Ash Formation, Deposition, Corrosion, and Erosion in Conventional Boilers

  • Steven A. Benson
  • Edward N. Steadman
  • Christopher J. Zygarlicke
  • Thomas A. Erickson

Abstract

The inorganic components (ash-forming species) associated with coals significantly affect boiler design, efficiency of operation, and life span of boiler parts. During combustion in conventional pulverized fuel boilers, the inorganic components are transformed into inorganic gases, liquids, and solids. This partitioning depends upon the association of the inorganic components in the coal and upon combustion conditions. The inorganic components are associated as mineral grains and as organically associated elements, and these associations of inorganic components in the fuel directly influence their fate upon combustion. Combustion conditions, such as temperature and atmosphere, influence the volatility and the interaction of inorganic components during combustion and gas cooling, which influences the state, size, and composition distributions of the particulate and condensed ash species. The intermediate species are transported with the bulk gas flow through the combustion system, during which time the gases and entrained ash are cooled. Deposition, corrosion, and erosion occur when the ash intermediate species are transported to the heat-transfer surface, react with the surface, accumulate, sinter, and develop strength. Research over the past decade has significantly advanced understanding of ash formation, deposition, corrosion, and erosion mechanisms. Many of the advances in understanding and predicting ash-related issues can be attributed to the advanced analytical methods used to determine the inorganic composition of fuels and resulting ash materials. These new analytical techniques have been the key to elucidation of the mechanisms of ash formation and deposition. This information has been used to develop algorithms and computer models to predict the effects of ash on combustion system performance.

Keywords

Coal Particle Inorganic Component Combustion Condition Char Particle Pulverize Coal 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media New York 1996

Authors and Affiliations

  • Steven A. Benson
    • 1
  • Edward N. Steadman
    • 1
  • Christopher J. Zygarlicke
    • 1
  • Thomas A. Erickson
    • 1
  1. 1.Energy & Environmental Research CenterUniversity of North DakotaGrand ForksUSA

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