Mineral based oil used in transformers has chemical properties and dielectric strength which enables its function as insulator and cooling agent. The ability of the transformer is defined in its physical limit of energy transfer. The energy limit of the transformer depends on the loading profile in a given temperature.

Energy limit of transformers in a cold country like Russia differs from those in warm climates like France or South East Asia. Operating transformers within its energy limits avoids high temperature stress and maximizes energy transfer potential.

Transformer oil feasibility: Naphthene versus Paraffin

Though naphthenic oil was considered as superior choice for transformer oil, paraffin based oils gained prominence owing to its zero sulphur content. Absence of sulphur is impossible in naphthenic oils.

Naphthene based oil for cold countries

Naphthenic based mineral oils are preferred in cold places since they have low pour point in low temperatures owing to low wax content. Which is enhanced by its thermal cooling capacity and availability. However, naphthene based oil which has a boiling point at 425 degree celsius, has high fire risk and is becoming scarce owing to its poor biodegradability.

Naphthene based oil and climate exception

Naphthene based transformer oils are used in India, despite its high pour point and the country’s warm climate owing to its availability here.

Paraffin based oil for warm countries

Paraffin based oil on the other hand contains wax which contributes to its viscosity. Its boiling point is 530 degree celsius and oxidation products are insoluble. The paraffin based oil, which is obtained from paraffinic crude oil through solvent separation methods, displays viscosity in high temperature. Despite low oxidation rate, sludge is formed which halts heat dissipation.

Transformer oil filtration: Hering magic

Hering employs its transformer oil purification or degasification plants backed by century plus competence to remove sludge in transformer oils. The plant reduces boiling point by minimizing pressure, while oil is heated to evaporate moisture content. Other contaminants are removed through the filter system.

Hering’s systems are known for their robust design, longevity, reliability, ease of operations and maintenance. Clubbed with German precision, the plants are custom made as per client requirements.

The oil purification plants are available in three versions namely EOK Basic, EOK Standard and EOK Professional based on the complexity of the use. EOK Basic is used for new transformers and equipment with oil in storage. EOK Standard is used for on-site transformer service and repair. EOK Professional has minimized cleaning time.

Hering clubs with qualified partners to service plants older than 30 years and provides free training for client companies. Hering insists rigorous quality management in its product base covering transformer oil purification systems, transformer oil regeneration systems, PCB removal system, vacuum transformer drying ovens, waste oil recycling plants, reactivation clay polishing system, adsorbent mineral polishing system, transformer insulation drying and degassing system and online transformer insulation drying systems.