The Oxygen Effect on Mixture Flammability

Oxygen plays a duel role on mixture safety as a heat source and a heat sink. For the variable oxygen in a compartment (a type I problem), oxygen level in background air determines the upper limit of the fuel. For the oxygen in a fuel stream (a type II problem) in air, the oxygen will change the thermal properties of the fuel like a diluent or a fuel. Here both problems are solved with the thermal balance method. A new method, the flammable resistance method, can solve the type II problem more easily. It is equivalent with the thermal balance method, but with a perfect form like the Le Chatelier's Rule. Both methods are useful in assessing the danger of a flammable fuel stream containing oxygen.