Fuel combustion system with a perforated reaction holder

Patent metadata

Field	Value
Publication number	US-9797595-B2
Application number	US-201414762155-A
Country	US
Kind code	B2
Filing date	Feb 14, 2014
Priority date	Feb 14, 2013
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A combustion system such as a furnace or boiler includes a perforated reaction holder configured to hold a combustion reaction that produces very low oxides of nitrogen (NOx).

First claim

What is claimed is:

1. A burner system, comprising:
a fuel and oxidant source disposed to output fuel and oxidant into a combustion volume to form a fuel and oxidant mixture; and
a perforated reaction holder disposed in the combustion volume, the perforated reaction holder including a perforated reaction holder body defining a plurality of perforations aligned to receive the fuel and oxidant mixture from the fuel and oxidant source;
wherein the perforations are configured to collectively hold a combustion reaction supported by the fuel and oxidant mixture;
wherein the plurality of perforations are each characterized by a transverse dimension D between opposing walls; and
wherein a length L of each perforation is at least eight times the transverse dimension D of the perforation.

2. The burner system of claim 1 , wherein the perforated reaction holder has a width dimension W RH between opposite sides of the peripheral surface at least one of: two times, three times, six times, and nine times, a thickness dimension T RH between the input surface and the output surface.

3. A burner system, comprising:
a fuel and oxidant source disposed to output fuel and oxidant into a combustion volume to form a fuel and oxidant mixture; and
a perforated reaction holder disposed in the combustion volume, the perforated reaction holder including a perforated reaction holder body defining a plurality of perforations aligned to receive the fuel and oxidant mixture from the fuel and oxidant source;
wherein the perforations are configured to collectively hold a combustion reaction supported by the fuel and oxidant mixture; and
further comprising a fuel nozzle configured to output fuel,
wherein the fuel nozzle is configured to emit the fuel through a fuel orifice having a dimension D O ; and
wherein the perforated reaction holder is disposed to receive the fuel and oxidant mixture at a distance D D away from the fuel nozzle greater than 20 times the fuel orifice dimension D O .

4. The burner system of claim 1 , wherein the perforated reaction holder body is configured to convey heat between adjacent perforations; and
wherein the heat conveyed between adjacent perforations is selected to cause heat output from the combustion reaction portion in a perforation to supply heat to stabilize a combustion reaction portion in an adjacent perforation.

5. The burner system of claim 1 ,
wherein a length L of each perforation is at least one of: eight times, twelve times, sixteen times, and twenty-four times, the transverse dimension D of the perforation.

6. The burner system of claim 1 , wherein the length L is sufficiently long for thermal boundary layers formed adjacent to the walls in a reaction fluid flowing through the perforations to converge within the perforations.

7. The burner system of claim 1 , wherein the perforations each have a lateral dimension D equal to or greater than a quenching distance of the fuel.

8. The burner system of claim 1 , wherein the perforations are non-parallel to one another.

9. The burner system of claim 1 , wherein the perforations are non-parallel to one another and non-intersecting.

10. The burner system of claim 1 , wherein the perforations are formed at an angle relative to an input surface and an output surface of the perforated reaction holder.

11. The burner system of claim 1 , wherein the perforations are respectively formed at an angle relative to an input and an output surface of the perforated reaction holder; and
wherein the perforations are collectively angled to produce a streamwise vortex in combustion fluid exiting from the perforated reaction holder.

12. The burner system of claim 1 , wherein the perforated reaction holder body is configured to receive heat from the fuel combustion reaction and output radiated heat energy to maintain a temperature of the perforated reaction holder body below an adiabatic flame temperature of the fuel combustion reaction.

13. The burner system of claim 1 , wherein the plurality of perforations comprise a plurality of elongated squares.

14. A burner system, comprising:
a fuel and oxidant source disposed to output fuel and oxidant into a combustion volume to form a fuel and oxidant mixture; and
a perforated reaction holder disposed in the combustion volume, the perforated reaction holder including a perforated reaction holder body defining a plurality of perforations aligned to receive the fuel and oxidant mixture from the fuel and oxidant source;
wherein the perforations are configured to collectively hold a combustion reaction supported by the fuel and oxidant mixture;
wherein the plurality of perforations are substantially normal to input and output surfaces of the perforated reaction holder, and
wherein the perforated reaction holder body defines a central aperture, a first set of apertures in a concentric arrangement relative to the central aperture having a selected spacing and size, and a second set of apertures in concentric arrangement relative to the central aperture having a different selected spacing and size; and
wherein the perforated reaction holder is configured to hold the fuel combustion reaction.

15. A burner system, comprising:
a fuel and oxidant source disposed to output fuel and oxidant into a combustion volume to form a fuel and oxidant mixture; and
a perforated reaction holder disposed in the combustion volume, the perforated reaction holder including a perforated reaction holder body defining a plurality of perforations aligned to receive the fuel and oxidant mixture from the fuel and oxidant source;
wherein the perforations are configured to collectively hold a combustion reaction supported by the fuel and oxidant mixture;
wherein the perforated flame holder body comprises fibers;
wherein the fibers comprise reticulated fibers; and
wherein the fibers define branching perforations that weave around and through the fibers.

16. A burner system, comprising:
a fuel and oxidant source disposed to output fuel and oxidant into a combustion volume to form a fuel and oxidant mixture; and
a perforated reaction holder disposed in the combustion volume, the perforated reaction holder including a perforated reaction holder body defining a plurality of perforations aligned to receive the fuel and oxidant mixture from the fuel and oxidant source;
wherein the perforations are configured to collectively hold a combustion reaction supported by the fuel and oxidant mixture;
wherein the perforated reaction holder body is continuous; and
wherein the perforated reaction holder body defines perforations that branch from one another.

17. A burner system, comprising:
a fuel and oxidant source disposed to output fuel and oxidant into a combustion volume to form a fuel and oxidant mixture; and
a perforated reaction holder disposed in the combustion volume, the perforated reaction holder including a perforated reaction holder body defining a plurality of perforations aligned to receive the fuel and oxidant mixture from the fuel and oxidant source;
wherein the perforations are configured to collectively hold a combustion reaction supported by the fuel and oxidant mixture;
wherein the perforated reaction holder body comprises a plurality of pillars; and
wherein the plurality of perforations comprise spaces between the plurality of pillars.

18. The burner system of claim 17 , further comprising:
a base plate operatively coupled to the plurality of pillars, and
wherein the base plate defines a plurality of apertures configured to allow oxidation fluid to flow into

Assignees

• Clearsign Comb Corp

Inventors

• Karkow Douglas W
• Breidenthal Robert E
• Colannino Joseph
• Wiklof Christopher A

Classifications

• F23N2227/22

  Pilot burners · CPC title

• F23N2221/00

  Pretreatment or prehandling · CPC title

• F23D14/26 Primary

  with provision for a retention flame (pilot flame igniters F23Q9/00) · CPC title

• F23D11/448

  heated by electrical means · CPC title

• F23N5/10

  using thermocouples · CPC title