High temperature corrosion of advanced ceramic materials for hot gas filters and heat exchangers
- Pennsylvania State Univ., University Park, PA (United States); and others
A vertical flow-through furnace has been built to study the effect of corrosion on the morphology and mechanical properties of ceramic hot gas filters. Sections of 3M Type 203 and DuPont Lanxide SiC-SiC filter tubes were sealed at one end and suspended in the furnace while being subjected to a simulated coal combustion environment at 870{degrees}C. X-ray diffraction and electron microscopy is used to identify phase and morphology changes due to corrosion while burst testing determines the loss of mechanical strength after exposure to the combustion gases. Additionally, a thermodynamic database of gaseous silicon compounds is currently being established so that calculations can be made to predict important products of the reaction of the environment with the ceramics. These thermodynamic calculations provide useful information concerning the regimes where the ceramic may be degraded by material vaporization. To verify the durability and predict lifetime performance of ceramic heat exchangers in coal combustion environments, long-term exposure testing of stressed (internally pressurized) tubes must be performed in actual coal combustion environments. The authors have designed a system that will internally pressurize 2 inch OD by 48 inch long ceramic heat exchanger tubes to a maximum pressure of 200 psi while exposing the outer surface of the tubes to coal combustion gas at the Combustion and Environmental Research Facility (CERF) at the Pittsburgh Energy and Technology Center. Water-cooled, internal o-ring pressure seals were designed to accommodate the existing 6 inch by 6 inch access panels of the CERF. Tubes will be exposed for up to a maximum of 500 hours at temperatures of 2500 and 2600{degrees}F with an internal pressure of 200 psi. If the tubes survive, their retained strength will be measured using the high temperature tube burst test facility at Penn State University. Fractographic analysis will be performed to identify the failure source(s) for the tubes.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- OSTI ID:
- 458947
- Report Number(s):
- ORNL/FMP-96/1; CONF-9605167-; ON: DE97050349; TRN: 97:001933-0014
- Resource Relation:
- Conference: 10. annual conference on fossil energy materials, Knoxville, TN (United States), 14-16 May 1996; Other Information: PBD: Aug 1996; Related Information: Is Part Of Proceedings of the tenth annual conference on fossil energy materials; Cole, N.C.; Judkins, R.R. [comps.]; PB: 551 p.
- Country of Publication:
- United States
- Language:
- English
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High temperature corrosion of advanced ceramic materials for hot-gas filters and heat exchangers