Down-fired burner with a perforated flame holder

A down-fired burner, comprising:

• a down-fired fuel nozzle configured to output fuel in a downward direction;
• an oxidant source configured to output an oxidant;
• a flame holder positioned below the down-fired fuel nozzle, the flame holder including:
• an input surface facing the down-fired fuel nozzle;
• an output surface opposite the fuel nozzle;
• and
• a plurality of perforations extending from the input surface to the output surface and collectively configured to promote a combustion reaction of the fuel and oxidant within the perforations;
• and
• a preheating mechanism configured to heat the flame holder prior to starting the combustion reaction.

A down-fired burner, comprising:

• a down-fired fuel nozzle configured to output fuel in a downward direction;
• an oxidant source configured to output an oxidant;
• a flame holder positioned below the down-fired fuel nozzle, the flame holder including:
• an input surface facing the down-fired fuel nozzle;
• an output surface opposite the fuel nozzle;
• and
• a plurality of perforations extending from the input surface to the output surface and collectively configured to promote a combustion reaction of the fuel and oxidant within the perforations;
• and
• a tube extending vertically adjacent to the flame holder and containing a catalyst.

A method comprising:

• heating a flame holder positioned within a combustion volume and having a plurality of perforations each extending from a top surface of the flame holder to a bottom surface of the flame holder, wherein the flame holder is of a refractory material;
• outputting fuel from a first nozzle in a downward direction onto a top surface of the flame holder;
• introducing an oxidant into the combustion volume;
• igniting a combustion reaction of the fuel and oxidant in the plurality of perforations;
• and
• containing the combustion reaction of the fuel and oxidant substantially in the perforations in the flame holder.

A method, comprising:

• heating a flame holder positioned within a combustion volume and having a plurality of perforations each extending from a top surface of the flame holder to a bottom surface of the flame holder;
• outputting fuel from a first nozzle in a downward direction onto a top surface of the flame holder;
• introducing an oxidant into the combustion volume;
• igniting a combustion reaction of the fuel and oxidant in the plurality of perforations;
• containing the combustion reaction of the fuel and oxidant substantially in the perforations in the flame holder;
• passing a reactant through a reactor tube positioned adjacent to the flame holder;
• and
• causing a reaction between the reactant and a catalyst in the tube by radiating heat onto the tube from the flame holder.

A method, comprising:

• heating a flame holder positioned within a combustion volume and having a plurality of perforations each extending from a top surface of the flame holder to a bottom surface of the flame holder;
• outputting fuel from a first nozzle in a downward direction onto a top surface of the flame holder;
• introducing an oxidant into the combustion volume;
• igniting a combustion reaction of the fuel and oxidant in the plurality of perforations;
• and
• containing the combustion reaction of the fuel and oxidant substantially in the perforations in the flame holder, wherein the combustion reaction is a reaction of the fuel with oxygen.

A system comprising:

• a plurality of downward facing fuel nozzles each of which is configured to output a fuel in a downward direction;
• one or more oxidant sources configured to output oxidant;
• a plurality of flame holders each of which is positioned below a respective downward facing fuel nozzle, each flame holder including:
• a top surface;
• a bottom surface;
• and
• a plurality of perforations between the top and bottom surfaces, the flame holders being configured to confine a majority of a combustion reaction of the fuel and oxidant within the perforations, wherein the flame holder is of a refractory material;
• and
• a plurality of tubes, each of which is positioned adjacent to a respective flame holder and to output a reaction product of a reaction between a reactant and a catalyst within the tube.

A system, comprising:

• a plurality of downward facing fuel nozzles each of which is configured to output a fuel in a downward direction;
• one or more oxidant sources configured to output oxidant;
• a plurality of flame holders each of which is positioned below a respective downward facing fuel nozzle, each flame holder including:
• a top surface;
• a bottom surface;
• and
• a plurality of perforations between the top and bottom surfaces, the flame holders being configured to confine a majority of a combustion reaction of the fuel and oxidant within the perforations;
• a plurality of tubes, each of which is positioned adjacent to a respective flame holder and to output a reaction product of a reaction between a reactant and a catalyst within the tube;
• and
• a plurality of preheating mechanisms each positioned adjacent to a respective flame holder and configured to preheat the respective flame holder to a threshold temperature prior to outputting the fuel from the respective fuel nozzle.