Colorimetric methodology for monitoring the cellulose insulating paper degradation in electrical equipments filled with mineral oil

Abstract

During the operation of electrical equipments the compound 2-furfuraldehyde (2-FAL) and other related furanic substances are produced from the insulating paper degradation and can be detected in the mineral oil by high performance liquid chromatography (HPLC). Their concentration increase can be used to estimate the quality of the paper insulation inside the equipments. In this work colorimetric methodologies for quantification of these furanic degradation products in oil filled electrical equipment were evaluated. Two analytical methods were studied using aniline and modified Winkler's reactions. For this purpose used oil samples and 2-FAL standard oil solutions were analyzed and the results for both methods were compared with HPLC analysis. The obtained results for 2-FAL standard oil solutions were in accordance with both methodologies. The results obtained for used mineral oil showed that the analysis of furanic compounds by the colorimetric methods may induce to false positive results due to the interference of oil oxidation byproducts in the quantitative analysis.

Photoluminescence Induced in Mineral Oil by Ionizing Radiation

“…Additional drawbacks of current protocols include requirements of a relatively large amount of the oil (tens of milliliters), multistep sample preparations and rather complex experimental equipment [14]. Optical methods of oil characterization were suggested as an attractive alternative to other physical techniques [15][16][17][18]. Their obvious advantage is their non-destructiveness and the possibility of online control of the oil during operation.…”

Effects of drought stress and rehydration on physiological and biochemical of four oak species in China

“…Quercus fabri Hance, Quercus serrata Thunb, Quercus acutissima Carruth and Quercus variabilis Bl are the dominant species in deciduous broad-leaved forests and mixed coniferous forests in temperate and warm temperate regions of China and are also the forest building blocks in most parts of the country, with northern China as the centre of distribution (Wu et al 2012. Oak tree wood is dense and beautifully textured, resistant to wear and decay and is often used as a high-quality material for building and household purposes (Blanchet et al 2008). Oak tree bark can be used for extracting tannins, young leaves can be used to raise sericulture, and dead branches can also be used to cultivate valuable medicinal herbs such as edible mushrooms and ganoderma lucidum (Silva et al 2016).…”