Difference Between Oxidizing and Reducing Flame

Thekey differencebetween oxidizing and reducing flame is thatoxidizing flames are produced in the presence of an excessive amount ofoxygen, whereas reducing flames are produced in the presence of a low level of oxygen.

We use various types of burners in different applications; for example, Bunsen burner in analytical laboratories. These burners produce different flames depending on the amount of oxygen around the burner. These flames can be categorized as oxidizing, reducing and neutral flames.

1.Overview and Key Difference
2.What is Oxidizing Flame
3.What is Reducing Flame
4.并排比较 - 氧化与减少表格形式的火焰
5.概括

What is Oxidizing Flame?

Oxidizing flame is the burner flame that is produced in the presence of an excessive amount of oxygen gas. When there is an excessive amount of oxygen gas around the burner, the burner produces a shortened flame. This short flame also has a dark colour. Furthermore, the oxidizing flame tends to be hissing and roaring as well.

Key Difference - Oxidizing vs Reducing Flame

图01：富含氧气的周围形成了短火焰

Generally, this type of flame is undesirable for welding purposes. This is because this oxidizing flame can oxidize the metal surface, as its name suggests.

What is Reducing Flame

Reducing flame is the burner flame that is produced in the presence of a low level of oxygen gas around the burner. Usually, when there is not enough oxygen around the burner, the flame becomes yellow or yellowish. This is due to the presence of carbon or carbon-containing compounds such ashydrocarbons. The carbon atoms tend to combine with the oxygen atoms and form a reducing flame. Therefore, this type of flame is also known as a carburizing flame. This is because this flame can introduce carbon into molten metal. Reducing flames are important in soldering and annealing.

Difference Between Oxidizing and Reducing Flame

图2:不同的火焰——还原焰(左most) and Oxidizing Flame (rightmost)

另一方面，中性火焰也很重要solderingandannealing. This type of flame is produced when there is enough oxygen gas around the burner, but the oxygen content does not exceed the limits of the requirement for oxygen. Therefore, neither oxidation or reduction occurs here. These flames appear in blue colour because there is a good balance of oxygen.

What is the Difference Between Oxidizing and Reducing Flame?

不同的燃烧器会根据燃烧器周围的氧气量产生不同的火焰。氧化和还原火焰之间的关键区别在于，在存在过多的氧气的情况下会产生氧化火焰，而在低水平的氧气存在下，还会产生还原的火焰。氧化火焰可以氧化金属表面，而还原火焰可以减少熔融金属。因此，氧化火焰不适合焊接和退火目的，但是减少火焰是这两种应用的理想选择。

Moreover, a visible difference between oxidizing and reducing flame is that oxidizing flames are short and have dark colours while reducing flames are long and yellow or yellowish.

您可以在下面的信息图中找到更多细节，这些信息图是氧化和减少火焰之间的差异。

概括– Oxidizing vs Reducing Flame

不同的燃烧器会根据燃烧器周围的氧气量产生不同的火焰。氧化和还原火焰之间的关键区别在于，在存在过多的氧气的情况下会产生氧化火焰，而在低水平的氧气存在下，还会产生还原的火焰。

Reference:

1. “Oxidizing Flame.” Oxidizing Flame – an Overview | ScienceDirect Topics,Available here.
2. “Oxidizing and Reducing Flames.” Wikipedia, Wikimedia Foundation, 22 May 2018,Available here.