PilotedIgnitionPiloted Ignition:Flame is initiated byanexternalhigh-energy sourcee.g.electricalarc,spark, orasmall flame,differentfromautoignition.A spark is used in the ignition of wood (cone calorimetertest)Aflamepiloted byasmallflame(lighter)16FireScienceDrXinyanHuang
Fire Science 16 Dr Xinyan Huang Piloted Ignition Piloted Ignition: Flame is initiated by an external high-energy source, e.g. electrical arc, spark, or a small flame, different from autoignition. A spark is used in the ignition of wood (cone calorimeter test) A flame piloted by a small flame (lighter)
PilotedIgnitionTimeandStepsHowtoigniteacandleorsolidfuels?InmostfireapplicationsStep1:Heatthesolidfuel intensivelytogeneratefuelIgnition timeHeating timegases,i.e.,pyrolysis (10s~min)(Step 1)Step2:Fuelgasesmixwithair(~1s)Step3:Pilottheflammablemixturebyflameorspark(~ms)HeatfluxPilotFlammablemixtureTemperature(11)(12)ambient(to)(13)lonuontimeFire Science17DrXinyanHuang
Fire Science 17 Dr Xinyan Huang Piloted Ignition Time and Steps How to ignite a candle or solid fuels? Step 1: Heat the solid fuel intensively to generate fuel gases, i.e., pyrolysis (10 s ~ min) Step 2: Fuel gases mix with air (~ 1 s) Step 3: Pilot the flammable mixture by flame or spark (~ms) In most fire applications Ignition time ≈ Heating time (Step 1)