Application of Square-wave Pulse Heat Method to Thermal Properties Measurement of CaO–SiO2–Al2O3 System Fluxes

Abstract

The square-wave pulse heat method was improved to measure thermal properties of vitreous samples by considering radiation heat transfer between the front and back faces of the samples, and the measurement accuracy of the method was examined.Thermal properties of CaO-SiO 2 -Al 2 O 3 samples were measured by the method. Thermal diffusivities of the crystalline 40CaO-40SiO 2 -20Al 2 O 3 (mol%) sample are about 1.5-2.5 times larger than those of the vitreous sample. Specific heat of the crystalline and vitreous samples shows almost the same temperature dependency, except the highest measurement temperature due to crystallization of glass.Finally, we investigated the reason that the thermal conductivity values measured by the improved square-wave pulse heat method differ from those by the line source method. As a result, crystallization of glass during the measurements would cause the difference of the temperature dependencies of the values measured by the two methods.KEY WORDS: square-wave pulse heat method; thermal diffusivity; specific heat; thermal conductivity; slags.

Thermophysical characterization of a by-product from the steel industry to be used as a sustainable and low-cost thermal energy storage material

“…As pointed out by Nishioka et al in Ref. [39], the thermal diffusivity of crystalline slag samples decrease with temperature whereas the associated to glassy slag shows a nearly constant value. This is in good agreement with our measurements corresponding to low and high crystallinity slags, Slag 1 and Slag 2 respectively, shown in Fig.…”

“…The measured C p values show similar temperature dependencies with the ones presented by Nishioka et al in Refs. [39], performed in materials of the same type. As can be seen in Fig.…”

Study of Solidification and Heat Transfer Behavior of Mold Flux Through Mold Flux Heat Transfer Simulator Technique: Part II. Effect of Mold Oscillation on Heat Transfer Behaviors

“…The known parameters used in the calculation and the calculated results are listed in Table III. The K cond is then calculated as 1.43 to 1.76 W m À1 K À1 , which is in agreement with those reported by Nishioka et al [17] who measured the thermal conductivities using square-wave pulse heat method and Ozawa et al [16] who used the hot wire method.…”

“…Ozawa et al [16] measured the lattice conductivities, refractive indices, and absorption/extinction coefficients of glassy and partially crystallized mold fluxes using the hot wire method. Nishioka et al [17] studied thermal diffusivity, heat capacity, and thermal conductivity of CaOSiO 2 and CaO-SiO 2 -Al 2 O 3 system slags through the square-wave pulse heat method. Susa et al [7] and Diao et al [18] studied the effect of crystallization of mold flux on the heat transfer rate by measuring the radiative thermal properties of mold slag, such as the absorption and extinction coefficient using a spectrophotometer.…”

Heat Recovery from High Temperature Slags: A Review of Chemical Methods

“…Nishioka et al [21] and Li et al [22] have measured the thermal conductivity of solid slags using square-wave pulse heat method and hot strip method separately over 296-1196 K and they found that the thermal conductivity slightly increased from 1 to 3 W/(m· K) with increasing temperature. The hot wire method has been proved a useful method to measure the thermal conductivity of liquid slags and Kang et al [23] and Nagata et al [24] have reported that thermal conductivity in slag melts ranges from 0.1 to 0.5 W/(m· K).…”