Diffusioonipõlemise

Diffusioonipõlemine is a type of combustion where fuel and oxidizer mix in the reaction zone. Unlike premixed flames where fuel and oxidizer are mixed before ignition, in diffusion flames, the mixing occurs simultaneously with the combustion process. This means the reaction rate is primarily controlled by the diffusion rate of the reactants.

The most common examples of diffusion flames are candle flames, oil lamps, and gas stoves that are not specifically designed for premixed combustion. In these scenarios, fuel vapor or gas diffuses from a source into the surrounding air, where it mixes with oxygen. The combustion then occurs at the interface where sufficient concentrations of both fuel and oxidizer are present.

The appearance of a diffusion flame is often characterized by its visible flame front, which can be yellow or orange due to incandescent soot particles formed during incomplete combustion. The shape and size of the flame are influenced by factors such as fuel flow rate, oxygen availability, and the geometry of the burner or fuel source. Diffusion flames can be less efficient than premixed flames because the mixing process can be slower and less uniform, leading to incomplete combustion and the production of pollutants like carbon monoxide and soot. However, they are often simpler to implement in practical applications and can be more stable under certain conditions. The study of diffusion flames is important in understanding fire safety, the design of combustion engines, and various industrial burning processes.