A large amount of waste oil is generated around the world annually, and the problem of proper disposal is yet to be solved. Using waste oil for fuel is often used, but is not environmentally safe. Treatment of oil to make it usable again is a better option.
Transformer oil treatment
If samples collected from transformer oil indicate that the acid number of the oil is approaching 0.2 mg KOH/g, this should be taken as the first sign that oil should be changed or treated to restore it. It should be noted that even a full oil change may not always be able to solve the problem. Even if the oil is thoroughly drained from the transformer, sludge and other contaminants may still remain in the oil. When the transformer is filled with new oil, these contaminants mix with the new oil and rapidly degrade its condition. With this in mind, GlobeCore engineers have developed the CMM-R unit. The main feature of this system is its ability to treat oil inside the transformer, which can be both online or offline during the process. The unit is connected to the transformer, and the cycle of oil circulation begins: the product requiring treatment goes into the unit and returns into the transformer clean. This allows to remove the aging products which would stay in case of simple oil change. The properties of the transformer’s insulation system are completely restored. This result is achieved by the combined use of degasser, regeneration, reactivation of sorbent and additive injection.
Other oil treatment methods
When the acid number of the oil is 0.2-0.4 mg KOH/g, it can be treated with other, simpler, processes, e.g. with synthetic adsorbents, such as silica gel or alumina oxide. Natural sorbents, such as bleaching clay, can also be used.
If the acid number of the oil is within 0.4-0.6 mg KOH/g, restoration may require treatment with sulfuric acid with subsequent bleaching clay treatment. Before applying these methods, particulate matter, water and gas should be removed from the oil.
Therefore, complete restoration of transformer oil is impossible without using adsorbents. The CMM-R unit, mentioned above, uses Fuller’s earth, which can be reactivated as many as 300 times, which is the equivalent of several years of operation. The material is reactivated inside the unit, simultaneously with oil treatment, if necessary.
If you wish to learn more about transformer oil treatment technologies, please visit globecore.com.