Analytical solution for steady and unsteady state particle size distribution in FBC and CFBC boilers for non-breaking char particles

Jaakko Saastamoinen (Corresponding Author), Antti Tourunen, Jouni Hämäläinen, T. Hyppänen, M. Loschkin, A. Kettunen

Research output: Contribution to journalArticleScientificpeer-review

11 Citations (Scopus)


Continuous analytical solutions for the particle size distributions of char in steady and unsteady states in fluidized beds, when the inlet fuel feed is presented by monosize, lognormal, Rosin-Rammler or gamma distributions, are derived from a population balance model. The stationary size distribution is directly related to the rate of reduction of the particle size. Combustion and attrition reduce the particle size. Thus, it is possible to extract the dependence of the rate of reduction of radius (affected by a fuel’s reactivity and attrition) on radius from a measured steady-state particle size distribution. Unsteady particle size distributions are derived for impulse, step and square pulse changes in the fuel feed, when the oxygen level in the reactor is maintained constant.
Original languageEnglish
Pages (from-to)395-405
Number of pages11
JournalCombustion and Flame
Issue number3
Publication statusPublished - 2003
MoE publication typeA1 Journal article-refereed



  • particle size distribution
  • fluidized bed combustion
  • population balance modelling
  • char
  • particle size
  • emissions
  • emissions reduction

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