Flame color and temperature

The color of a flame is closely related to its temperature and the completeness of the combustion process. 

Here is a breakdown of the relationship between flame color and temperature:

Flame Color and Temperature

Blue Flame:

Temperature: Typically indicates high temperatures, usually above 1,000 °C (1,832 °F).

Characteristics: A blue flame usually indicates complete combustion, where the fuel is burning efficiently with sufficient oxygen. 

This is common in natural gas burners, ideal for heating applications.

Yellow Flame:

Temperature: Typically indicates lower temperatures, usually around 800 °C to 1,000 °C (1,472 °F to 1,832 °F).

Characteristics: Yellow flames are usually caused by incomplete combustion, that is, insufficient oxygen. 

This results in the production of soot or carbon particles, which glow yellow when heated. Common in oil burners or when burning wood.

Orange Flame:

Temperature: Similar to the yellow flame, typically around 700 °C to 900 °C (1,292 °F to 1,652 °F).

Characteristics: An orange flame may indicate inadequate combustion and higher soot production. 

This color may also be caused by certain impurities in the fuel.

Red flame:

Temperature: Typically the coldest of the above flames, usually less than 700 °C (1,292 °F).

Characteristics: A red flame usually indicates very inefficient combustion and may indicate that the fuel is burning at low temperatures.

It may occur in a misadjusted burner or in specific combustion scenarios.

White flame:

Temperature: Indicates extremely high temperatures, usually over 1,200 °C (2,192 °F).

Characteristics: A white flame may indicate very efficient combustion at high temperatures, often found in certain industrial processes or specialty burners.

Summary

Higher temperatures: Typically correspond to blue or white flames, indicating complete and efficient combustion.

Lower temperatures: Typically correspond to yellow, orange, or red flames, indicating incomplete and less efficient combustion.

Understanding the relationship between flame color and temperature is critical to optimizing the combustion process, increasing energy efficiency, and ensuring safety in a variety of applications.