US3832122A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reduction of nitrogen oxides from products of hydrocarbon combustion with air
Assignee: Aqua Chem Inc
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Filing: 1972-01-06
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Granted: 1974-08-27
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Expires: 1992-01-06
Abstract
Abstract Fuel is burned in a primary combustion zone so that a substantial quantity of unburned hydrocarbons, such as carbon monoxide (CO) is produced along with some nitrogen oxides (NOx) and whereby essentially no oxygen remains at the completion of the combustion process. The gaseous combustion products are conducted through a gas dispersion matrix or bed in which the unburned hydrocarbons and NOx react to produce carbon dioxide (CO2) and nitrogen (N2). Air is then injected into the gases in a secondary combustion zone to oxidize the residual unburned hydrocarbons to CO2 in which case the exhaust gases are substantially free of air polluting CO and NOx.
Inventors
- 👤 Haye P La
- 👤 G Craig
- 👤 J Turecek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:22
CPC Classifications
F; F23; F23C; F23C13/00; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/54; B01D53/56; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; B01D53/8631; F23B; F23B5/00; F23C6/00; F23C6/04; F23J; F23J15/00; F24; F24H; F24H9/00; F24H9/18; F24H9/1809; F24H9/1832; F24H9/1845; F23B2700/00; F23B2700/018; F24H1/00; F24H1/0027; F24H1/0045; Y; Y02; Y02A; Y02A50/00; Y02A50/20
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
22 words
The invention set forth in claim 1 and including means for maintaining the temperature in said secondary combustion zone below about 2700*F.
Claim 2
Dependent Claim
53 words
The invention set forth in claim 2 wherein said enclosure also includes a gas dispersion means between said first combustion zone and said second combustion zone, said gas dispersion means being arranged so that the combustion products emitted from said first combustion zone pass therethrough before being received in said second combustion zone.
Claim 3
Dependent Claim
18 words
The invention set forth in claim 3 wherein: a. said gas dispersion means comprises a porous, refractory matrix.
Claim 4
Dependent Claim
27 words
The invention set forth in claim 4 wherein: a. said matrix includes a catalyst for promoting the reaction of nitrogen oxides with unburned hydrocarbon and carbonaceous materials.
Claim 5
Dependent Claim
21 words
The invention set forth in claim 4 wherein: a. said refractory material matrix comprises silicon carbide fragments forming a porous bed.
Claim 6
Dependent Claim
20 words
The invention set forth in claim 3 wherein: a. said gas pervious tube means comprise porous tubes of refractory material.
Claim 7
Dependent Claim
20 words
The invention set forth in claim 3 wherein: a. said gas dispersion means comprises a porous layer of catalytic material.
Claim 8
Dependent Claim
31 words
The invention set forth in claim 3 wherein: a. said dispersion means comprises a metallic element selected from the group consisting of iron, nickel, chromium, copper and platinum and alloys thereof.
Claim 9
Dependent Claim
44 words
The invention set forth in claim 1 wherein said gas pervious tube means includes at least one hollow tube disposed in said second zone and having plural, spaced apart gas permeable means formed in said hollow tube for permitting the flow of gas therethrough.
Claim 10
Dependent Claim
20 words
The invention set forth in claim 10 wherein said gas pervious tube means has a plurality of apertures formed therein.
Claim 11
Dependent Claim
44 words
The device set forth in claim 1 and including heat absorbing means located in said enclosure downstream from said second combustion zone for absorbing heat from said second combustion zone and for maintaining the temperature in said second combustion zone below a predetermined level.
Claim 12
Independent Claim
90 words
The method of reducing nitrogen oxides in exhaust gases comprising: providing a primary combustion zone, incompletely oxidizing a fuel in said primary combustion zone to provide gaseous combustion products including unburned hydrocarbOns, passing said gases through a second combustion zone, introducing a source of oxygen into said secondary combustion zone whereby to oxidize the residual unburned hydrocarbons in said stream before discharge thereof, maintaining the temperature in said secondary combustion zone at less than 2700*F, said unburned hydrocarbon comprises carbon monoxide having concentration in excess of 400 parts per million.
Claim 13
Dependent Claim
104 words
A combustion device adapted for reducing nitrogen oxides in its exhaust gas, comprising: a. an enclosure having fuel burning means and an outlet, b. a first combustion zone in said enclosure wherein fuel is burned with incomplete oxidation to produce combustible products including unburned hydrocarbons and including gas dispersion means through which said gaseous combustion products are conducted, c. a second combustion zone including porous silicon carbide tube means for introducing oxygen into said gaseous combustion products whereby to oxidize residual combustion products including unburned hydrocarbons therein before discharge, and d. means for maintaining the temperature in said secondary combustion zone below about 2700*F.
Claim 14
Dependent Claim
114 words
A combustion device adapted for reducing nitrogen oxides in its exhaust gas, comprising: means defining a first combustion zone, first means for introducing fuel and less than the amount of oxygen and nitrogen containing gas required for complete combustion wherein fuel is burned with incomplete oxidation to produce combustible products including unburned carbonaceous materials, means defining a second combustion zone, means for conducting said combustible products to said second combustion zone, said second combustion zone including plural tube means extending into said zone, said tube means being constructed and arranged to supply air to plural zones within said second combustion zone whereby to oxidize residual combustible products including unburned carbonaceous materials therein before discharge.
Claim 15
Dependent Claim
46 words
The combustion device set forth in claim 15 wherein said tube means extends generally transversely to the direction of gas flow in said secondary zone whereby said gases from said primary zone are forced to flow around said tube means to promote mixing with said air.
Claim 16
Dependent Claim
28 words
The invention set forth in claim 16 and including a common manifold connected to at least one end of each of said tube means for delivering air thereto.
Claim 17
Dependent Claim
17 words
The invention set forth in claim 17 and said tube means are formed of silicon carbide material.
Claim 18
Dependent Claim
13 words
The invention set forth in claim 18 wherein said tube means are porous.
Claim 19
Dependent Claim
20 words
The invention set forth in claim 19 wherein each of said tube means has a plurality of apertures formed therein.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |