High velocity burner, system and method

A method for operating a high velocity furnace combustion chamber burner having an ignition chamber for discharging an ignited combustible mixture of primary air and fuel into the furnace combustion chamber, and at least one nozzle port for directing a high velocity stream of secondary air into the furnace combustion chamber in a direction generally parallel to the direction of flow from said ignition chamber, said method comprising the steps of:

• supplying fuel to the ignition chamber of the burner;
• supplying primary air to the burner during plural modes of burner operation including a first mode during which primary air alone is supplied to the burner ignition chamber up to a predetermined operational temperature of the chamber and a second mode above the predetermined operational temperature during which primary air is a minor percentage of air used for stoichiometric combustion of fuel supplied to said burner so as to introduce a low velocity stream into the combustion chamber;
• supplying secondary air in amounts constituting a major percentage of air required for stoichiometric combustion of fuel during said second mode;
• regulating said fuel supplying means so that fuel supply to said burner is supplied in desired amounts during said first mode and also in desired amounts during said second mode;
• and
• controlling the heating capacity of said burner at least during said second mode by intermittently terminating operation of said secondary air supplying means for variable periods of time.

A high velocity gas burner for a furnace combustion chamber, said burner comprising:

• a ceramic body defining a central burner ignition chamber converging to an accelerating nozzle and a plurality of secondary air accelerating nozzles surrounding and generally parallel to said first-mentioned accelerating nozzle;
• a fuel inlet tube opening to said burner ignition chamber;
• means defining a primary air distribution manifold about said fuel inlet tube and in fluid communication with said burner ignition chamber;
• means defining a secondary air distribution manifold in communication with said secondary air accelerating nozzles and surrounding said primary air distribution manifold;
• and
• means for supplying primary air to the burner for first and second modes of operation subsequent to burner start-up and for supplying secondary air to the burner for said second mode such that primary air alone is supplied to the ignition chamber up to a predetermined operational temperature of the combustion chamber in said first mode and thereafter, in said second mode when the combustion chamber exceeds the predetermined operational temperature, is a minor percentage of air used for stoichiometric combustion of fuel to introduce a low velocity stream of burning fuel into the furnace combustion chamber while secondary air constitutes a major percentage of air required for stoichiometric combustion of fuel whereby the production of NO.sub.x is minimized.