When does a non-seated explosion occur?

A non-seated explosion occurs when the fuels are dispersed or diffused at the time of the explosion. This type of explosion is characterized by the presence of a fuel-air mixture that is not contained within a specific area, allowing the explosion to involve a broader, more distributed volume of combustible gas or vapor. The rapid mixing of fuel and air leads to a fast increase in pressure and temperature, often resulting in a violent reaction.

In contrast, a seated explosion involves fuel that is compacted in a confined space, leading to a concentration of energy release in a specific location. When ignition occurs in such conditions (like in an enclosed vessel) the energy is released in a more contained manner. Rapid cooling effects do not directly relate to explosion types but rather affect how fire and combustible materials behave post-explosion.