Compact low NOx gas burner apparatus and methods

A compact gas burner apparatus having a folded flame pattern, a short flame length and a high turndown ratio for discharging a mixture of fuel gas and air into a furnace space wherein the mixture is burned and flue gases having low NOx content are formed therefrom comprising:

• a housing having an open end attached to said furnace space;
• an air register for introducing a controlled flow rate of air into said housing attached thereto;
• a burner tile attached to the open end of said housing having an opening formed therein for allowing said air to flow therethrough and having a wall surrounding said opening which extends into said furnace space, the exterior sides of said wall being divided into sections by a plurality of radially positioned baffles attached thereto with alternate sections having the same or different heights and slanting towards said opening at the same or different angles, a first of said alternating wall sections having a short height and slanting towards said opening at a large angle, the second of said wall sections having the same or a taller height and slanting towards said opening at the same or a smaller angle and successive alternating sections having heights and angles which are the same as said first and second sections, every other of said slanted wall sections also having a passageway formed therein for conducting primary fuel gas and flue gases into the interior of said wall;
• and
• a plurality of fuel gas nozzles connected to a source of fuel gas and positioned outside said wall of said burner tile said fuel gas nozzles positioned adjacent to said external slanted wall sections having a primary fuel gas passageway formed therein discharge primary fuel gas into said passageway said fuel gas nozzles being positioned in a manner such that the discharge of fuel gas draws flue gases into said primary fuel gas passageway and said fuel gas nozzles also discharge secondary fuel gas along said slanted wall having a primary fuel gas passageway formed therein whereby said secondary fuel gas mixes with flue gases in said furnace space said nozzles positioned adjacent to sections lacking a primary fuel gas passageway discharge secondary fuel gas adjacent to said slanted wall sections whereby said secondary fuel gas mixes with flue gases in said furnace space.

A compact gas burner apparatus having a short flame length and a high turndown ratio for discharging a mixture of fuel gas and air into a furnace space wherein the mixture is burned and flue gases having low NOx content are formed therefrom comprising:

• a housing having an open end attached to said furnace space;
• means for introducing a controlled flow rate of said air into said housing attached thereto;
• a burner tile attached to the open end of said housing having an opening formed therein for allowing said air to flow therethrough and having a wall surrounding said opening which extends into said furnace space, the exterior sides of said wall being divided into sections by a plurality of radially positioned baffles attached thereto, wherein every other section is slanted at a first angle and a second angle towards said opening, and wherein at least one section slanted at a first angle has a primary fuel gas passageway formed therein for conducting primary fuel gas and flue gases from outside said section to within said wall;
• said sections slanted at a second angle do not have a primary fuel gas passageway therein;
• and
• a plurality of fuel gas nozzles connected to a source of fuel gas and positioned outside said wall of said burner tile;
• at least one fuel gas nozzle connected to said source of fuel gas is positioned adjacent to at least one section slanted at a second angle, said fuel gas nozzle discharges secondary fuel gas along said exterior of said wall section slanted at a second angle whereby said secondary fuel gas mixes with flue gases in said furnace space;
• at least one fuel gas nozzle connected to said source of fuel gas is positioned adjacent to at least one section slanted at a first angle, said fuel gas nozzle discharges primary fuel gas into at least one primary fuel gas passageway and discharges secondary fuel gas along said exterior of said wall section slanted at a first angle whereby said secondary fuel gas mixes with flue gases in said furnace space.