What is the main characteristic of diffused flames in combustion?

Diffused flames are primarily characterized by their association with pyrolysis, which refers to the thermal decomposition of materials at elevated temperatures in an inert atmosphere. During this process, solid fuels undergo chemical changes, and volatile gases are released. The combustion of these gases leads to the diffused flame, typically seen when air mixes with these volatiles, allowing combustion to occur in a broader and less defined area rather than at a single, concentrated point.

The association with pyrolysis highlights that diffused flames often emerge in scenarios where materials are not fully ignited, and the combustion is influenced by the slow release of gases from decomposing solids. This results in flames that can appear more widespread and less uniform, setting them apart from flames that are characterized by uniform burns or occur in more controlled environments.