Thermal conductivity of nonassociated liquids

Abstract

and the void fraction of the bed were plotted against the corresponding Reynolds number, as shown in Figure 4. Only the data of studies in which surface temperatures were measured directly were utilized and include jh values for packed, expanded, and distended beds. No experimental heat transfer factors are presently available for fluidized beds. Again considerable scatter is noted at low Reynolds numbers, due to backmixing effects. The deviations of the in values reported by De Acetis and Thodos (3) can be attributed to the significant conduction and radiation effects which were not accounted for in that study. !The best relationship, which is limited to the region N R s > 20 for which substantial experimental data are available, may be expressed analytically as follows:The thermal conductivity of liquids numerical values, the largest and the coefficients are sufficiently sensitive to composed of nonionized molecules smallest known values differing by less the magnitude of the thermal conduccovers a comparatively small range of than a factor of 10. Yet heat transfer tivity (which is very difficult to meas-*The very similar relation X = (6.96 k/o*18) ( AEV/M where u = liquid volume/molecule, AEv = enerp of vaporizahon, has been derived from a solid Ike model of the liquid state by Altenburg (1).

Estimation of Heat Capacity of Liquids

“…Since the calculation is somewhat laborious and the Lennard-Jones potential is often a poor approximation to the facts, a simple correlation with the appropriate reduced temperature has been tried. It appears that the linear relation Ctx/R « 3.40 -1.0 T* (3) represents the data satisfactorily, if the mercury data are given more weight than the argon data (see Figure 1). The great age of the Cv data of argon and their greater deviation from theory than for mercury suggest that a redetermination is in order.…”

Thermodynamics of Polymer Solubility in Polar and Nonpolar Systems

“…where An is the interchange energy density for the solventsolute pair. The use of Equation 5, together w'ith the Flory-Huggins expression for the athermal configurational entropy of mixing, gives X = Xs + ~An (6) The interchange energy density, A¡2, is given by A12 = (fu + c22 -2c \2) (7) where the c,/s characterize the intermolecular forces acting between molecules (or molecular segments) i and j. For the pure components, cu and c22 are the cohesive energy densities of components 1 and 2 : In Equation 8, AE* is the energy of vaporization of substance i to a gas at zero pressure; \t and t¡ are defined, respectively, as the nonpolar and the polar solubility parameters of substance i.…”

Internal Pressure Measurements and Evaluation of External Molecular Vibrational Modes in the Liquid State

“…A molecule is thus vibrating as a whole in a potential well in the same way as a molecule in the solid state, which obeys the law of Dulong and Petit. The importance of these external degrees of freedom in the liquid state has been emphasized by Bondi (1962) in considering thermal conductivity and by Bondi and Simkin (1960) in work on a corresponding states correlation for liquids of higher molecular weight. Prigogine also discussed the influence of the external degrees of freedom on the evaluation of the partition function in liquid theory (Prigogine, 1957).…”