Inner furnace air chamber

Claim 1

A furnace assembly comprising a housing formed by a plurality of interconnected walls, a plurality of burners associated with at least one of said walls, means for supplying an air-fuel mixture to said burners for combusting in said housing, an enclosure extending within said housing and formed by interconnected walls, a wall of said enclosure extending parallel to said one wall of said housing and having a plurality of openings respectively facing said burners, said latter enclosure wall being formed by a plurality of interconnected finned tubes, and means for supplying air to said enclosure for discharging through said openings and towards said burners for mixing and combusting with the unburnt fuel from said burners, and means for passing water through said tubes to cool said tubes and the air discharging through said openings.

Claim 5

A method of burning a fUel-air mixture in a furnace to produce a minimum amount of nitrogen oxides in the combustion gases leaving the furnace, which comprises the steps of introducing the fuel into the furnace through a burner port in a furnace wall, introducing a portion of the combustion air into said furnace through said burner port in mixing relationship with said fuel, regulating the amount of air supplied through said burner port to an amount which is less than the theoretical combustion air requirements for the corresponding fuel to delay the complete combustion of said fuel and thereby reduce the maximum flame temperature in the furnace and the formation of nitrogen oxides below the values which would occur if all of the air required for complete combustion were introduced with the fuel, discharging the remaining amount of air required to insure complete combustion of the fuel through openings extending through a wall of an enclosure disposed within said furnace, said remaining amount of air being directed towards said burner port and in a direction opposite the direction of discharge of said fuel and air so as to mix said remaining amount of air with the unburnt portion of said fuel to complete the combustion of said fuel, and cooling the wall of said enclosure through which said openings extend to cool said remaining amount of air.

Claim 6

A method of burning a fUel-air mixture in a furnace to produce a minimum amount of nitrogen oxides in the combustion gases leaving the furnace, which comprises the steps of introducing the fuel into the furnace through a burner port in a furnace wall, introducing a portion of the combustion air into said furnace through said burner port in mixing relationship with said fuel, regulating the amount of air supplied through said burner port to an amount which is less than the theoretical combustion air requirements for the corresponding fuel to delay the complete combustion of said fuel and thereby reduce the maximum flame temperature in the furnace and the formation of nitrogen oxides below the values which would occur if all of the air required for complete combustion were introduced with the fuel, discharging the remaining amount of air required to insure complete combustion of the fuel through openings extending through a wall of an enclosure disposed within said furnace, said remaining amount of air being directed towards said burner port and in a direction opposite the direction of discharge of said fuel and air so as to mix said remaining amount of air with the unburnt portion of said fuel to complete the combustion of said fuel, and cooling the wall of said enclosure through which said openings extend to cool said remaining amount of air.