New Boiler Slag Issues Contunue
image credit: Photo by Rod Hatt in 2012, flame in the reheater
- Jul 27, 2020 4:15 pm GMT
- 298 views
Many of the new (post 2010) boilers are being designed and constructed are missing important coal combustion and slag control parameters. Many are trying to achieve so low of NOx using low NOx burners and over-fire air that they are moving the flame so high in the furnace that the increased temperatures are increasing slags and other ash deposits. Add to this a lack of appreciation of mill fineness and primary air flow and you add to the problems. Then the lack of observation door is very apparent with many utilities adding them post construction. Soot blowers are key and must be operated at pressures high enough to remove deposits, and often enough to keep up with rapid ash build-ups. Please keep in mind that some of the main causes of slag is poor fineness and lack of air, particularly with higher sulfur and iron (Fe2O3) coals.
Many of these issues are described in the following videos.
Here is a little on coal analyes.
Please let us know if you are having any slagging or fouling type ash deposits, maybe we can help you understand many of the issues.
Coal Combustion, Inc.