Release of alkali salts and coal volatiles affecting internal components in fluidized bed combustion systems
DOI:
https://doi.org/10.3989/revmetalm.2003.v39.iExtra.1090Keywords:
Alkali deposition, Oxidation-sulfidation mechanism, Combustion modeling, Devolatilization kinetics, Fluidized bedsAbstract
In spite of the potential advantages of atmospheric fluidized bed systems, experience has proved that, under certain environments and operating conditions, a given material employed for internal components could lead to catastrophic events. In this study, an attempt is made to establish material selection and operational criteria that optimize performance and availability based on theoretical considerations of the bed hydrodynamics, thermodynamics and combustion process. The theoretical results may indicate that, for high-volatile coals with particle diameters (dc) of 1-3 mm and sand particle size (ds) of 0.674 mm, a considerable proportion of alkali chlorides may be transferred into the freeboard region of fluidized bed combustors as vapor phase, at bed temperatures (Tb) < 840 °C, excess air (XSA) ≤ 20 %, static bed height (Hs) ≤ 0.2 m and fluidizing velocity (Uo) < 1 m/s. Under these operating conditions, a high alkali deposition may be expected to occur in heat exchange tubes located above the bed. Conversely, when the combustors operate at Tb > 890 °C and XSA > 30 %, a high oxidation rate of the in-bed tubes may be present. Nevertheless, for these higher Tb values and XSA < 10 %, corrosion attack of metallic components, via sulfidation, would occur since the excessive gas-phase combustion within the bed induced a local oxygen depletion.
Downloads
Download data is not yet available.
Downloads
Published
2003-12-17
How to Cite
Arias del Campo, E., Keer-Rendon, A., Manzanares-Papayanopoulos, L., & Bautista-Margulis, R. (2003). Release of alkali salts and coal volatiles affecting internal components in fluidized bed combustion systems. Revista De Metalurgia, 39(Extra), 15–22. https://doi.org/10.3989/revmetalm.2003.v39.iExtra.1090
Issue
Section
Articles
License
Copyright (c) 2003 Consejo Superior de Investigaciones Científicas (CSIC)
This work is licensed under a Creative Commons Attribution 4.0 International License.
© CSIC. Manuscripts published in both the printed and online versions of this Journal are the property of Consejo Superior de Investigaciones Científicas, and quoting this source is a requirement for any partial or full reproduction.All contents of this electronic edition, except where otherwise noted, are distributed under a “Creative Commons Attribution 4.0 International” (CC BY 4.0) License. You may read here the basic information and the legal text of the license. The indication of the CC BY 4.0 License must be expressly stated in this way when necessary.
Self-archiving in repositories, personal webpages or similar, of any version other than the published by the Editor, is not allowed.