why do candle's smoke so much after you blow them out?

Question

I know there's some smoke while it's burning. but when you blow them out and the wick is still glowing a little, lots and lots of smoke comes out. why is this? what's the difference between flame and glowing? and why does the glowing make so much more smoke?

Answer 1

Ever see a fire after the flames have gone out? Same deal with your candle. The combustion process is still going on it is just not vigorous enough to drive vapors high enough to produce a flame.

While the flame is going the reaction is much faster and much more heat is being released. Consequently more organic vapors are escaping un-burned. A “rich burn” situation as a mechanic might call it.

Once the flames are out combustion is slower and more complete. Air gets right to the site of combustion, “lean burn”. As the burning is occurring small pieces of charred debris from the wood, or in this case the candlewick and wax, are carried away by the air currents and the heat. It is these bits that you see, tiny pieces of charcoal.

Ordinarily the wick does not get as hot while the candle burns as it dose after the flame is out so less visible smoke is made. Plus those bits are more completely burned in the flame, so what does come out is more black and less gray.

Answer 2

The actual fire in a candle is from the vapors that surround the wick. The solid candle melts and then the liquid vaporizes. When you blow the candle out, there are uncombusted hydrocarbon vapors still remaining. They cool down and turn into smoke.

Answer 3

You just need to trim the wick before you light it. There are different kinds of wicks too. Some burn at a different heat than others, so when you blow them out...some smoulder and some don't.