Low nox inter-tube burner for roof-fired furnaces
US5546874A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 22, 1994 |
| Grant date | Aug 20, 1996 |
| Priority date | — |
| Expiry date | Dec 22, 2014 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF23C2900/05081
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for reducing the formation of nitrogen oxides during combustion in a roof-fired furnace is disclosed. By blocking at least some of the fuel nozzles associated with a roof-fired burner while leaving open the secondary air openings associated with the blocked fuel nozzles, reduction in NOX emissions from roof-fired furnaces is accomplished. This blocking results in the creation of a localized fuel-rich or just slightly fuel-lean environment near open fuel nozzles because part of the secondary air needed for combustion is being added at a location distant from where the initial combustion occurs. By creating a localized fuel-rich or slightly fuel-lean environment near the open fuel nozzles, the initial stages of combustion occur with little or no excess oxygen present. Because much of the fuel-bound nitrogen is liberated during the initial stages of combustion, it will preferentially react to form molecular nitrogen rather than nitrogen oxides because of the lack of available oxygen. Further, by the time all the secondary air is mixed with the pulverized coal to complete substantially the combustion, the flame temperature will have been sufficiently lowered by h…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.