US 5,546,925 A · Inshot fuel burner Nox reduction device with integral positioning support structure

Abstract

A fuel fired, forced air, draft induced heating furnace is provided with NOx reduction apparatus associated with a plurality of combustor tubes forming a portion of its heat exchanger structure. In-shot type fuel burners are spaced apart from and face the open inlet ends of horizontal combustion sections of the combustor tubes. The NOx reduction apparatus includes a plurality of insert members received in inlet end portions of the combustor tubes. Each insert member is formed from a single sheet of metal mesh material and has a hollow, open-ended body portion coaxially received in its associated combustor tube and spaced laterally inwardly from its interior side surface, and a circumferentially spaced plurality of integral, laterally outwardly projecting support rib portions that slidably engage the interior side surface of the combustor tube, thereby automatically maintaining the insert member in a coaxial relationship with the combustor tube regardless of the positional orientation of the tube. To axially retain the insert within the combustor tube, an end portion of one of the centering ribs has a lateral notch that receives a rod anchored to and extending transversely across the inlet end portion of the combustor tube.

Claims27

Dependent claims

A reduced NOx emission combustion system for a fuel-fired heating appliance, comprising:

a combustor tube having an open inlet end and an essentially straight combustion section longitudinally extending inwardly from said open inlet end and having an interior side surface;
a fuel burner operative to inject a flame and resulting hot combustion gases into said open inlet end for flow through said combustion section of said combustor tube in a manner drawing ambient combustion air into said combustion section around the flame;
and
apparatus for reducing the NOx emissions of the heating appliance during operation thereof, said apparatus including:
a NOx reducing insert member formed from a metal mesh material and having a hollow body portion extending lengthwise along an axis and opposite open ends longitudinally spaced apart along said axis, and a circumferentially spaced plurality of axially elongated ribs projecting laterally outwardly from said body portion, said NOx reducing insert member being received within said combustion section of said combustor tube with said ribs slidably engaging said interior side surface of said combustion section and maintaining said body portion in a coaxial, laterally inwardly spaced relationship with said combustion section, each of said ribs being defined by a different side-by-side duality of circumferential segments of said body portion secured to one another in a parallel, abutting relationship, and
cooperatively engaged means on said combustion section and said NOx reducing insert member for preventing appreciable axial movement of said NOx reducing insert member within said combustion section.

3 more elements

A fuel fired forced air heating furnace comprising:

a housing;
a supply air blower operative to flow air to be heated through said housing;
a heat exchanger, interposed in the supply air blower air flow path, for transferring combustion heat to the air being flowed through said housing, said heat exchanger including a plurality of combustor tubes each having an open inlet end, an interior side surface, and an outlet end;
a plurality of in-shot type fuel burners disposed in facing orientations with said open inlet ends of said combustor tubes and operative to inject flames and resulting hot combustion gases thereinto in a manner drawing ambient combustion air into said open inlet ends of said combustor tubes around the flames traversing the interiors thereof;
a draft inducer fan having an inlet communicated with said outlet ends of said combustor tubes, said draft inducer fan being operative to draw hot combustion gases through said combustor tubes;
and
NOx reduction apparatus for reducing the NOx emission rate of said furnace, said NOx reduction apparatus including:
a plurality of NOx reducing insert members each formed from a metal mesh material and having a hollow body portion extending lengthwise along an axis and opposite open ends longitudinally spaced apart along said axis, and a circumferentially spaced plurality of axially elongated ribs projecting laterally outwardly from said body portion, said NOx reducing insert members being received within inlet end portions of said combustor tubes, with said ribs slidably engaging said interior side surfaces of said inlet end portions and maintaining said body portions in coaxial, laterally inwardly spaced relationships with their associated inlet end portions of said combustor tubes, each of said ribs being defined by a different side-by-side duality of circumferential segments of said body portion secured together in a parallel, abutting relationship, and
cooperatively engaged means on said inlet end portions of said combustor tubes and said NOx reducing insert members for preventing appreciable axial movement of said NOx reducing members relative to their associated inlet end portions of said combustor tubes.

6 more elements

Dependencies are inferred from the claim text.

Inshot fuel burner Nox reduction device with integral positioning support structure

Life of this patent

Inshot fuel burner Nox reduction device with integral positioning support structure

Life of this patent

Abstract

Claims27