Transformer oil purification method

Transformer oil purification is an important step to ensure the normal operation of the transformer and extend its service life. Transformer oil may be affected by pollutants such as moisture, gas, and solid particles during use, resulting in a decrease in its insulation and cooling performance. The following are common transformer oil purification methods:

1. Physical purification method

(1) Vacuum dehydration and degassing

- Principle: By heating the transformer oil and lowering the boiling point of water under a vacuum environment, moisture and gas are evaporated and separated from the oil.

- Equipment: Vacuum dehydration and degassing machine.

- Applicable situations: Suitable for removing moisture and dissolved gas in oil.

- Advantages: Efficient removal of moisture and gas without chemical effects on oil quality.

(2) Mechanical filtration

- Principle: Remove solid particles and impurities in the oil through filter media such as filter paper, filter element or filter screen.

- Equipment: Plate and frame oil filter, centrifugal oil filter.

- Applicable situations: Suitable for removing mechanical impurities (such as metal particles, fibers, etc.) in the oil.

- Advantages: Simple operation and low cost.

(3) Centrifugal separation

- Principle: Use centrifugal force to separate the denser water and solid particles in the oil.

- Equipment: Centrifugal oil filter.

- Applicable situations: Suitable for removing free water and larger particle impurities.

- Advantages: Fast processing speed, suitable for large-scale oil processing.

2. Chemical purification method

(1) Adsorbent treatment

- Principle: Use adsorbents (such as silica gel, activated alumina, molecular sieves, etc.) to adsorb water, acidic substances and impurities in the oil.

- Equipment: Adsorption tower or oil filter.

- Applicable situations: Suitable for removing trace water and acidic substances.

- Advantages: Can effectively improve the chemical properties of oil.

(2) Chemical regeneration

- Principle: Neutralize the acidic substances in the oil by adding chemical reagents (such as alkali solution), or remove pollutants by chemical reaction.

- Equipment: Chemical regeneration device.

- Applicable situations: Suitable for oil with severe aging and high acid value.

- Advantages: Can restore the chemical properties of oil.

3. Comprehensive purification methods

(1) Vacuum oil filter

- Principle: Combine heating, vacuum dehydration and mechanical filtration to remove moisture, gas and solid impurities at the same time.

- Equipment: Vacuum oil filter.

- Applicable situations: Applicable to comprehensive purification of transformer oil.

- Advantages: High efficiency, comprehensiveness, suitable for large-scale treatment.

(2) Electrostatic oil purification

- Principle: Use electrostatic field to charge and aggregate tiny particles in the oil, making it easier to filter and remove.

- Equipment: Electrostatic oil filter.

- Applicable situations: Applicable to remove tiny particles and colloidal substances.

- Advantages: Good effect on removing tiny particles.

Transformer oil purification steps

1. Sampling and testing:

- Take transformer oil samples and test its moisture, gas content, acid value, dielectric strength and other indicators.

2. ｓｅｌｅｃｔ purification method:

ｓｅｌｅｃｔ a suitable purification method based on the test results and pollution situation.

3. Purification treatment:

Use corresponding equipment to treat transformer oil until the oil quality meets the standard.

4. Re-test:

- After purification, re-sample and test to ensure the oil quality meets the requirements (such as moisture content less than 10 ppm and dielectric strength greater than 50 kV).

5. Re-injection transformer:

- Re-inject the purified oil into the transformer and ensure that the transformer is well sealed.

Precautions

- Safe operation: Wear protective equipment when handling transformer oil to avoid skin contact or inhalation of oil vapor.

- Equipment maintenance: Regularly inspect and maintain the purification equipment to ensure its normal operation.

- Environmental control: During the purification process, oil should be kept away from air for a long time to prevent secondary contamination.

- Oil quality standards: The purified oil should meet relevant standards (such as GB/T 7595-2017 "Quality Standards for Transformer Oil in Operation").

The above methods can effectively purify the transformer oil and restore its insulation and cooling properties, thereby ensuring the safe and stable operation of the transformer.