Conclusions
The coefficients of thermal conductivity of insulating refractories measured by the method prescribed in GOST 12170-66, using the recommended thermometers with a scale division of 0.1°C and thermal insulation made from firebrick with an apparent density of 1.0 g/cm3, are appreciably higher than data obtained by the cylinder method. At average temperatures of 200–500°C (400–1000°C on the hot face) the discrepancy comes within the range 50–200%; when Tmean=600–700°C (1200–1300°C on the hot face) the discrepancies diminish to 0–30%.
The maximum apparatus error in determining the thermal conductivity according to GOST 12170-66 with the use of Beckmann thermometers and low thermal-conducting linings is 10–30% for λ − 0.2–1.0 kcal/(m·h·deg), which greatly exceeds that indicated in the standard, ±10%. The maximum proportion in the error comes from the measurement of the drop in water temperature as it passes through the calorimeter. Consequently, the use of the standard recommended thermometers with scale divisions of 0.1°C is unacceptable for measurements on materials with a low thermal conductivity, since it may lead to errors of about 100%.
Detailed comparison of the results of measuring this factor on standard equipment using the Beckmann thermometers, and on the improved instrument designed by the Ukrainian Institute (the cylinder method), showed that the mean square deviation of the experimental values for thermal conductivity for identical specimens with respect to the interpolation curves in the case of standard determinations is 2–3 times greater than the corresponding deviation for the cylinder method.
In most experiments the interpolation curves λ=f(T) for the standard method is different by ±15–25% from the curves obtained with the cylinder method. This displacement apparently is due to certain constant errors connected with the unaccounted-for sources of error in the standard methods.
The proposed method of determining the coefficient of thermal conductivity is of interest for scientific-research work. The use of the cylinder method is industry is associated with difficulties in preparing the specimens — Editors.
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Literature cited
E. D. Devyatkova et al., FTT,2, No. 4, 738 (1960).
L. Ya. Liberman and M. I. Peisikhiz, Manual of the Properties of Steels [in Russian], Book 32, Mashgiz (1958).
A. M. Banaev and V. Ya. Chekhovskoi, Teplofiz. Vysokh. Temp.,3, No. 1, 53 (1965).
B. N. Egorov and V. I. Kondratenkov, Teplofiz. Vysokh. Temp.,6, No. 5, 901 (1968).
F. R. Charvat and W. D. Kingery, J. Amer. Ceram. Soc.,40, No. 9, 118 (1957).
J. Francl and W. D. Kingery, J. Amer. Ceram. Soc.,37, 80 (1954).
I. I. Vishnevskii and V. N. Skripak, Izv. AN SSSR, Neorg. Mater.,2, No. 10, 1820 (1966).
I. I. Vishnevskii and V. N. Skripak, Teplofiz. Vysokh. Temp.,7, No. 3, 444 (1969).
A. F. Kokchkova and V. V. Goncharov, Ogneupory, No. 9, 401 (1948); No. 10, 445 (1949); No. 1, 39 (1955).
GOST 12170-66. Refractory Products. Method of Determining the Coefficients of Thermal Conductivity [in Russian], Standartgiz (1968), p. 360.
US Standards, ASTM C 182-47, C 201–47, C 202–47.
I. I. Vishnevskii and V. N. Skripak, Ogneupory, No. 5, 227 (1964).
I. I. Vishnevskii and V. N. Skripak, Ogneupory, No. 12, 13 (1966).
I. I. Vishnevskii and V. N. Shripak, Ogneupory, No. 9, 9 (1966).
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Translated from Ogneupory, No. 8, pp. 45–52, August, 1971.
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Vishnevskii, I.I., Skripak, V.N. Thermal conductivity of insulating refractories measured by the standard method and by the cylinder method. Refractories 12, 523–529 (1971). https://doi.org/10.1007/BF01283080
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DOI: https://doi.org/10.1007/BF01283080