Oxygen-fuel burner with adjustable flame characteristics

An oxy-fuel burner for producing a long, luminous flame, the burner comprising:

• a fuel conduit having a nozzle end;
• a primary oxidant conduit having a nozzle end positioned below the fuel conduit;
• a secondary oxidant conduit having a nozzle end positioned above the fuel conduit;
• a fuel delivery system for delivering the fuel to the fuel conduit at a pressure which causes the fuel to exit the fuel nozzle end at a first velocity;
• a primary oxidant delivery system for delivering the primary oxidant to the primary oxidant conduit at a pressure which causes the primary oxidant to exit the primary oxidant nozzle end at a second velocity;
• a secondary oxidant delivery system for delivering the secondary oxidant to the secondary oxidant conduit at a pressure which causes the secondary oxidant to exit the second oxidant nozzle end at a third velocity, wherein the second velocity is greater than the first and third velocities.

A method of generating a flame suitable for float glass furnaces, the method comprising:

• injecting a fuel through a centrally located nozzle in a refractory burner block;
• injecting a primary oxidant at supersonic velocity below the fuel;
• and
• injecting a secondary oxidant above the fuel nozzle at a lower velocity than the primary oxidant.

A method of generating a long, luminous flame, the method comprising:

• injecting a fuel through a centrally located nozzle in a refractory burner block;
• injecting a primary oxidant containing at least 50% oxygen below the fuel at a first velocity;
• and
• injecting a secondary oxidant containing less than 30% oxygen above the fuel at a second velocity which is less than the first velocity.