Fuel-air mixing and flame stabilization device for a low emission burner with internal flue gas recirculation
A flame stabilization apparatus with fuel injection upstream of a torpedo, includes a flame stabilization plate that incorporates spokes that stabilize a flame over a range of operations of a burner. The spokes surround a fuel plenum with respect to the burner. A first group of fuel ports can be located in a fuel tube upstream of the torpedo and a second group of fuel ports can be located in the flame stabilization plate. A discharge cone includes a discharge zone for the burner, wherein the flame with respect to the flue gas is stabilized at an end of the burner in the discharge zone.
1 . A flame stabilization apparatus with fuel injection upstream of a torpedo, comprising:
a flame stabilization plate that includes a plurality of spokes that stabilizes a flame over a range of operations of a burner, wherein the plurality of spokes surrounds a fuel plenum;
a first group of fuel ports located in a fuel tube upstream of the torpedo and a second group of fuel ports located in the flame stabilization plate; and
a discharge cone comprising a discharge zone for the burner, wherein the flame with respect to the flue gas is stabilized at an end of the burner in the discharge zone, wherein the torpedo comprises a diverging conical section that reduces an area of a mixing zone of the burner and allows the flue gas and the air to interact.
2 . The flame stabilization apparatus of claim 1 wherein the burner comprises a refractory block, the refractory block including a plurality of flue gas ports, wherein a flue gas is pulled into the burner from the plurality of flue gas ports.
3 . The flame stabilization apparatus of claim 1 wherein the burner includes a mixing zone, wherein the flue gas mixes with air in the mixing zone.
4 . The flame stabilization apparatus of claim 1 wherein the torpedo comprises a fuel supply pipe that connects to the discharge cone and to a fuel plenum tube, wherein the discharge cone surrounds the fuel supply pipe .
5 . The flame stabilization apparatus of claim 1 , wherein the discharge cone includes the diverging conical section.
6 . The flame stabilization apparatus of claim 1 wherein the torpedo achieves stability with respect to the flame with NOx levels of less than 25 ppm.
7 . The flame stabilization apparatus of claim 1 wherein the torpedo achieves stability with respect to the flame with a turn-down rate of 10:1 or higher.
8 . A method of operating a flame stabilization apparatus with fuel injection upstream of a torpedo, comprising:
injecting fuel into an air stream at an entrance to the torpedo from a fuel tube of a burner; and
stabilizing a flame with a flame stabilization plate that includes a plurality of spokes surrounding a fuel plenum, wherein a first group of fuel ports is located in the fuel tube upstream of the torpedo and a second group of fuel ports is located in the flame stabilization plate, and the flame with respect to the flue gas is stabilized at an end of the burner in a discharge zone of a discharge cone, wherein the torpedo comprises a diverging conical section that reduces an area of a mixing zone of the burner and allows the flue gas and the air to interact.
9 . The method of claim 8 wherein the burner comprises a refractory block, the refractory block including a plurality of flue gas ports, wherein a flue gas is pulled into the burner from the plurality of flue gas ports.
10 . The method of claim 8 wherein the burner includes a mixing zone, wherein the flue gas mixes with air in the mixing zone.
11 . The method of claim 8 wherein the torpedo comprises a fuel supply pipe that connects to the discharge cone and to a fuel plenum tube, wherein the discharge cone surrounds the fuel supply pipe.
12 . The method of claim 8 , wherein the discharge cone includes the diverging conical section.
13 . The method of claim 8 , wherein the torpedo achieves stability with respect to the flame with NOx levels of less than 25 ppm.
14 . The method of claim 8 , wherein the torpedo achieves stability with respect to the flame with a turn-down rate of 10:1 or higher.
15 . A flame stabilization apparatus, comprising:
a flame stabilization plate that includes a plurality of spokes that stabilizes a flame over a range of operations of a burner; and
a discharge cone comprising a discharge zone for the burner, wherein a flame with respect to the flue gas is stabilized at an end of the burner in the discharge zone; and
a torpedo that includes a diverging conical section that reduces an area of a mixing zone of the burner and allows the flue gas and the air to interact, the discharge cone including the diverging conical section.
16 . The flame stabilization apparatus of claim 15 wherein the burner comprises a refractory block connected to the flame stabilization plate, the refractory block including a plurality of flue gas ports, wherein a flue gas is pulled into the burner from the plurality of flue gas ports.
17 . The flame stabilization apparatus of claim 15 wherein the burner includes a mixing zone, wherein the flue gas mixes with air in the mixing zone.
18 . The flame stabilization apparatus of claim 15 comprises a fuel supply pipe that connects to the discharge cone and to a fuel plenum tube, wherein the discharge cone surrounds the fuel supply pipe.
19 . The flame stabilization apparatus of claim 18 wherein the torpedo achieves stability with respect to the flame with NOx levels of less than 25 ppm.
20 . The flame stabilization apparatus of claim 18 wherein the torpedo achieves stability with respect to the flame with a turn-down rate of 10:1 or higher.