LOW NOx NOZZLE TIP FOR A PULVERIZED SOLID FUEL FURNACE

• US 20090277364A1
• Filed: 02/26/2009
• Published: 11/12/2009
• Est. Priority Date: 03/07/2008
• Status: Active Grant

• Current Assignee: General Electric Technology GmbH (GE Vernova, Inc.)
• Original Assignee: Alstom Technology Ltd. (Alstom SA)
• Inventors: Richards, Galen H., Donais, Richard E., Hellewell, Todd D., Towle, David P., Lewis, Robert D.
• Granted Patent: US 8,701,572 B2
• Time in Patent Office: Days
• US Class Current: 110/263
• CPC Class Codes: F23C 7/008 Flow control devices F23C7/006 takes precedence
• CPC Class Codes: F23D 1/00 Burners for combustion of pulverulent fuel disposition of burners F23C
• CPC Class Codes: F23D 2201/101 tiltable
• CPC Class Codes: F23D 2201/20 Fuel flow guiding devices

Abstract

A nozzle tip [100] for a pulverized solid fuel pipe nozzle [200] of a pulverized solid fuel-fired furnace includes: a primary air shroud [120] having an inlet [102] and an outlet [104], wherein the inlet [102] receives a fuel flow [230]; and a flow splitter [180] disposed within the primary air shroud [120], wherein the flow splitter disperses particles in the fuel flow [230] to the outlet [104] to provide a fuel flow jet which reduces NOx in the pulverized solid fuel-fired furnace. In alternative embodiments, the flow splitter [180] may be wedge shaped and extend partially or entirely across the outlet [104]. In another alternative embodiment, flow splitter [180] may be moved forward toward the inlet [102] to create a recessed design.

Claims

1. A nozzle tip [100] for a pulverized solid fuel pipe nozzle [200] of a pulverized solid fuel-fired furnace that reduces NO_X emissions, the nozzle tip [100] comprising:

a primary air shroud [120] having an inlet [102] and an outlet [104], wherein the inlet [102] receives a fuel flow;

a first splitter plate [160] disposed within the primary air shroud [120], the first splitter plate [160] and the primary air shroud [120] defining a duct [260] for receiving a first portion of the fuel flow; and

a flow splitter [180] disposed within the primary air shroud [120], the flow splitter [180] having a pair of diverging surfaces which separates a second portion of the fuel flow [230] into a first split flow and a diverging second split flow, wherein the first split flow and the first portion of the fuel flow [230] combine at the outlet [104] of the primary air shroud [120] to provide a first outlet fuel jet which exits the outlet [104] of the primary air shroud [120] separate from the second split flow.

2. The nozzle tip [100] of claim 1, wherein

the first outlet fuel jet and the second split flow exit the outlet [104] of the primary air shroud [120] separate and discrete from each other, and

the first outlet fuel jet and the second split flow remain separate and discrete from each other for a predetermined distance from the outlet [104] of the primary air shroud [120].

3. The nozzle tip [100] of claim 1, further comprising at least one of a shear bar [170] and a bluff point disposed on the first splitter plate [160].

4. The nozzle tip [100] of claim 1, further comprising a secondary air shroud [110] disposed around the primary air shroud [120].

5. The nozzle tip [100] of claim 1, wherein the primary air shroud [120] comprises:

side plate [122];

a top plate [124]; and

a bottom plate [126], wherein the top plate [124] and the bottom plate [126] connect the side plate [122] together.

6. The nozzle tip [100] of claim 1, further comprising a second splitter plate [160] disposed within the primary air shroud [120], the second splitter plate [160] and the primary air shroud [120] defining a duct [280] for receiving a third portion of the fuel flow [230].

7. The nozzle tip [100] of claim 6, wherein the flow splitter is disposed between the first splitter plate [160] and the second splitter plate [160].

8. The nozzle tip [100] of claim 6, wherein the second split flow and the third portion of the fuel flow [230] combine at the outlet [104] of the primary air shroud [120] to provide a second outlet fuel jet which exits the outlet [104] of the primary air shroud [120] separate from the first outlet fuel jet.

9. The nozzle tip [100] of claim 2, wherein

the predetermined distance is in a range of approximately two (2) diameters of the first outlet fuel jet to approximately eight (8) diameters of the first outlet fuel jet, and

the first outlet fuel jet and the second split flow at least partially combine after traveling the predetermined distance from the outlet [104] of the primary air shroud [120] into the pulverized solid fuel-fired furnace.

10. The nozzle tip [100] of claim 6, wherein

the first portion of the fuel flow [230] comprises approximately 30 percent of the fuel flow [230],

the second portion of the fuel flow [230] comprises approximately 40 percent of the fuel flow [230], and

the third portion of the fuel flow [230] comprises approximately 30 percent of the fuel flow [230].

11. The nozzle tip [100] of claim 8, wherein

the first outlet fuel jet and the second outlet fuel jet each comprise approximately 50 percent of the fuel flow [230].

