Verbrennungstechnische Optimierung vom Kohlekessel K11

Translated title of the contribution: Combustion optimization of the coal boiler K11

Christian Schnedl

Research output: ThesisMaster's Thesis


The fluidized bed boiler of the company Sappi located in Gratkorn is mainly fired with hard coal and sewage sludge, providing energy for the pulp and paper production on site. In order to increase the efficiency of the boiler an extensive material stream analysis was initially conducted and results were visualized within a balance. As a result high content of unburnt carbon in the fly ash was found to be the most crucial parameter affecting efficiency. Due to its importance, specific operational tests were implemented to assess the influence of various changes on this parameter. Subsequently different measures were derived from acquired findings in order to ensure better combustion efficiency. Thereby also other technical issues such as NOx-emissions or the characteristics of fluidization were taken into account. Among others, cyclone efficiency, quantity of air distribution and flue gas recirculation as well as the operation of the ash cooler were eventually identified as possible areas of improvement.
Translated title of the contributionCombustion optimization of the coal boiler K11
Original languageGerman
  • Raupenstrauch, Harald, Supervisor (internal)
  • Pollhammer, Werner, Co-Supervisor (internal)
Award date21 Oct 2016
Publication statusPublished - 2016

Bibliographical note

embargoed until 27-01-2021


  • fluidized bed
  • coal boiler
  • combustion efficiency

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