what is a flame
a flame is a chemical reaction between two or more chemicals that produces heat and light and other chemicals products of combustion for a constant flame to be maintained then there must be a method of renewing the supply of the two or more chemicalsusually convection a typical example of a flame is a candlethis is usually a rod of wax with a central wick the wick is ignited heat from the flame at the wick melts the wax the now liquid wax is absorbed by the wick and through capillary action the wax fuel is a fed to the flamehe rod has a small potential on it and when the flame touches it a small current flows from the rod through the flame to ground this current is detected and uses to prove the flame a flame acts as a diode but i don t recall the direction of electron flow and that effect isn t used in this application