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US 5,472,339 AGranted
NOx reduction device
AssigneeLennox Industries Inc.
InventorsMark R. Rakowski, John W. Whitesitt, John H. Wiker
Life of this patent
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AssigneeLennox Industries Inc.
InventorsMark R. Rakowski, John W. Whitesitt, John H. Wiker
Estimating the term…
A device for inhibiting NOx production is disposed in a gas furnace combustion chamber. The device includes a baffle member for dividing the combustion chamber into first and second regions. A fuel-rich mixture of gas and primary combustion air is ignited by an inshot burner and the flame is drawn into the combustion chamber by an induced draft blower along with secondary combustion air. The combustion chamber is configured such that in the first region (i.e., upstream of the baffle member) turbulent mixing of the secondary combustion air with the flame is inhibited to maintain a relatively gas-rich flame. The baffle member channels the flame and secondary combustion air into a convergent flow path and the passage of the flame and secondary combustion air over the baffle member creates turbulence, which enhances mixing between the flame and secondary combustion air in the second region of the combustion chamber (i.e., downstream of the baffle member). The turbulent mixing effects substantially complete combustion of the gas/air mixture. Because the turbulent mixing occurs at a location farther along the flame path in the combustion chamber than in conventional gas furnaces, the flame temperature remains relatively low throughout the combustion chamber, thereby inhibiting NOx production.
In a gas furnace having an elongated combustion chamber with an inlet and an outlet, a burner for burning a combustible mixture of gas and primary combustion air to produce a relatively gas-rich flame spaced from and aligned with said inlet, and a blower for drawing the relatively gas-rich flame along with secondary combustion air at said inlet, into and through the combustion chamber, a device for lowering NOx emissions, said device comprising an elongated arm member of predetermined length, a bracket depending from one end of said arm member for mounting said device with a wall of the furnace and a baffle member ascending from an opposite end of said arm member at an obtuse angle with respect to a longitudinal axis of said and member, said device being located lengthwise in the combustion chamber with said bracket substantially coincident with the inlet, said longitudinal axis substantially parallel to an axis extending between the inlet and the outlet, and said baffle member located in the combustion chamber at a distance from the inlet substantially equal to said predetermined length.
In combination:
In combination:
Dependencies are inferred from the claim text.