Tuesday, January 10, 2017

What are some of the most interesting little-known things?

You may have seen trick candles before that magically relight after being blown out, but do you know how they work?



​These trick candles actually have magnesium incorporated into the wick. For a flame to continue burning, it needs 3 things: oxygen, fuel, and heat. These are often represented graphically as a fire triangle.

First, let’s understand how a regular candle works. A lit candle melts the wax near it, absorbs it, and draws it upwards. The burning flame vaporizes the wax, which burns and keeps the flame lit. This cycle can continue until all the wax fuel has been used up.

When you blow at an ordinary candle, it extinguishes because of the rapid removal of heat from the wick.

The ember in an ordinary candle is unable to supply enough heat to reignite the hot vapour of paraffin hydrocarbons which surround the wick, causing the flame to die off. If you look at a candle that has just been blown out closely, you might be able to see a wisp of smoke rising from the wick. That’s actually the paraffin vapour formed from the dying ember-  it doesn’t ignite because the flame isn’t hot enough.

In a trick candle however, things work differently. The magnesium that is incorporated into the wick is able to catch fire at relatively low temperatures of 430 degrees Celsius when it is powdered. The burning magnesium emits sparks which light up the paraffin vapour surrounding the wick, and the candle relights!


Read other answers by Rozalin Mohanty on Quora: Read more answers on Quora.

from Quora http://ift.tt/2icVwDp

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