Liquid Dielectrics Electrical and Physical Properties of Systems Containing Sparingly Soluble Oxidation Products in Liquid Paraffin

Abstract

To determine the significance of fluorescence and similar phenomena upon the optical measurements, solutions of different concentrations of Shell sample 100 in Nujol were made, and their optical densities (log 1/T) were measured on the Hardy spectrophotometer. The results showed that the oils obeyed Beer's law.Further work in which the transmission curves are being expressed by an equation is being carried on to provide constants that are a function of the color of the oils. In this manner it is hoped that a more definite correlation between the color and other properties of the oils may be obtained.

Liquid Dielectrics

“…The solution containing 2.7 per cent thianthrene crystallized upon cooling to 20 °C., but the resulting power factor values did not materially change as the system became heterogeneous. The fact that the systems containing thiophenol remained homogeneous and had low power factors at the higher concentrations and lower temperatures used is in contrast with the phenolcontaining systems previously studied (11), which upon cooling formed emulsions that had high power factors.…”

“…Inasmuch as all the systems with higher power factors than solutions containing equimolecular proportions of acid or base became heterogeneous upon cooling (whereupon their power factors increased), an alternative explanation seems possible. Previous work with soaps (8) and with oxidation products (11) showed that systems appearing to be homogeneous but becoming visually heterogeneous at lower temperatures often exhibit dielectric behaviors resembling those of heterogeneous rather than of homogeneous systems. Tri-n-butylamine From consideration of the data obtained it is believed that, although the presence of sufficiently high proportions of soluble salts resulting from reaction between nitrogen bases and carboxylic acids can cause high power factors in insulating oils, the presence of such compounds in proportions equivalent to the low nitrogen content of insulating oils does not appreciably affect the power factors of the solutions.…”

“…To minimize the number of variables, the authors prepared numerous systems consisting of liquid paraffin and one or more highly purified compounds selected to represent types of products that might be found in or formed in insulating oils during deterioration, and investigated the power factors and related properties of these systems. The systems investigated were prepared to simulate deteriorated oils containing oilsoluble oxidation products (IS, IS), sparingly soluble oxidation products (11), copper and lead soaps such as are formed by oxidation of oils in contact with these metals (8), and products resulting from corona discharge on insulating oils (16). For concentrations of contaminants that could reasonably be expected to be formed in service, significantly high power factors have been found only when one component of the contaminant is by itself incompletely soluble in the oil.…”