Evaluation of materials for use in letdown valves in coal-liquefaction systems. Final report

Technical Report · Thu Apr 01 04:00:00 EST 1982

OSTI ID:5414284

Mueller, J L; Wright, I G

A number of advanced ceramics materials were evaluated in a test facility in which ash-containing coal derived slurry was used as the erodant in a jet impingement-type test designed to evaluate the wear characteristics of letdown valve trim component materials. The advanced ceramic materials evaluated were alumina, alumina-titanium carbide, boron carbide, silicon carbide, tungsten carbide, titanium diboride, hot pressed diamond, CVD codeposited tungsten-carbon and borided steel. Many of the materials were obtained in different forms and from different suppliers in the same form to determine the associated variability in erosion resistance. Each material was either commercially available or in such a state of development that it could be available commercially in the near future. Among the materials evaluated, chemically vapor deposited (CVD) silicon carbide was found to offer the greatest erosion resistance and a definite improvement over the cemented carbides in use in pilot plants. Both a compacted diamond product and a CVD form of silicon nitride showed promise. The latter materials would definitely require an improvement in the process of manufacture. Tests of seven different grades or types of alumina showed that all were unacceptable for letdown service. Both the alumina and the CVD silicon carbide displayed a broad range of variation in the erosion behavior, confirming that erosion resistance can differ greatly between grades and form of a given generic ceramic. CVD titanium diboride, which possessed outstanding wear resistance in pneumatically driven-particle erosion studies, was found in this work to be significantly less resistant than CVD silicon carbide to erosion by coal-derived slurry.

• Research Organization: Battelle Columbus Labs., OH (USA)
• OSTI ID: 5414284
• Report Number(s): EPRI-AP-2356; ON: DE82903571
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010405* -- Coal
Lignite
& Peat-- Hydrogenation & Liquefaction
36 MATERIALS SCIENCE
360200 -- Ceramics
Cermets
& Refractories
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BORIDES
BORON CARBIDES
BORON COMPOUNDS
CARBIDES
CARBON
CARBON COMPOUNDS
CERAMICS
CHALCOGENIDES
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
COAL LIQUEFACTION
COAL LIQUEFACTION PLANTS
CONTROL EQUIPMENT
DATA
DEPOSITION
DIAMONDS
DISPERSIONS
ELEMENTAL MINERALS
ELEMENTS
EQUIPMENT
EROSION
EXPERIMENTAL DATA
FAILURE MODE ANALYSIS
FLOW REGULATORS
INDUSTRIAL PLANTS
INFORMATION
LIQUEFACTION
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
METALLOGRAPHY
MINERALS
MIXTURES
NONMETALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE TESTING
SILICON CARBIDES
SILICON COMPOUNDS
SLURRIES
SURFACE COATING
SUSPENSIONS
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
TEST FACILITIES
TESTING
THERMOCHEMICAL PROCESSES
TITANIUM BORIDES
TITANIUM CARBIDES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN CARBIDES
TUNGSTEN COMPOUNDS
VALVES
WEAR RESISTANCE