Burning Lycopodium Powder: Simulating a Grain Elevator Explosion
Overview
Lycopodium powder is a fine yellow powder derived from the spores of Lycopodium clavatum (stag’s horn club moss, running ground pine). When a lighted match is dropped into a pile of this powder, it does not burn. However, when the powder is dispersed into a fine mist near a candle flame, it ignites into a spectacular fireball.
Principle of Combustion
This phenomenon occurs due to an increased available surface area for combustion. When the powder is dispersed into a mist, the particles are surrounded by enough oxygen to support a combustion reaction.
Relation to Grain Elevator Explosions
This demonstration illustrates the basic principle behind a grain elevator explosion. Grain dust, like lycopodium powder, is not especially flammable. However, when grain is dumped into a grain silo or elevator, some of the finer dust particles can remain suspended in air, surrounded by oxygen. This mixture can be ignited by a spark or flame, resulting in a devastating explosion.
Fire Breathing Analogy
Fire breathing is a performance art that involves expelling a fine mist of fuel such as lycopodium powder; the increased surface area of the fuel in fire breathing allows for rapid combustion, illustrating how fine particles can lead to explosive reactions when mixed with oxygen.