The analysis of the watered engine oil sludge

BACKGROUND: Researches in the field of engine oils sludging take its origin from 1955. Scientists from different countries were searching for the reasons, defining consequences, building a chain of cause-effect links. Researchers have found that sludge represents a complex of compounds with low aggregative stability, such as: the additives inserted into a basis during production, partially oxidised fuel fractions subjected to thermal destruction, products of thermo-oxidative transformations of oil hydrocarbons. A number of factors stimulate transient processes of products with low aggregative stability. One of these factors is presence of water. Water may penetrate through ambient air, during engine service (washing), and as a result of condensation processes during operation at low temperature mode. Strengthening intermolecular interactions of compounds, water initiates sludging.

AIMS: Verification of the hypothesis about the binding effect of water on the composite package of additives, the content of which is determined by their indicator elements.

MATERIALS AND METHODS: The experiment was carried out under laboratory conditions. Production engine oils were watered intentionally in order to obtain sludge. Mixes of engine oils with water were made in different proportions. The formed sludge was separated from the mixes for the further research.

The search of the elements-indicators of additives in the analytical sample of a watered oil sludge was carried out with the method of raster electron microscopy. The Japanese-manufactured labware was represented by the Jeol JCM-5700 raster electronic microscope, the JED-2300 Analys Station software package. A raster microscope is the device intended for acquisition of object images, increased in several thousand times and with the huge spatial resolution, definition of chemical elements and their compounds.

RESULTS: The experiment conclusions are formulated on the basis of visual investigations and the raster electron microscopy studies.

CONCLUSIONS: The practical importance lies in integrity of the approach to the engine oils state change under the influence of water, regarding transition of the dissolved additives to a firm (amorphous) state. Possible consequences of watering are blocking of oil pickup screens and filtering elements, unfairly active corrosion and wear processes of surfaces of the related details.