US3918834A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of reducing the concentration of nitrogen oxides in a gaseous effluent from a thermal plant
Assignee: Individual
•
Filing: 1973-08-09
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Granted: 1975-11-11
•
Expires: 1993-08-09
Abstract
Abstract A method of reducing the concentration of nitrogen oxides in a gaseous effluent from a thermal plant fitted with burners, consisting in the burning of the fuel in two stages under the conditions of oxygen deficiency in a high-temperature zone, the two-stage combustion being accomplished by redistributing the flows of fuel and air inside the burners so that some air mixed with fuel is introduced in a spiral flow at periphery of the passages through the burners, and the rest of the air required for complete combustion of the fuel being introduced in a straight-line flow directed along the axis of the burners.
Inventors
- 👤 Isaak Yakovlevich Sigal
- 👤 Georgy Fedorovich Naidenov
- 👤 Sergei Savatievich Nizhnik
- 👤 Nikolai Alexandrovich Gurevich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:49
CPC Classifications
F; F23; F23D; F23D14/00; F23D14/20; F23B; F23B5/00; F23C; F23C7/00; F23C7/002; F23B2700/00; F23B2700/018
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
190 words
A METHOD OF REDUCING THE CONCENTRATION OF NITROGEN OXIDES IN A GASOUS EFFLUENT OF THE COMBUSTION IN A THERMAL PLANT FILLED WITH BURNERS HAVING AXIAL PASSAGES, THE METHOD COMPRISING THE STEPS OF BURNING A FUEL IN TWO STAGES WITHIN THE SAME HEAT-RECEIVING CHAMBER OF THE THERMAL PLANT, UNDER THE CONDITIONS OF OXYGEN DEFICIENCY IN A HIGH TEMPERATURE ZONE THE TWO-STAGE COMBUSTION BEING ACCOMPLISHED BY REDISTRIBUTING THE FLOW OF THE FUEL AND AIR INSIDE THE BURNERS SO THAT PART OF THE AIR IS INTRODUCED IN A FIRST, SPIRAL AT THE PERIPHERY OF THE PASSAGES OF THE BURNERS, AND INTRODUCING THE REST OF THE AIR, REQUIRED FOR COMPLETE COMBUSTION OF THE FUEL, IN A SECOND STRAIGHT-LINE FLOW DIRECTED ALONG THE AXIS OF THE BURNERS, ALL OF THE FUEL BEING INTRODUCED IN A PERIPHERAL ZONE SURROUNDING THE AXIAL PASSAGES, TOGETHER WITH THE FIRST AIR FLOW, WITH WHICH ALL FUEL IS INTERMIXED, THEREYCAUSING A CONE-SHAPED FLAME TO EMERGE FROM THE PERIPHERAL ZNE CONSTITUTING A FIRST, HIGHTEMPERATURE COMBUSTION STAGE, WHILE THE SECOND AIR FLOW CONTRIBUTES TO A SECOND LOWER-TEMPERATURE COMBUSTION STAGE AXIALLY LOCATED WITH RESPECT TO BUT SPACED AT A DISTANCE FROM THE FIRST STAGE.
Claim 2
Independent Claim
190 words
A METHOD OF REDUCING THE CONCENTRATION OF NITROGEN OXIDES IN A GASOUS EFFLUENT OF THE COMBUSTION IN A THERMAL PLANT FILLED WITH BURNERS HAVING AXIAL PASSAGES, THE METHOD COMPRISING THE STEPS OF BURNING A FUEL IN TWO STAGES WITHIN THE SAME HEAT-RECEIVING CHAMBER OF THE THERMAL PLANT, UNDER THE CONDITIONS OF OXYGEN DEFICIENCY IN A HIGH TEMPERATURE ZONE THE TWO-STAGE COMBUSTION BEING ACCOMPLISHED BY REDISTRIBUTING THE FLOW OF THE FUEL AND AIR INSIDE THE BURNERS SO THAT PART OF THE AIR IS INTRODUCED IN A FIRST, SPIRAL AT THE PERIPHERY OF THE PASSAGES OF THE BURNERS, AND INTRODUCING THE REST OF THE AIR, REQUIRED FOR COMPLETE COMBUSTION OF THE FUEL, IN A SECOND STRAIGHT-LINE FLOW DIRECTED ALONG THE AXIS OF THE BURNERS, ALL OF THE FUEL BEING INTRODUCED IN A PERIPHERAL ZONE SURROUNDING THE AXIAL PASSAGES, TOGETHER WITH THE FIRST AIR FLOW, WITH WHICH ALL FUEL IS INTERMIXED, THEREYCAUSING A CONE-SHAPED FLAME TO EMERGE FROM THE PERIPHERAL ZNE CONSTITUTING A FIRST, HIGHTEMPERATURE COMBUSTION STAGE, WHILE THE SECOND AIR FLOW CONTRIBUTES TO A SECOND LOWER-TEMPERATURE COMBUSTION STAGE AXIALLY LOCATED WITH RESPECT TO BUT SPACED AT A DISTANCE FROM THE FIRST STAGE.
Claim 3
Dependent Claim
52 words
The method as defined in claim 1, wherein the amount of air allotted to the first, spiral flow is between 40 to 70 per cent of the total air supply while the amount of air constituting the rest, for the second, straight-line flow is 60 to 30 per cent of the supply.
References Cited (Backward Citations)
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US3266549A
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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) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |