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funcTIonaL prIncIpLe of THe HeaTIng sysTeM
3.2
How does the automatic pellet feed (option)
from the storage room work?
The pellets are extracted from the storage room either
directly via suction probes (Fig. 01), a mole system or by
means of a worm conveyor and then transported to the
pellet hopper on the boiler by means of a vacuum turbine.
The pellet hopper on the boiler includes two filling level
indicators:
•
for the signal "pellet hopper full“ / top
•
for the signal "pellet hopper empty“ / bottom on the
burner
The pellet hopper can only be filled during the preset en
-
able time in order to minimise the noise in the building.
The filling process is started every time the burner enters
burn-out mode or, at the latest, when the bottom filling
level indicator signals “empty.”
First, the suction turbine starts up.
Then, the mole (if fitted) or the discharge screw starts
operating after a delay of approx. 15 secs.
Discharge is stopped as soon as the upper filling level
indicator sends the signal for "pellet hopper full." If a mole
or a discharge screw are fitted, the suction turbine runs
on for a time in order to flush the hoses.
The extraction system can be disabled during two peri-
ods of time per day (e.g. to avoid unwelcome noise dur-
ing the night). The factory settings are from 12.30 p.m. to
15.30 p.m. and from 22.00 p.m. to 07.00 a.m. To ensure
that there is an adequate supply of pellets to span such
off-periods, forced burn-out with filling of the pellet hop
-
per is carried out 30 min. before the beginning of every
off-period. Off-periods can be deactivated by setting the
beginning and end of the respective period to 00.00 (see
Chapter 4.11.4).
Fig. 01