Ya. A. Landa

The enthalpy and specific heat of yttrium oxide at 1300–2100°K

ConclusionsThe temperature dependence of the enthalpy and heat capacity of Y2O3 over the range 1300–2100°K was determined by a combination of experimental and analytical methods. The equation obtained can be interpolated in a first approximation for the temperature range 298–1300°K.

Thermophysical properties of tar-bonded refractories

ConclusionsAn investigation was carried out of the thermal diffusivity of as-molded, heat-treated, and coked dolomite, magnesite and dolomite-magnesite tar-bonded refractories by the even-rate heating of flat specimens to 200–1600°C in an inert medium.The relation was determined between the thermal diffusivity and the heat-treatment conditions and composition of the specimens; it was established that the disturbance of the monotonic temperature dependence of the thermal diffusivity arises primarily from Ca(OH)2 dehydration; it was shown that the thermal diffusivity is a function not only of the temperature but also of the rate of heating.The thermal capacity was determined by a known method for 1000–1900°C and calculated from the additivity of the thermal capacity of coked tar-dolomite refractories. The determined and calculated values differed by not more than 5–10%.The thermal conductivity of tar-bonded refractories was determined from the data relating to the thermal diffusivity and thermal capacity and compared with published findings. Up to 1000–1400°C the results obtained in this investigation lie within the spread of the published data.

Thermal diffusivity of resin-bonded refractories over a wide temperature range

Results are shown of thermal diffusivity measurements made on resin-bonded refractories of various compositions and structures.

Fibrous heat-insulation materials use of the hot wire method to determine thermal conductivity of fibrous heat-insulation materials

ConclusionsIt is desirable to determine the thermal conductivity of materials in the form of plates 30–40 mm thick or of a layer of wool of the same thickness by the hot wire method throughout their service temperature range, beginning at room temperature.

Determining the enthalpy and specific heat of magnesia spinels in the range 1400–2200°K

ConclusionsTemperature functions were obtained for ΔH(T) and Cp(T) which can be used for calculating the thermodynamic functions of the spinels MgAl2O4 and MgCr2O4 in the temperature regions of their service (up to 2200°K), to supplement the existing relationships (up to 1800°K).

Hot-wire method of determining the thermal conductivity of refractory materials

ConclusionsThe advantages of the hot-wire method of determining the thermal conductivity of refractory products lie in the fact that it makes it possible to determine the true thermal conductivity directly in relation to a given temperature of the specimen. This fact distinguishes this method favorably from the methods based on the use of tablets and cylinders in which the thermal conductivity is related to the mean temperatures of the hot and cold sides on the specimen.The hot-wire method gives satisfactory results even when λ is low, i.e., 0.05–0.18 W/ m·deg K [in the standard method (GOST 12170-76) the lower limit in the determination of the thermal conductivity of refractories is 0.18 W/m·deg K]. The method is convenient for determining the thermal conductivity of refractories in granular and powder form.Among the disadvantages of the method are the fact that it cannot be used to determine the thermal conductivity of anisotropic materials, the complexity of the measuring process and the high degree of skill demanded from the operator, and the long duration of the measuring process at a given temperature.The investigations on the experimental device developed at the All-Union Institute of Refractories demonstrated that the hot-wire method can be used for refractories with a low or moderate thermal conductivity [λ<2–2.5 W/m·deg K] over the temperature range 20–900°C with an error of about 10%. The method is a promising one for determining λ also at a high temperature (up to about 1400°C).

Thermophysical properties of dielectric cermets of the Al2O3-Mo, -W, -Nb system

The thermophysical properties of dielectric cermets of the Al2O3-Mo, -W, -Nb system in the temperature range 50–1900°C were investigated. A semiempirical relation is used to correlate the experimental data.

Thermal conductivity of magnesite refractories in the range 500–1800°C

ConclusionsAn experimental setup was developed for studying the thermal conductivity of refractories up to 2300°C on the hot face of the specimen.In the average temperature range of 500–1800°C a study was made of the thermal conductivity of magnesite refractories of different porosity. The experimental data obtained satisfactorily agree with well-known literature and calculated values for the thermal conductivity coefficients.

Use of the chromatographic method of analyzing the combustion products of oil

SummaryThe Chromatographic method of analyzing the products of combustion of liquid and other fuels deserves wide use for studying heat units in the refractories industry.In connection with the complexity and novelty of the question it is desirable to continue methodical work in the presence of heavy hydrocarbons.Of interest is the development of complete analysis on the Chromatograph of combustion products, including H2, CO, CH4, CO2, and O2, and also of natural gases and other combustible gases.