Electrodynamic burner with a flame ionizer

Patent metadata

Field	Value
Publication number	US-9513006-B2
Application number	US-201314092911-A
Country	US
Kind code	B2
Filing date	Nov 27, 2013
Priority date	Nov 27, 2012
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

An ionizer provides charged particles to charge a combustion reaction. A conductive flame holder cooperates with the charged combustion reaction to hold the combustion reaction away from a fuel nozzle. Dilution and/or premixing of the fuel in the region between the fuel nozzle and the conductive flame holder results in a reduced flame temperature. The reduced flame temperature results in a reduced output of oxides of nitrogen (NOx).

First claim

What is claimed is:

1. An electrodynamic burner, comprising:
a fuel nozzle configured to provide fuel to support a combustion reaction;
an ionizer configured to generate charged particles, the ionizer being positioned away from the fuel nozzle and separated from contact with the combustion reaction by a charged particle transport path; and
a first electrode configured as a conductive flame holder positioned at a distance from the fuel nozzle to receive fuel from the fuel nozzle, the distance operating as a mixing zone to entrain air and/or flue gas into the fuel;
wherein the ionizer is configured to cause charged particles to flow along the transport path to electrically charge the combustion reaction;
wherein the electrical charge carried by the combustion reaction is configured to cooperate with the conductive flame holder to hold the combustion reaction proximate the conductive flame holder; and
wherein entrainment and dilution of the fuel reduces a combustion reaction temperature to reduce production of oxides of nitrogen (NOx) by the burner.

2. The electrodynamic burner of claim 1 , wherein the fuel nozzle is configured to provide fuel to flow past the flame holder at a velocity greater than a flame propagation velocity.

3. The electrodynamic burner of claim 1 , further comprising:
an electrode controller configured to control the ionizer.

4. The electrodynamic burner of claim 3 , wherein the electrode controller is configured to cause the ionizer to output a time-varying charge concentration.

5. The electrodynamic burner of claim 4 , wherein the time-varying charge concentration includes a periodically varying charge concentration.

6. The electrodynamic burner of claim 4 , wherein the time-varying charge concentration includes a time-varying polarity of charges.

7. The electrodynamic burner of claim 4 , wherein the time-varying charge concentration includes a periodicity having a frequency between about 200 and about 800 Hertz.

8. The electrodynamic burner of claim 7 , wherein the periodicity is characterized by a sinusoidal variation in charge concentration.

9. The electrodynamic burner of claim 7 , wherein the periodicity is characterized by a square wave variation in charge concentration.

10. The electrodynamic burner of claim 1 , wherein the flame holder is electrically isolated from ground and from voltages not carried by the charged particles.

11. The electrodynamic burner of claim 1 , wherein the fuel nozzle is conductive and electrically isolated from ground and from voltages not carried by the charged particles.

12. The electrodynamic burner of claim 1 , wherein the flame holder and the fuel nozzle are in electrical continuity with one another.

13. The electrodynamic burner of claim 1 , further comprising:
a plurality of flame holders disposed at two or more distances from the fuel nozzle.

14. The electrodynamic burner of claim 13 , further comprising:
a controller configured to switch electrical continuity between a holding voltage and the plurality of flame holders.

Assignees

• Clearsign Comb Corp

Inventors

• Krichtafovitch Igor A
• Wiklof Christopher A
• Colannino Joseph

Classifications

• F23D14/84

  Flame spreading or otherwise shaping (F23D14/70 takes precedence) · CPC title

• F23N5/00 Primary

  Systems for controlling combustion (regulating fuel supply F23N1/00, regulating air supply or draught F23N3/00) · CPC title

• F23C99/001

  Applying electric means or magnetism to combustion (for combustion engines F02B51/04, F02M27/04) · CPC title

• F23N5/12

  using ionisation-sensitive elements, i.e. flame rods · CPC title