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Title: Evaluation of tubular ceramic heat exchanger materials in acidic coal ash from coal-oil-mixture combustion. [Sialon; alumina; CVD, sintered, and siliconized SiC]

Abstract

Tubes of five ceramic materials were exposed to the hot combustion gases from a coal-oil-mixture (COM) fuel in the Ceramic Recuperator Analysis Facility (CRAF) at about 1200/sup 0/C for about 500 h. Siliconized SiC, sintered ..cap alpha..-SiC, and chemically vapor deposited (CVD) SiC survived the long-term exposure with no major visible degradation. The alumina and sialon tubes were cracked extensively. Acidic coal slag deposited extensively on the upstream surface of all tubes. During cooldown, the slag did not strongly bond to any of the silicon carbide tubes, but a strong bond was developed with the alumina and sialon tubes. The silicon carbides corroded by a micropitting oxidation at the carbide-slag interface. The SiC and Si phases of siliconized SiC corroded at essentially the same rate. Exposure to hot coal slag increased the room-temperature helium permeability of all the SiC-based tubes. For KT and CVD SiC, both upstream and downstream sides exhibited expansion increases up to about 17% at 1000/sup 0/C. Sintered ..cap alpha..-SiC had much smaller increases. Al/sub 2/O/sub 3/ had an expansion increase of about 14% on the upstream side at 1000/sup 0/C but the downstream side was unchanged. 65 figures, 22 tables.

Authors:
;
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
OSTI Identifier:
5280230
Report Number(s):
ORNL/TM-7958
ON: DE82007122
DOE Contract Number:  
W-7405-ENG-26
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
20 FOSSIL-FUELED POWER PLANTS; 36 MATERIALS SCIENCE; ALUMINIUM OXIDES; PERFORMANCE TESTING; FOSSIL-FUEL POWER PLANTS; HEAT EXCHANGERS; MATERIALS TESTING; SILICON CARBIDES; SILICON NITRIDES; ASHES; CHEMICAL VAPOR DEPOSITION; COAL; COMBUSTION PRODUCTS; MICROSTRUCTURE; PERMEABILITY; PETROLEUM; SLAGS; TENSILE PROPERTIES; THERMAL EXPANSION; TUBES; VERY HIGH TEMPERATURE; ALUMINIUM COMPOUNDS; CARBIDES; CARBON COMPOUNDS; CARBONACEOUS MATERIALS; CHALCOGENIDES; CHEMICAL COATING; CRYSTAL STRUCTURE; DEPOSITION; ENERGY SOURCES; EXPANSION; FOSSIL FUELS; FUELS; MATERIALS; MECHANICAL PROPERTIES; NITRIDES; NITROGEN COMPOUNDS; OXIDES; OXYGEN COMPOUNDS; PNICTIDES; POWER PLANTS; RESIDUES; SILICON COMPOUNDS; SURFACE COATING; TESTING; THERMAL POWER PLANTS; 200101* - Fossil-Fueled Power Plants- Cooling & Heat Transfer Equipment & Systems; 360105 - Metals & Alloys- Corrosion & Erosion

Citation Formats

Ferber, M. K., and Tennery, V. J. Evaluation of tubular ceramic heat exchanger materials in acidic coal ash from coal-oil-mixture combustion. [Sialon; alumina; CVD, sintered, and siliconized SiC]. United States: N. p., 1981. Web. doi:10.2172/5280230.
Ferber, M. K., & Tennery, V. J. Evaluation of tubular ceramic heat exchanger materials in acidic coal ash from coal-oil-mixture combustion. [Sialon; alumina; CVD, sintered, and siliconized SiC]. United States. https://doi.org/10.2172/5280230
Ferber, M. K., and Tennery, V. J. 1981. "Evaluation of tubular ceramic heat exchanger materials in acidic coal ash from coal-oil-mixture combustion. [Sialon; alumina; CVD, sintered, and siliconized SiC]". United States. https://doi.org/10.2172/5280230. https://www.osti.gov/servlets/purl/5280230.
@article{osti_5280230,
title = {Evaluation of tubular ceramic heat exchanger materials in acidic coal ash from coal-oil-mixture combustion. [Sialon; alumina; CVD, sintered, and siliconized SiC]},
author = {Ferber, M. K. and Tennery, V. J.},
abstractNote = {Tubes of five ceramic materials were exposed to the hot combustion gases from a coal-oil-mixture (COM) fuel in the Ceramic Recuperator Analysis Facility (CRAF) at about 1200/sup 0/C for about 500 h. Siliconized SiC, sintered ..cap alpha..-SiC, and chemically vapor deposited (CVD) SiC survived the long-term exposure with no major visible degradation. The alumina and sialon tubes were cracked extensively. Acidic coal slag deposited extensively on the upstream surface of all tubes. During cooldown, the slag did not strongly bond to any of the silicon carbide tubes, but a strong bond was developed with the alumina and sialon tubes. The silicon carbides corroded by a micropitting oxidation at the carbide-slag interface. The SiC and Si phases of siliconized SiC corroded at essentially the same rate. Exposure to hot coal slag increased the room-temperature helium permeability of all the SiC-based tubes. For KT and CVD SiC, both upstream and downstream sides exhibited expansion increases up to about 17% at 1000/sup 0/C. Sintered ..cap alpha..-SiC had much smaller increases. Al/sub 2/O/sub 3/ had an expansion increase of about 14% on the upstream side at 1000/sup 0/C but the downstream side was unchanged. 65 figures, 22 tables.},
doi = {10.2172/5280230},
url = {https://www.osti.gov/biblio/5280230}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Dec 01 00:00:00 EST 1981},
month = {Tue Dec 01 00:00:00 EST 1981}
}