Method and apparatus for a dual mode burner yielding low nox emission

A method of operating a burner, comprising:

• activating an igniter;
• providing a fuel stream, a first air stream, and a secondary air stream to a combustion chamber of the burner;
• intermixing the fuel, first and secondary air streams to form a combustible mixture at a first flow rate, said combustible mixture being incapable of maintaining a stable flame within the combustion chamber;
• igniting the combustible mixture in the combustion chamber with the igniter;
• sensing a flame presence within the combustion chamber;
• maintaining the igniter active to sustain combustion of the combustible mixture within the combustion chamber;
• heating a space exterior to the combustion chamber to a temperature at or above an auto-ignition temperature of the combustible mixture;
• monitoring the temperature of the space exterior;
• providing the combustible mixture at a second flow rate, which is higher than the first flow rate, to extinguish a flame in the combustion chamber such that combustion occurs in the space exterior to the combustion chamber;
• and
• when combustion occurs in the space exterior to the combustion chamber, deactivating the igniter and discontinuing the secondary air stream.

A method for operating a burner, comprising:

• activating an igniter;
• providing a combustible mixture to a combustion chamber;
• sensing a flame presence in the combustion chamber;
• maintaining activation of the igniter to stabilize a flame in the combustible mixture within the combustion chamber;
• sensing an external temperature when a flame is sensed in the combustion chamber;
• comparing the external temperature with an auto-ignition temperature of the combustible mixture;
• and, when the external temperature is greater or equal than the auto-ignition temperature,
• transitioning the flame from the combustion chamber to an area external to the combustion chamber;
• and
• deactivating the igniter.