Patent ID: 7402038

Claim:
A method comprising: delivering fuel and oxidant to a combustion chamber at target rates that together have a target fuel-to-oxidant ratio, while delivering no additional oxidant to the combustion chamber, by: a) delivering the entire target rate of oxidant and a first partial target rate of fuel together in a fuel-lean primary reactant stream that is directed into the combustion chamber along an axis to define a primary combustion zone expanding radially outward along the axis; b) simultaneously delivering a second partial target rate of fuel in second stage fuel streams that are injected into the combustion chamber at locations radially outward of the primary reactant stream to define a secondary combustion zone radially outward of the primary combustion zone; and c) simultaneously delivering the balance of the target rate of fuel at a third partial target rate in third stage fuel streams that are injected into the combustion chamber at locations within the primary reactant stream to define a tertiary combustion zone extending axially downstream from the primary combustion zone.