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Title: ADVANCED HOT GAS FILTER DEVELOPMENT

Abstract

This report describes the fabrication and testing of continuous fiber ceramic composite (CFCC) based hot gas filters. The fabrication approach utilized a modified filament winding method that combined both continuous and chopped fibers into a novel microstructure. The work was divided into five primary tasks. In the first task, a preliminary set of compositions was fabricated in the form of open end tubes and characterized. The results of this task were used to identify the most promising compositions for sub-scale filter element fabrication and testing. In addition to laboratory measurements of permeability and strength, exposure testing in a coal combustion environment was performed to asses the thermo-chemical stability of the CFCC materials. Four candidate compositions were fabricated into sub-scale filter elements with integral flange and a closed end. Following the 250 hour exposure test in a circulating fluid bed combustor, the retained strength ranged from 70 t 145 percent of the as-fabricated strength. The post-test samples exhibited non-catastrophic failure behavior in contrast to the brittle failure exhibited by monolithic materials. Filter fabrication development continued in a filter improvement and cost reduction task that resulted in an improved fiber architecture, the production of a net shape flange, and an improved lowmore » cost bond. These modifications were incorporated into the process and used to fabricate 50 full-sized filter elements for testing in demonstration facilities in Karhula, Finland and at the Power Systems Development Facility (PSDF) in Wilsonville, AL. After 581 hours of testing in the Karhula facility, the elements retained approximately 87 percent of their as-fabricated strength. In addition, mechanical response testing at Virginia Tech provided a further demonstration of the high level of strain tolerance of the vacuum wound filter elements. Additional testing in the M. W. Kellogg unit at the PSDF has accumulated over 1800 hours of coal firing at temperatures of 760 °C including a severe thermal upset that resulted in the failure of several monolithic oxide elements. No failures of any kind have been reported for the MTI CFCC elements in either of these test campaigns. Additional testing is planned at the M. W. Kellogg unit and Foster Wheeler unit at the PSDF over the next year in order to qualify for consideration for the Lakeland PCFB. Process scale-up issues have been identified and manufacturing plans are being evaluated to meet the needs of future demand.« less

Authors:
Publication Date:
Research Org.:
Federal Energy Technology Center (FETC), Morgantown, WV, and Pittsburgh, PA
Sponsoring Org.:
USDOE
OSTI Identifier:
7132
Report Number(s):
DE-AC21-94MC31212-01
ON: DE00007132
DOE Contract Number:  
AC21-94MC31212
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; Hot Gas Cleanup; Filters; Ceramics; Composite Materials

Citation Formats

WAGNER, RICHARD A. ADVANCED HOT GAS FILTER DEVELOPMENT. United States: N. p., 1998. Web. doi:10.2172/7132.
WAGNER, RICHARD A. ADVANCED HOT GAS FILTER DEVELOPMENT. United States. https://doi.org/10.2172/7132
WAGNER, RICHARD A. 1998. "ADVANCED HOT GAS FILTER DEVELOPMENT". United States. https://doi.org/10.2172/7132. https://www.osti.gov/servlets/purl/7132.
@article{osti_7132,
title = {ADVANCED HOT GAS FILTER DEVELOPMENT},
author = {WAGNER, RICHARD A},
abstractNote = {This report describes the fabrication and testing of continuous fiber ceramic composite (CFCC) based hot gas filters. The fabrication approach utilized a modified filament winding method that combined both continuous and chopped fibers into a novel microstructure. The work was divided into five primary tasks. In the first task, a preliminary set of compositions was fabricated in the form of open end tubes and characterized. The results of this task were used to identify the most promising compositions for sub-scale filter element fabrication and testing. In addition to laboratory measurements of permeability and strength, exposure testing in a coal combustion environment was performed to asses the thermo-chemical stability of the CFCC materials. Four candidate compositions were fabricated into sub-scale filter elements with integral flange and a closed end. Following the 250 hour exposure test in a circulating fluid bed combustor, the retained strength ranged from 70 t 145 percent of the as-fabricated strength. The post-test samples exhibited non-catastrophic failure behavior in contrast to the brittle failure exhibited by monolithic materials. Filter fabrication development continued in a filter improvement and cost reduction task that resulted in an improved fiber architecture, the production of a net shape flange, and an improved low cost bond. These modifications were incorporated into the process and used to fabricate 50 full-sized filter elements for testing in demonstration facilities in Karhula, Finland and at the Power Systems Development Facility (PSDF) in Wilsonville, AL. After 581 hours of testing in the Karhula facility, the elements retained approximately 87 percent of their as-fabricated strength. In addition, mechanical response testing at Virginia Tech provided a further demonstration of the high level of strain tolerance of the vacuum wound filter elements. Additional testing in the M. W. Kellogg unit at the PSDF has accumulated over 1800 hours of coal firing at temperatures of 760 °C including a severe thermal upset that resulted in the failure of several monolithic oxide elements. No failures of any kind have been reported for the MTI CFCC elements in either of these test campaigns. Additional testing is planned at the M. W. Kellogg unit and Foster Wheeler unit at the PSDF over the next year in order to qualify for consideration for the Lakeland PCFB. Process scale-up issues have been identified and manufacturing plans are being evaluated to meet the needs of future demand.},
doi = {10.2172/7132},
url = {https://www.osti.gov/biblio/7132}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Sep 04 00:00:00 EDT 1998},
month = {Fri Sep 04 00:00:00 EDT 1998}
}