REMOVAL OF DIESEL OIL WATER BY HYDRODYNAMIC DISPERSION
Authors: Zhalkin Denis , Zhalkin Sergij , Vinichenko Valentin , Skripchenko Sergij 
Published: June 2022

Water, sulfur and lead compounds can enter the oil from the combustion chamber ofa running diesel engine. Significant amounts of diesel oil are missing due to water or vapor in thewater system and exhaust gases, which creates emulsion and sediment (sludge) at relatively lowtemperatures and disrupts the lubrication and cooling of friction surfaces and increases wear ofengine parts. Such oil must be drained from the crankcase and regenerated.The most promising method of regeneration of rejected oil, including in the locomotive depot,is hydrodynamic dispersion, which allows to remove water and modify the aging products instead ofa complex process of coagulation or evaporation.The article considers the reason for heating oil during its hydrodynamic dispersion, based onthe probable assumption that heating is due to viscous (internal) friction of oil in the hydrodispersantand hydroelements that ensure its operation.During operation, the oil used in diesel internal combustion engines is a complex mixture ofcarbohydrates and additive components, has certain physicochemical and operational properties.The oil system of the running engine provides greasing and cooling of friction surfaces and is exposed to complex influence of high temperature, oxygen of air, fuel and products of wear of details of theengine and foreign impurity (dust, fuel, water), ie difficult physical and chemical processes occur.aging of oil ".The article considers the reasons for the violation of the oil properties of diesel locomotivesdue to the modes of operation of diesel engines and the ingress of water orits vaporinto the crankcasedue to leaks in the cooling system and exhaust gases. When water enters the oil, an emulsion isformed, which leads to the deterioration of the oil layer between the parts in the friction pairs andincreased wear of the crankshaft bearings with babbit filling fillings and other parts.The presence of water in the oil contributes to its interaction with additives and theirprecipitation, creating an oily sticky mass, which can lead to partial or complete cessation of oilsupply to friction surfaces, reducing the cooling capacity of refrigerated sections of locomotives andheat exchangers. Diesel oil, which has defective performance, is subject to replacement or high-costregeneration, ie the restoration of the original properties in order to reuse it. Regeneration is oneway to save oil.The following sequence of methods must be followed in the complex of technologicalprocesses of regeneration: mechanical – to remove free water and solid contaminants from oil,thermophysical – to evaporate fuel and water residues, as well as physicochemical – coagulation,adsorption. One of the following schemes is used: sludge – treatment with surfactants – fueldistillation – treatment with adsorbent – filtration.The application of these methods requires complex, expensive equipment with high energyconsumption, and this in a locomotive depot (or regional center), as a rule, is not economicallyfeasible.Water and fuel are removed in two stages: evaporation (water and fuel) and adsorption (water).Evaporation of spent oils is performed by heating without pressure or using vacuum without pressureor using vacuum with heating the oil to a temperature of 70-80 °C. This method of restoring theproperties of the oil, although it leads to positive results, but causes significant energy consumption.The most promising method of waste waste treatment is hydrodynamic dispersion, which allowsaging products to be modified instead of a complex coagulation process. In addition, water and fuelare removed from the oil during dispersion as a result of heating.This method can be used in locomotive depots in the regeneration of motor (diesel) oils, whichhave defective parameters for certain indicators.The most expedient is the use of hydrodynamic dispersant (HD) in volumetric hydraulic drivesand internal combustion engines, which with relatively simple design and manufacturability does notcause destruction of oil hydrocarbon molecules, does not require preparation and adjustment beforeoperation, its efficiency in pressure fluctuations decreases. GD is energy efficient, does not causedifficulties when built-in, its durability is higher than ultrasonic and cavitating dispersants.But for the application of GD it is necessary to determine its parameters and regenerationtemperature.The article considers the reason for heating oil during its hydrodynamic dispersion, based onthe probable assumption that heating is due to viscous (internal) friction of oil in the hydrodispersantand hydroelements that ensure its operation.At the same time, we accept the assumption that the oil pressure before the GD and its flow ratein the hydroelements is constant. It was found that the temperature of the oil when dispersed isproportional to its dynamic viscosity, the square of the velocity of the oil and inversely proportionalto the heat transfer coefficient and the radius of the tube, which agrees well with the proposedhypothesis that the cause of oil heating in hydrodynamic dispersion is viscous friction (equation 17),and the oil is heated from 70 ° C to 100 ° C depending on the pressure. The results of experimental studies have shown that the optimal mode of treatment of wateredoil with GD is a pressure of 0.5 MPa at the number of cycles N = 50 and a temperature of 130-135 °C, which is much lower than the flash point of the oil.