Flame temperature: What is it?

Headnote

WHAT DOES A HOLEY BUCKET HAVE TO DO WITH MY OVEN?

In this business, the term "flame temperature" gets kicked around a lot. It doesn't take too long before you realize it means different things to different people. To some, it's the temperature of the combustion chamber the flame occupies. To others, it means the temperature of that glowing jet of gases coming out of a burner. To still others, it's a number quoted with authority from a handbook, while others will tell you that number is never seen in real life. In most practical situations, it really doesn't matter, as long as the heat processing equipment gets the job done. Just the same, life would be easier if everyone had a common understanding of the concept.

Well, here goes. But first, I'll define a few terms I'll be using along the way.

Adiabatic is a term used to describe a combustion reaction in which all heat generated is retained in the products of combustion none is lost to the flame's surroundings.

Dissociation is a reaction involving the breakdown of chemical compounds. In the case of combustion, these are water vapor and carbon dioxide.

Stoichiometric is not an imported vodka. It describes correct mixture of ingredients in a chemical reaction. After the reaction is over, no surplus ingredients will be left. In combustion, the stoichiometric ratio also is called correct, ideal or perfect ratio.

The flame temperatures published in handbook tables usually are adiabatic flame temperatures for combustion at stoichiometric ratio. Unless specified otherwise,...