Reference Correlations for the Viscosity of Molten LiF-NaF-KF, LiF-BeF2, and Li2CO3-Na2CO3-K2CO3

Abstract

In 1974, reference correlations for the viscosity of molten LiF-NaF-KF, LiF-BeF2, and Li2CO3-Na2CO3-K2CO3 were proposed by Janz and have been extensively used since then. However, in the last 45 years, many additional measurements have been published. This is why in this paper, new reference correlations for the viscosity of these salts are proposed. All available experimental data for the viscosity of these three molten salts have been critically examined with the intention of establishing improved or new reference viscosity correlations. All experimental data have been categorized into primary and secondary data according to the quality of measurement specified by a series of criteria. The reference correlation proposed for LiF-NaF-KF, with an uncertainty of 2.9% at the 95% confidence level, expands the temperature range of the previous correlation from (770–970) K to (732–1163) K and retains its uncertainty. The correlation proposed for LiF-BeF2, with an uncertainty of 4.9% at the 95% confidence level, expands the high temperature range of the previous correlation from (740–870) K to (793–1573) K, with a slight loss in its uncertainty. It is, however, a much better correlation as it is based upon measurements not available at the time of the previous one. Finally, the reference correlation for Li2CO3-Na2CO3-K2CO3, with an uncertainty of 3%, also expands the temperature range of the previous correlation from (920–1170) K to (738–1170) K and retains its uncertainty.

New Design of the Falling-Body Rheoviscometer for High and Extra-High Viscous Liquid Measurements. Viscosity of Vacuum Oils

“…However, most complex molecular liquids and liquid mixtures are not obeyed to the linear Arrhenius behavior of viscosity (eq ) (see, e.g. refs ,,,,− ). The significant deviations from the linear Arrhenius behavior of viscosity were observed for pure and binary mixtures by many authors; see, for example, refs. ,,,,, As Figure shows, the present viscosity data for vacuum oils are deviating from the linear Arrhenius relation at temperatures above 400 K, that is, this model is applicable only in the limited temperature range.…”

“…refs ,,,,− ). The significant deviations from the linear Arrhenius behavior of viscosity were observed for pure and binary mixtures by many authors; see, for example, refs. ,,,,, As Figure shows, the present viscosity data for vacuum oils are deviating from the linear Arrhenius relation at temperatures above 400 K, that is, this model is applicable only in the limited temperature range. The empirical extension of the original linear Arrhenius eq by including the second term in eq allows considerable extension of the temperature range, where the linear Arrhenius–Andrade relation is applicable.…”

Saline: An API for Thermophysical Properties

“…Thermophysical properties of molten salts have been studied by various authors, and the measured data have been published [4]- [10]. The data and the experimental measurements or theoretical estimation methods used to generate them were compiled in several publications [11]- [17]. Janz et al prepared several reports on the existing thermophysical property data over the years [18]- [23].…”

Dynamic Viscosity of the NaF-KF-NdF3 Molten System

“…The viscosity of the molten (LiF-NaF-KF) eut (or FLiNaK) has been obtained by many researchers, since it is considered a promising medium for use as a coolant in molten salt reactors [10,21,22]. The measurements were carried out, as a rule, by the oscillatory or rotational method.…”

“…It should be noted that measurement results often differ, regardless of the method used. Tasidou et al [22] critically reviewed all known experimental data on the viscosity of FLiNaK, guided by the following criteria: a wide range of values should be presented with an accuracy of at least 1%, and an estimate of the measurement error should be given. The data of Janz [23] were considered as the most reliable, which, in turn, were based on the results of Torklep and Oye [11].…”