Electrical cleaning of oils is the removal of mechanical impurities from the oils by means of an electric field. This approach is not completely new, but in this case it has not found a mass application, which may be due to an inadequate evaluation of the processes occurring during the time of interaction of the electric field and oil.
At the heart of the electro clearing is the deposition of suspended particles of mechanical impurities under the action of the electrostatic field that arises between the electrode and the particles. Particles acquire a certain charge due to triboelectricity of the oil flow. In this case, a number of phenomena are observed in the space between the electrodes: a partial leakage of an electric discharge, the recharging of some particles, electric convection of a liquid, and so on.
When the oil moves to the particle, the forces of hydraulic resistance act. It will begin to settle on the electrode when the value of the Coulomb force exceeds the value of these forces.
The main advantages of electric oil cleaning
- more compact in comparison with settling tanks of the cleaning unit;
- absence of moving parts, which are an integral part of centrifuges;
- stability of throughput and hydraulic resistance;
- possibility of process automation.
At the same time, there are a number of other issues that affect the practical application of transformer oil processing. In particular, it can be noted that the charge control processes in the materials used to isolate the electrodes are not thoroughly studied, which leads to charge exchange of particles and their removal from the purifier.
As a result, the performance of the device is reduced. Also, experts note the complexity of the design of electric cleaners and a fairly high qualification, which must have the attendants of such equipment. The listed moments restrain wide introduction of electric oil cleaners from mechanical impurities.