Ravelli o-ring, User Manual

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how is a stove made? combustion
Combustion is nothing more than a chemical reaction in which two agents,
called the fuel and the oxidizing agent, combine to produce a new substance.
A considerable amount of heat is also produced from this reaction (concept of
pellet stove functioning).
To facilitate the aforementioned expression, we can take into consideration this
practical diagram called the “combustion triangle”; it consists of three elements
which are necessary to produce a combustion reaction. These three elements
are:
fuel (pellets)
oxidizing agent (oxygen in air)
trigger (electrical resistor on switch on).
The fuel and the oxidizing agent must be in adequate proportions because com-
bustion is restricted to the so-called “inflammability field”.
The reaction between the fuel and the oxidizing agent is not spontaneous, but
occurs using an external trigger.
The trigger can be represented for example by a heat source or a spark. The
trigger represents the ignition energy necessary for the reagent molecules to
start the reaction and must be provided externally (electrical resistor on switch
on). Then, the energy released by the reaction makes self-sustainment possible.
Three types of combustion are reported below, the correct one is reported in
Figure 3:
INCORRECT combustion
, flame too drawn, in “blow-
torch” style with a high quality of incandescent pellets
coming out of the grate. Correct the pellet/air set by
reducing the percentage of air (from 0 to -5); if not
sufficient, also increase the percentage of falling pel-
lets (from 0 to +5) to arrive to the condition in Figure
3. If the changes made to the settings do not bring the
stove to the right combustion conditions in Figure 3,
contact the Technical Support Centre.
INCORRECT combustion
, “spring” flame in “wood stove” style with high quan-
tity of pellets not burning on the grate. Firstly, check the door is closed and the
ash pan. Secondly, correct the pellet/air set by increasing the percentage of air
1
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9
11
10
2
3
4
5
6
6
12
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14
1
Pellet tank cover
2
Design coating
3
Pellet tank
4
Pelelt infeed screw
5
Smoke extractor
6
Pellet gear motor
7
Air intake duct with
flow meter
8
Hot air output grid
9
Vermiculite
10
Front door
11
Ignition resistance
12
Cast iron brazier
13
Fume duct
14
Stove base
fig.1
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