Evaluation of tubular ceramic heat-exchanger materials in basic coal ash from coal-oil-mixture combustion. [Sialon]

Technical Report · Fri Oct 01 04:00:00 EDT 1982

DOI:https://doi.org/10.2172/6726692· OSTI ID:6726692

Ferber, M. K.; Tennery, V. J.

Tubes of ten different structural ceramic materials were exposed to the hot combustion gases from a coal-oil-mixture (COM) fuel in the Ceramic Recuperator Analysis Facility (CRAF) at an outer tube wall temperature of about 1240/sup 0/C for about 240 h. Air flow through each tube simulated the conditions in a tubular heat exchanger element. As-received and exposed materials and solidified coal slag were examined. Several important properties of the ceramics, including room-temperature helium permeability, room-temperature C-ring fracture strength, and thermal expansion from room temperature to 1100/sup 0/C were measured for both as-received and exposed specimens. The ten structural ceramics included six types of silicon carbide, a high-purity alumina, and three types of newly available sialons. Highly fluid basic coal slag deposited on the outer surfaces of the structural ceramic tubes during the coal combustion and all of the tubes lost significant fractions of their wall thickness. Exposure to the hot coal slag increased permeability of all the surviving tubes by about one order of magnitude. The room-temperature C-ring fracture strength for the five types of SiC and one type of Al/sub 2/O/sub 3/ ceramic decreased by about 3 to 60%. Siliconized types of SiC had strength reductions of 38 to 61%. Sintered ..cap alpha..-SiC showed the smallest strength reduction of 3%. The high purity Al/sub 2/O/sub 3/ had a strength loss of about 28%. The thermal expansion of these materials did not change significantly. 46 figures, 12 tables.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6726692
• Report Number(s): ORNL/TM-8385; ON: DE83001700
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320304* -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Waste Heat Recovery & Utilization
36 MATERIALS SCIENCE
360205 -- Ceramics
Cermets
& Refractories-- Corrosion & Erosion
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ASHES
CARBIDES
CARBON COMPOUNDS
CERAMICS
CHALCOGENIDES
CHEMICAL REACTIONS
COMBUSTION PRODUCTS
CORROSION
DATA
DISPERSIONS
EXPANSION
EXPERIMENTAL DATA
FRACTURE PROPERTIES
FUEL OILS
FUEL SLURRIES
FUELS
HEAT EXCHANGERS
INFORMATION
LIQUID FUELS
MATERIALS TESTING
MECHANICAL PROPERTIES
MIXTURES
NITRIDES
NITROGEN COMPOUNDS
NUMERICAL DATA
OILS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PERMEABILITY
PETROLEUM PRODUCTS
PNICTIDES
RESIDUES
SILICON CARBIDES
SILICON COMPOUNDS
SILICON NITRIDES
SLAGS
SLURRIES
SUSPENSIONS
TESTING
THERMAL EXPANSION
TUBES
WASTE HEAT UTILIZATION
WASTE PRODUCT UTILIZATION