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Effects of High‐Conductivity Gases on the Thermal Conductivity of Insulating Refractory Concrete
Author(s) -
WYGANT J. F.,
CROWLEY M. S.
Publication year - 1958
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1958.tb13537.x
Subject(s) - helium , thermal conductivity , hydrogen , materials science , thermodynamics , thermal , composite material , convection , analytical chemistry (journal) , chemistry , physics , organic chemistry , chromatography
A method is described by which thermal conductivities can be determined in highly conductive gases without errors due to convection and radiation. Using a concrete composed of crushed insulating firebrick and aluminous cement, thermal conductivities were measured in helium. The k value rose slightly in helium at 1 atm. pressure, and much more in 200 lb. per sq. in. gauge helium. This was thought to be due to fracture of cell walls and greater helium permeation at high pressure. It is shown that several equations predict fairly accurately the k values in helium, using constants derived from k values in air. Calculations were made for K values in pure hydrogen, showing more than a 100% rise above those in air at moderate temperatures, and for k values in atmospheres containing various percentages of hydrogen.