17. The nozzle tip [100] of claim 1 wherein the first splitter plate [160] substantially bisects the outlet [104] generally through at an approximate center, and

the flow splitter [180] comprises:

a wedge shape having an apex edge [483] and a base [481], the apex edge [483] positioned closer to the inlet [102] and the base [481] positioned closer to the outlet [104], the flow splitter [180] extending only partially across the outlet [104], the flow splitter [180] creating turbulence in the fuel flow [230] that disperses the fuel flow [230] as the fuel flow [230] passes by the flow splitter [180] and out of outlet [104].

18. The nozzle tip [100] of claim 17 wherein the first splitter plate [160] is positioned in a substantially vertical direction.

19. The nozzle tip [100] of claim 17 wherein the first splitter plate [160] is positioned in a substantially horizontal direction.

20. The nozzle tip of claim 17 wherein the flow splitter [180] is positioned between the inlet [102] and the outlet [104] and its base [481] is recessed with respect to the outlet [104].

12. A nozzle tip [100] for a pulverized solid fuel pipe nozzle [200] of a pulverized solid fuel-fired furnace that reduces NOx emissions, the nozzle tip [100] comprising:

a primary air shroud [120] having an inlet [102] and an outlet [104], wherein the inlet [102] receives a fuel flow [230];

a first splitter plate [160] disposed within the primary air shroud [120], the first splitter plate [160] and primary air shroud [120] defining a duct [260] for receiving a first portion of the fuel flow [230]; and

a second splitter plate [160] disposed within the primary air shroud [120], the second splitter plate [160] and primary air shroud [120] defining a duct [280] for receiving a second portion of the fuel flow [230], wherein the first splitter plate [160], the second splitter plate [160], and the primary air shroud [120] define a duct [270] for receiving a third portion of the fuel flow [230] disposed intermediate to the first portion and the second portion of the fuel flow [230], the third portion of the fuel flow [230] comprising a first split flow and a diverging second split flow, wherein

the first split flow and the first portion of the fuel flow [230] combine at the outlet [104] of the primary air shroud [120] to provide a first outlet fuel jet which exits the outlet [104] of the primary air shroud [120], and

the second split flow and the second portion of the fuel flow [230] combine at the outlet [104] of the primary air shroud [120] to provide a second outlet fuel jet which exits the outlet [104] of the primary air shroud [120] separate from the first outlet fuel jet.

13. The nozzle tip [100] of claim 12, wherein

the first outlet fuel jet and the second outlet fuel jet exit the outlet [104] of the primary air shroud [120] separate and discrete from each other, and

the first outlet fuel jet and the second outlet fuel jet remain separate and discrete from each other for a predetermined distance from the outlet [104] of the primary air shroud [120].

14. The nozzle tip [100] of claim 12, further comprising at least one of a shear bar [170] and a bluff point disposed on at least one of the first splitter plate [160] and the second splitter plate [160].

15. The nozzle tip [100] of claim 12, further comprising an air deflector [175] disposed on the first splitter plate [160].

16. The nozzle tip [100] of claim 13, wherein

the predetermined distance is in a range of approximately two (2) diameters of one of the first outlet fuel jet and the second outlet fuel jet to approximately eight (8) diameters of the one of the first outlet fuel jet and the second outlet fuel jet, and

the first outlet fuel jet and the second outlet fuel jet at least partially combine after traveling the predetermined distance from the outlet of the primary air shroud [120] [120] into the pulverized solid fuel-fired furnace.

21. The nozzle tip [100] of claim 12, further comprising:

a flow splitter [180] positioned between the flow splitter plates [160], the flow splitter [180] having a wedge shape with an apex edge [483] and a base [481], the apex edge [483] positioned closer to the inlet [102] and the base [481] positioned closer to the outlet [104], the flow splitter [180] extending only partially across the outlet [104], the flow splitter [180] creating turbulence in the fuel flow [230] that disperses the fuel flow [230] as the fuel flow [230] passes by the flow splitter [180] and out of outlet [104].

22. A nozzle tip [100] for a pulverized solid fuel pipe nozzle of a pulverized solid fuel-fired furnace that reduces NOx emissions, the nozzle tip [100] comprising:

a primary air shroud [120] having an inlet [102] and an outlet [104], wherein;

the inlet [102] receives solid fuel particles suspended in an airflow stream as a fuel flow,

the outlet [104] generally has a cross-sectional shape with a plurality of lobes [106] each radiating from a central location;

a flow splitter [180] disposed within the primary air shroud [120] substantially at the central location [108], the flow splitter [180] functioning to deflect solid particles of the fuel flow into each lobe [106] of the output [104] and disperse the particles within the lobes [106] allowing for combustion of the fuel flow with reduced NOx emissions.

23. The nozzle tip of claim 22 further comprising:

a splitter plate [160] disposed within the primary shroud [120] for supporting the flow splitter [180].