Emptying The Ash Drawer; The Combustion Process; Drying Phase; Degasifi Cation Phase - HASE Akaba Mode D'emploi

14. Emptying the Ash Drawer

For safety's sake, please make sure that you only dispose of ashes once they are cold. While
the ash collects, the lid is located under the ash drawer.
Unlock the ash drawer. Remove both the ash drawer and the lid located underneath it.
Slide the lid onto the ash drawer so that it is closed; this prevents ashes from fl ying around,
which in turn means your home stays clean. To place the ash drawer back into the stove,
proceed in the reverse order.
Piled up ashes can prevent or even block the primary air supply to the stove.
Ensure that the ventilation path for the primary air between the ash drawer and
the bottom of the ash compartment remains clear.

15. The Combustion Process

A piece of wood burns in three phases. In a wood fi re, however, these processes take place
both consecutively and simultaneously

15.1 Drying Phase

The moisture still remaining in the air-dried wood (approx. 15 - 20%) is evaporated.
This takes place at temperatures of approx. 100°C. For the evaporation to occur, the wood
must be supplied with heat during the warming up phase; this is achieved by using small
wood logs.
15.2 Degasifi cation Phase
At temperatures of between 100°C and 150°C, the contents of the wood start (slowly at
fi rst) to disintegrate and gasify and the wood begins its thermal decomposition. At tem-
peratures above 150°C, the gas development increases strongly. The proportion of volatile
components makes up around 80% of the wood substance.
At a temperature of about 225°C (ignition temperature), the actual combustion begins
with the ignition of the resulting gases and the release of heat. There must be an adequate
supply of oxygen available for this purpose. The peak of the combustion process is reached
at approx. 300°C. The reaction process is now so rapid that the largest amount of heat is
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released at this point; fl ames can reach temperatures of up to 1100°C.

15.3 Burn-off Phase

Glowing charcoal embers remain after the volatile components have been burned off.
These burn slowly, almost without fl ames, at a temperature of approx. 800°C.
Crucial to a clean and effi cient combustion process is a complete (as possible) chemical
reaction of the wood gases with the oxygen in the combustion air. With your Hase stove,
the combustion air is pre-heated and guided into the fi re box via wide air inlet openings,
enabling a good and thorough mixing of the gases with the air. An important variable in any
combustion phase is the amount of combustion air.
Not enough air leads to an oxygen defi ciency and incomplete combustion, while too much
air reduces the fi re box temperature and thus the effi ciency. Incomplete combustion can
Fig. 5 The Combustion Process
Degasifi cation
Drying
Burn-off