High vacuum transformer oil purification systems are designed to remove contaminants like moisture, gases, and solid particles from transformer oil, restoring its insulating and cooling properties. Here’s how they work:
Oil Heating:
The oil is heated to lower its viscosity, making it easier to process and improving the efficiency of moisture and gas removal.
Vacuum Dehydration:
The heated oil is exposed to a high vacuum in a vacuum chamber. The vacuum lowers the boiling point of water, causing any dissolved moisture in the oil to evaporate and be drawn out of the oil. This process also removes dissolved gases, which can affect the dielectric strength of the oil.
Filtration:
After dehydration, the oil passes through fine filters that remove solid contaminants such as dirt, sludge, and metal particles. The filtration process ensures that the oil is free from impurities that can degrade the transformer’s performance.
Degassing:
The vacuum system also removes dissolved gases like oxygen and nitrogen, which can form bubbles and negatively impact the oil’s insulating properties. The oil is subjected to multiple stages of degassing, ensuring that it is thoroughly free of gases.
Cooling:
After purification, the oil is cooled back to a suitable operating temperature before being recirculated into the transformer.
Recirculation:
The purified oil is then pumped back into the transformer, restoring its insulating and cooling efficiency. Continuous monitoring may be used to ensure that the oil meets the required dielectric strength and purity levels.