Patent ID: 7425127

Claim:
A method of combusting reactants including a fuel and an oxidizer, comprising the actions of: a. directing the reactants from a nozzle into a combustion chamber so that a fuel flow is surrounded and shielded by a concentric oxidizer flow; b. igniting the reactants to initiate combustion in the combustion chamber, thereby generating a flame and combustion products; c. reducing velocity of the reactants inside the combustion chamber so as to anchor part of the flame relative to the combustion chamber adjacent to a stagnation zone; d. mixing a portion of combustion products with the oxidizer flow in a non-combusted portion of the reactants between the nozzle and the flame by redirecting the combustion products so as to flow coaxially outside of the oxidizer flow, in a direction counter thereto, so that the combustion products come in contact with the oxidizer flow, thereby forming a shear layer between the combustion products and the oxidizer flow and so that combustion products mix with the oxidizer flow in the shear layer, thereby maintaining combustion of the reactants at a temperature that is lower than would be obtained if the portion of the combustion products were not mixed with the oxidizer flow; and e. exhausting the combustion products coaxially about the reactants flowing into the combustion chamber in a direction that is opposite to the reactants flowing into the combustion chamber.