How it Works – Roman Candle

One of my last assignments in my high school was investigating how fireworks work. For that I made a simple animation. In this article we will see how to Roman Candle works, without using too difficult chemistry terms.

The Roman Candle is a very common piece of fireworks, that is pretty popular for private use. It is usually made from a cardboard cylindrical shaped cover, closed at one end and open at the other (the ‘launch-end’). The operation is displayed in the movie below, where you can see a section view.

In the section view it is possible to distinguish different chemical substances.

The red balls can clearly be identified as ‘stars’. They will produce a red color when burned. Strontium salts or lithium salts can be involved here, since they produce a red color when burned. What we else have is the fuse, which must be ignited to get to the level of activation energy. The means that the chemicals will not show any reaction on a certain energy level, for example on room-temperature. This also explains why you shouldn’t throw your fireworks on the heating . After the level of activation energy is reached, the chemicals will react and the level of energy will increase a lot. This energy can be hold responsibly for effects we see in fireworks. But let’s get on witht he Roman Candle.

We also distinguish yellow and grey areas. The yellow works as the delaying agent, generating a time interval between the lauching of the stars. Thus it is logical is burns relatively show, generating very few energy. The grey is the launching fill. It burns very fast, thereby generating enough pressure to propulse a star fast. Depending on how much and how the strong the launching fill is, the star will even be able to reach a pretty nice height. There is a lot more theorem about chemicals in fireworks and how this works, but I hope this introduction was clear enough to show how a Roman Candle works.