Thermal conductivity of packed beds of refractory particles: Experimental results

Journal Article · Fri Aug 01 04:00:00 EDT 1997 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1997.tb03094.x· OSTI ID:532942

Fedina, I; Litovsky, E; Shapiro, M; Shavit, A ^[1]

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1. Technion-Israel Inst. of Tech., Haifa (Israel). Faculty of Mechanical Engineering

Experimental data on thermal conductivity of packed beds composed from various refractory particles (corundum, silica, magnesia, baddeleyite, yttrium oxide, spinel) obtained in the temperature range 400--2,000 K in various gases are presented. It is found that thermal conductivity of a bed composed from crushed refractory particles may change after the first and subsequent heatings. This occurs as a result of smoothing of particle surfaces and decreasing of contact heat barrier resistances between the granules. The influence of smoothing is most significant for beds composed from particles with sizes below 2 mm. In polydisperse beds, containing micrometer-size particles, sintering processes were found to occur at temperatures above 1,600 K. This led to a sharp increase of the bed thermal conductivity. In regimes where sintering did not take place, decreasing of particle size resulted in a decrease of the effective thermal conductivity. This is attributed to the increased number of contacts between the particles and the scattering of thermal radiation.

• Sponsoring Organization: USDOE
• OSTI ID: 532942
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 8 Vol. 80; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
MAGNESIUM OXIDES
PACKED BEDS
PARTICLE SIZE
POWDERS
SILICON OXIDES
SINTERING
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
THERMAL CONDUCTIVITY
YTTRIUM OXIDES
ZIRCONIUM OXIDES