| 摘要 |
<p>1,172,746. Determination of thermal conductivity. COMMISSARIAT A L'ENERGIE ATOMIQUE. Nov.28, 1967 [Nov.30, 1966], No. 54095/67. Heading G1D. Apparatus for measuring the thermal conductivity of a material comprises an envelope for containing a heating plate 1 sandwiched between two panel shaped samples 2, 3 of the material, the outer surfaces of the samples contacting walls 8, 9 of the envelope these walls being maintained at a constant temperature during a test, which temperature is in the region of but slightly below the temperature of the plate 1, the envelope being completed by a ring 10 inside which the plates 8, 9 can shift, the ring 10 also being maintained at a constant temperature, and a clearance being provided between the ring 10 and the lateral walls of the samples 2, 3. The temperature of the walls 8, 9 may be controlled by thermocouples connected to electric heaters in the walls, and the ring 10 may be such as to have a temperature gradient therealong ranging from the greatest value adjacent the plate 1 to the least value adjacent the walls 8, 9. In this way lateral heat losses from the samples 2, 3 are eliminated. The envelope is mounted inside a pressure tight container 13 and is embedded in granular material 16 in the form of spherical particles of alumina, zirconia quartz and a pressure may be applied to the material 16 and thus to the envelope to keep the components thereof in heat conducting relation by pressurizing bladders 17 inside the container 13. The gaseous atmosphere inside the container 13 may be monitored as to pressure, humidity, and composition, and the atmosphere in the container 13 may be circulated if desired. Measurements on the samples 2, 3 may be made at different attitudes by rotating the container 13 in bearings 21. Thermal insulation 14 is provided on the outside of the container 13 and the container is maintained at a constant temperature by a water heated tubular coil 15. By means of the above apparatus it is possible to measure the thermal conductivity of samples at different temperatures up to say 500‹C., and to study the effects of changes in pressure and/or humidity on the samples.</p> |
