Abstract: A crossfire tube assembly joining adjacent combustors in a gas turbine engine includes an impingement sleeve within which a crossfire tube is centrally disposed. The impingement sleeve is pierced by an array of impingement cooling holes which form a plurality of small jets of cooling air impinging upon, and cooling, the crossfire tube. The space between the impingement sleeve and the crossfire tube forms a flow channel along which the spent impingement air flows in the axial direction before exiting into the interiors of the combustors. A flow dam at the center of the flow channel forces the impingement air to flow toward the ends. An outward flare in a portions of the crossfire tube extending beyond the extremity of the impingement sleeve directs air exiting the flow channel upon an annular flange which supports the crossflow assembly and thus improves cooling in this area.

Abstract: A catalytic combustor comprises a pilot zone having means to introduce fuel therein; upstream of said pilot zone and communicating therewith a catalytically supported thermal combustion zone comprising a plurality of catalytically supported thermal combustion sections each comprising a solid oxidation catalyst, means for introducing air into said section and means to introduce fuel into said section; and means to control the rate of fuel flow in each of the means to introduce fuel into a catalytically supported thermal combustion section and the means to introduce fuel into the pilot zone. The combustor is operated by staging the fuel supply in order to maximize the amount of combustion in the catalytically supported thermal combustion zone and minimize NOx emissions under all load conditions.

Abstract: An improved dual stage-dual mode combustor capable of reduced emissions of nitrogen oxide from a combustion turbine is disclosed. The combustor includes two combustion chambers separated by a throat region. Fuel is initially introduced and ignited in the first chamber. Thereafter, fuel is introduced near the downstream end of the first chamber for ignition and burning in the second chamber. Burning in the first chamber is extinguished by shifting the fuel flow to burning in the second chamber and after termination of the flame in the first chamber, fuel is reintroduced into the first chamber for premixing only with burning in the second chamber. By selectively controlling the percentage of fuel introduced into the first stage, low emissions of nitrogen oxide are realized.