calorific value 4700-5100 kWh/ton
Bulk density ca 650-670 kg/m
3
Volume of 1 ton 1.5-1.6 m
3
Diameter 6-8 mm
Length 3-5 x diameter
Fines content (<3,2 mm) <0,5%
Moisture content 8-10 %
Ash content < 1%
Ash fusion > 1200
o
C
To replace 1000 l light oil ca 2 tons or 3 m
3
Burner, external auger and container are common system. The size and location of the pellet container
depends on the needs and possibilities of bolier room or boiler room. While choosing the pellet
container you must keep in mind that:

if the pellet container is in the same room as the boiler, then the size of the pellet container
must not exceed 500 liters (approx. 350kg).

the container must be made of fireproof materials.

the container must be positioned in a way that the raising angle of the feeding auger does not
exceed 45°. Figure 11.

the container could be closed with a cover.
2 Installation
Requirements to the boiler and boiler room 2.1
In order to install the burner, the boiler must correspond to the following requirements:

The door of the boiler must have a 90 mm opening (placement opening for the oil burner).

The thickness of the boiler door must be less than 100mm

The construction of the boiler must make it possible to open the door of the boiler with the
burner connected and removing ash from the furnace. If the door of the boiler is too narrow for
opening it with the burner, then extra hinges must be installed.

If there is not sufficient negative pressure (less than - 5Pa)in the furnace, a flue gas fan should
be installed for the exhaust gases.

The boiler room where the burner is installed must fulfill all rules and recommendations given
by authorities.

The boiler must be positioned in a way that there is enough space for cleaning the burner, the
boiler and the smoke pipe and removing the ash.
If flue gas temperature at the top of the chimney is less than 80C
o
, there is a risk of condensation. This
makes pitch and brakes into pieces stone chimney. In this case a stainless steel pipe should be installed
into the chimney.
Notice: It is recommended to use a flue gas analyzer for adjusting the burner. The burner must be
adjusted also when you use pellets with different quality.
Pellet burners need regular cleaning and therefore boiler construction must allow the door to be
opened without removing the burner. The minimum size of opening in boiler depends on the position of
door hinges. Figure 4 below illustrates the situation. Point C is critical.