Low NOx Burner

Low NOx burner is how to get perfect combustion so fuel/air ratio plus excess air is not so much air into combustion chamber because air is content 76.8% of nitrogen (just only 23.2% of oxygen), so too much air is very potential for NOx produce. 2% of oxygen on flue gas is possible to application.

The Hitachi Ltd. Group is acutely aware of the need to respond to global environmental issues and therefore dedicates great deal of continuous professional research effort to realize improvements to its various product lines.

For pulverized coal combustion we firstly developed a unique Low-NOx burner system, the HT-NR burner, based on the concept of "In-flame NOx reduction".This sophisticated and proven reliable design, together with recognition within the Industry of Hitachi's continuous contribution to Low NOx combustion technology, merited the prestigious Award of the JSME Medal (Japan Society of Mechanical Engineers) and the Premier Prize from the Director-General of the Environmental Agency.Continuation of research effort by Hitachi lead to development of a second-generation Low-NOx burner, designated HT-NR2, with further enhanced NOx decomposition capability.The widely acclaimed HT-NR2 burner has proven extremely reliable and has many applications in both the domestic and foreign industrial and power boiler markets.

Ongoing development work by Hitachi resulted in the introduction of a third generation Low-NOx burner, designated HT-NR3, featuring further reduced NOx emission levels, improved combustion efficiency and ease of maintenance, developed through design simplification application. This latest design utilizes a wider and shorter, highly stable flame for excellent fuel combustion characteristics with extremely Low NOx levels.

The advanced performance characteristics of this latest generation Hitachi burner has been confirmed by installation and testing in power boiler plants offering state of the art burner combustion technology coupled with extremely high plant reliability and operational availability.Hitachi can custom design and built plant to provide the optimal solution for your specific power requirements.


Feature and History
1. Rapid ignition with Flame Stabilizing Ring (US Patent No.4,545,307 Dated Oct 8,85).

2. Effective separation of outer air to produce reducing conditions in the center zone.
3. PC concentration for higher combustion efficiency in reducing condition
Enhancement of the above features was achieved by the development indicated.

Concept of In-Frame NOx
Reduction



Comparison of Flames
Stable and brilliant flames are established from the edges of the burners. A wider and shorter flame is obtained in the HT-NR3 design, which realizes extremely Low NOx and high combustion efficiency.

Typical NOx Emission Level achieved by NR3 Design

Information about Boiler Axial Fan Stall, click below this ....
http://idpowerstation.blogspot.com/2009/06/fan-stall.html