3 Vitolig 300
12
3.3 Fuel storage and feed
General
Pellets are delivered in a tanker when
bought loose and in bulk. The size of the
delivery vehicle must be taken into
consideration when planning the access.
These vehicles are mostly over 15tonnes
in weight and can be between 3.7to
3.9 m high. Therefore, check whether the
access could be affected by weight
restrictions, subways, narrow or steep
access routes, tight bends or a lack of
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 hoses
between 20 and 40 m becomes difficult.
Supply tankers are equipped with a pump
fan, i.e. pellets are blown into the storage
area at a working pressure of 0.5 to
0.9 bar. The overpressure is then
withdrawn from the storage area by a
vacuum fan and filter installation. A
power supply with 230 V and at least 10 A
capacity is required.
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 m
3
(incl. empty
space) is calculated by multiplying the
required heat output (in kW) by a factor of
0.9 (m
3
/kW).
Example:
A detached house with a heat demand of
15 kW requires a storage volume of
approx. 13.5 m
3
incl. empty space (this
corresponds to a room of 2 x 3 m floor
area and a useable height of 2.25 m).
Storage room characteristics and fuel feed with all necessary system components
H
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).
H
The pellet storage area must be
constructed as a solid, leak−proof
structure, since blowing pellets into this
room will create dust and blowing
pellets against the walls creates high
pressure.
H
Surrounding walls and ceiling must
correspond to fire resistance class F 90,
e.
g. house bricks 12 cm, rendered on
both sides; hollow breeze block 17 cm,
rendered on both sides; concrete 10 cm,
plaster slab 12 cm.
H
Doors or access hatches into the pellet
storage area must open outwards and
must be sealed. Ensure the doors or
hatches are constructed as fire doors
T 30 or, if necessary, T 90.
H
Fit protective boards
A
on the inside of
the door opening, so that pellets do not
push against the door (see page 13).
H
The pellet storage area should not
contain any electrical installations.
Essential electrical installations must be
of the explosion−proof type in
accordance with current regulations.
H
Avoid the installation of water pipes
inside the storage area because of
condensation and the risk of burst
pipes.
H
Pellet storage areas should be equipped
with a filling
F
and a return air adaptor
G
with Storz system type A
Ğ
100 mm
coupling (fire hose adaptor) with
extension hose leading into the storage
area. Pipes should be metal (not
plastic), and should be connected to the
brickwork and must be earthed.
H
A deflector
B
should be fitted opposite
the filling adaptor to protect the pellets
and the brickwork.
H
The pellet storage area must be free
from debris (small stones, wood
particles, etc.).
H
Distribute the suction wands
H
so that
the storage area is efficiently emptied.
H
The maximum length of the feed and
return hoses
E
and the maximum
height of the suction wand, which is the
furthest removed from the feed unit
should not be greater than 15 m in
length or 2.8 m in height. Hoses should
be earthed, may not be installed on the
outside and should be protected
against temperatures above 60
º
C.
H
Close the wall opening for the
automatic changeover unit
D
from the
storage room side in a fireproof manner
(e.g. rendering).
5822241 GB
