3. Oxidizing power – Smoking power – Excess air

3.1 Too much or too little air

Theoretical combustion of a fuel involves burning all the elements of that fuel in accordance with the stoichiometric equations. This is an ideal case, rarely realized in practice, but whose study serves as a basis for that of real combustion.

Theoretical combustion requires a precise quantity of air (or oxygen) for a given mass or volume of fuel. In relation to this quantity, actual combustion takes place with :

• or an excess of air → combustion is said to be oxidizing;

• or a lack of air → combustion is said to be reductive.

Moreover, in practice, the temperature of the flue gases differs significantly from that of...