ChilliP-A5-Eco-Manual-2020-Download

4.f Principles of Combustion

Allfuelsneedthepresenceofoxygentoburn.Themoreoxygenaregetsthehotter

andfasteritwillburn.When,whereandhowairisintroducedintoareboxofastove

willgreatlyinuencetheheatoutput,burningrate,fueleciencyandimpactonthe

environment.Dierentfuelsburnindierentwaysanditisimportanttoknowthe

basicsinordertooperateyourstovewithcondence.

WOOD

Woodneedstobeseasoned(cutandstoredforatleastoneyearaftercutting)orkiln

driedpriortoburninginthestovewithamoisturecontentoflessthat25%.Asafuel

itgivesagoodameandareasonablyhighheatoutput,theburnrateishighandwill

varyconsiderablydependingonsizeandspecies.Woodrequirescombustionairtobe

directeddownontoittoburnmosteciently.Thesecondarycombustionairsupplyon

yourstoveprovidestheairnecessaryforburningothevolatilegases

Tips for identifying dry wood

1)Visiblecracksattheendofthelog

2)Bangtwologstogether,theywillsoundhollow

3)Woodmoisturecontentmeasuringdevicesareavailable

There are 3 stages in the burning of wood

stage 1

Dryingout.Whenapieceofwoodentersthereboxitwillstaybelowtheboilingpointof

water(100°C)untilallthemoisturehasbeendrivenout.Between150–200°Cwoodbegins

togiveovolatilegases,someofthesewillburnwhileotherswillmixwiththecarbondioxide

andwatervapourandbecarriedoutthechimneyassmoke.

stage 2

Inthesecondstageofcombustiontemperaturesmustreach600°Cforthegasestostart

burningo.Thiswillonlyoccurwiththerightamountofairandheatleadingtohigher

eciencies.Thesegasesburnasayellowameabovethewood.

stage 3

Charcoalisleftonceallthegaseshavebeenburnto.Thecharcoalcontainsatleasthalf

ofthewood’sheatpotential,atthisstagetherewillburnmoreslowlyandwithoutame

requiringlessair.

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