Method for reducing nitrogen oxide on the primary side in a two-stage combustion process
US8544394B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 18, 2007 |
| Grant date | Oct 1, 2013 |
| Priority date | — |
| Expiry date | Jul 5, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E20/34
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Method for reducing a formation of nitrogen oxide on a primary side of a furnace and reducing or avoiding nitrous oxide and ammonia slip in an offgas of the furnace in which a fuel is burned in a combustion process having at least two stages. The method includes passing a fuel consecutively through each of a plurality of bed areas of a combustion bed of the furnace. A primary gas including oxygen is fed individually to each of the bed areas so as to burn the fuel in the combustion chamber of the furnace. A secondary gas including oxygen is introduced into a downstream offgas burn-out zone, so as to after-burn incompletely burned offgas components formed during the burning of the fuel. Partial offgas streams from the combustion bed areas are axially mixed by injecting a water-gas mixture as at least one free jet above a surface of the combustion bed upstream from the downstream offgas burn-out zone so that the at least one free jet penetrates the partial offgas streams of the combustion bed areas to reduce a heating value of the offgas between the surface of the combustion bed and the downstream offgas burn-out zone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.