Method for flame location transition from a start-up location to a perforated flame holder

Patent metadata

Field	Value
Publication number	US-9388981-B2
Application number	US-201514741153-A
Country	US
Kind code	B2
Filing date	Jun 16, 2015
Priority date	Feb 14, 2013
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

According to an embodiment, a combustion system is provided, which includes a nozzle configured to emit a diverging fuel flow, a flame holder positioned in the path of the fuel flow and that includes a plurality of apertures extending therethrough, and a preheat mechanism configured to heat the flame to a temperature exceeding a startup temperature threshold.

First claim

What is claimed is:

1. A method, comprising:
performing a burner startup procedure, including applying thermal energy to a primary flame holder by holding a flame supported by fuel emitted from a primary nozzle at a location between the primary nozzle and a side of the primary flame holder facing the primary nozzle;
terminating the burner startup procedure after a temperature of a portion of the primary flame holder is above a startup temperature threshold;
emitting a flow of fuel from the primary nozzle at an operational rate; and
supporting a flame within a plurality of apertures extending through the primary flame holder
wherein performing the burner startup procedure further includes generating turbulence in the fuel emitted from the primary nozzle by positioning a secondary flame holder between the primary nozzle and the primary flame holder; and
wherein terminating the burner startup procedure includes removing the secondary flame holder from between the primary nozzle and the primary flame holder.

2. A method, comprising:
performing a burner startup procedure, including applying thermal energy to a primary flame holder by holding a flame supported by fuel emitted from a primary nozzle at a location between the primary nozzle and a side of the primary flame holder facing the primary nozzle;
terminating the burner startup procedure after a temperature of a portion of the primary flame holder is above a startup temperature threshold;
emitting a flow of fuel from the primary nozzle at an operational rate; and
supporting a flame within a plurality of apertures extending through the primary flame holder;
wherein performing the burner startup procedure further includes holding the primary flame holder in a startup position and emitting a flow of fuel from the primary nozzle at a startup rate, the startup rate being sufficiently low as to enable a stable flame within the fuel flow, and wherein the terminating the burner startup procedure includes moving the primary flame holder from the startup position to an operational position.

3. The method of claim 1 , wherein terminating the burner startup procedure includes reducing a concentration of oxygen in a flow of oxidizer fluid.

4. The method of claim 1 , wherein terminating the burner startup procedure includes reducing a flame propagation speed in the flow of fuel.

5. A method, comprising:
performing a burner startup procedure, including applying thermal energy to a primary flame holder by holding a flame supported by fuel emitted from a primary nozzle at a location between the primary nozzle and a side of the primary flame holder facing the primary nozzle;
terminating the burner startup procedure after a temperature of a portion of the primary flame holder is above a startup temperature threshold;
emitting a flow of fuel from the primary nozzle at an operational rate; and
supporting a flame within a plurality of apertures extending through the primary flame holder;
wherein applying thermal energy to the primary flame holder includes applying an electrical potential across first and second electrodes positioned to apply electrical energy to the flame supported by the primary nozzle.

6. A method, comprising:
performing a burner startup procedure, including applying thermal energy to a primary flame holder by holding a flame supported by fuel emitted from a primary nozzle at a location between the primary nozzle and a side of the primary flame holder facing the primary nozzle;
terminating the burner startup procedure after a temperature of a portion of the primary flame holder is above a startup temperature threshold;
emitting a flow of fuel from the primary nozzle at an operational rate; and
supporting a flame within a plurality of apertures extending through the primary flame holder;
wherein applying thermal energy to the primary flame holder includes:
applying an electrical charge having a first polarity to the flame supported by the primary nozzle; and
holding a portion of the flame near the primary flame holder by applying a voltage having a second polarity, opposite the first polarity, to an electrode.

7. The method of claim 6 , wherein the electrode is positioned on a face of the primary flame holder.

8. The method of claim 7 , wherein the terminating the burner startup procedure includes retracting the electrode from a position between the primary nozzle and the primary flame holder.

9. A system, comprising:
an oxidant source configured to output air into a combustion volume;
a primary fuel nozzle configured to output fuel into the combustion volume;
a primary flame holder having:
an input face proximal to the primary fuel nozzle;
an output face distal from the primary fuel nozzle; and
a plurality of apertures extending between the input and output faces; and

a preheat mechanism configured to support a flame in a first position selected to preheat the primary flame holder, the preheat mechanism being configured to remove the flame from the first position after preheating the primary flame holder, the primary flame holder being configured to support a combustion reaction of the fuel and oxidant within the plurality of apertures after being preheated by the first flame;
wherein the first position is between the primary fuel nozzle and the primary flame holder; and
wherein the preheat mechanism includes an actuator coupled to the primary fuel nozzle and configured to move the fuel nozzle between a preheat position and an operating position.

10. The system of claim 9 , wherein the primary fuel nozzle outputs a preheat flow of the fuel for the flame in the first position when the primary fuel nozzle is in the preheat position and wherein the primary fuel nozzle outputs an operating flow of the fuel for the combustion reaction supported by the primary flame holder when the fuel nozzle is in the operating position.

11. A system, comprising:
an oxidant source configured to output air into a combustion volume;
a primary fuel nozzle configured to output fuel into the combustion volume;
a primary flame holder having:
an input face proximal to the primary fuel nozzle;
an output face distal from the primary fuel nozzle; and
a plurality of apertures extending between the input and output faces; and

a preheat mechanism configured to support a flame in a first position selected to preheat the primary flame holder, the preheat mechanism being configured to remove the flame from the first position after preheating the primary flame holder, the primary flame holder being configured to support a combustion reaction of the fuel and oxidant within the plurality of apertures after being preheated by the first flame;
wherein the first position is between the primary fuel nozzle and the primary flame holder
wherein the preheating mechanism includes a secondary flame holder configured to hold the flame in the first position.

12. The system of claim 11 , wherein the preheating mechanism is configured to support the flame in the first position by moving the secondary flame holder to a preheat position and to remove the flame from the first position by moving the secondary flame holder from the preheat position.

13. The system of claim 12 , wherein the preheating mechanism is configured to support the flame in the first position by applying a selected voltage between the flame and the secondary flame holder.

14. The system of claim 13 , wherein the preheating mechanism is configured to remove the flame from the first position by terminating the flame.

15. The system of claim 9 , wherein the preheating mechanism is configured to remove t

Assignees

• Clearsign Comb Corp

Inventors

• Karkow Douglas W
• Colannino Joseph
• Krichtafovitch Igor A
• Wiklof Christopher A

Classifications

• F23N2221/00

  Pretreatment or prehandling · CPC title

• F23N2227/22

  Pilot burners · CPC title

• F23D11/406

  Flame stabilising means, e.g. flame holders · CPC title

• F23D2207/00

  Ignition devices associated with burner · CPC title

• F23N5/10

  using thermocouples · CPC title