What components does a transformer oil purifier consist of?

Transformer oil purifier is a device specially used for purifying, dehydrating, degassing and regenerating transformer oil. Its core components can be divided into filtering system, vacuum system, heating system, control system, etc., according to their functions. The following is a detailed explanation of the main components and their functions:

1. Filtration system

- Coarse filter

- Function: intercept larger particles in the oil (≥50 microns) to protect subsequent precision components.

- Type: metal mesh filter element, self-cleaning scraper filter.

- Fine filter

- Function: remove fine particles (1-10 microns) to ensure the cleanliness of oil products.

- Type: paper filter element, glass fiber filter element or polymer membrane filter element.

- Coalescing filter (optional)

- Function: gather tiny water droplets into large droplets for easy separation.

2. Vacuum system (core dehydration and degassing components)

- Vacuum pump

- Function: create a high vacuum environment (usually ≤0.1 kPa) to reduce the boiling point of water.

- Type: rotary vane vacuum pump, Roots vacuum pump (for large flow).

- Vacuum separation tank (vacuum chamber)

- Function: The oil is atomized or forms a thin film in the tank to accelerate the evaporation of water and gas.

- Design: It is often equipped with a spray device or a packing layer to increase the surface area of the oil.

- Condenser

- Function: Condensing the evaporated water vapor in the vacuum tank to prevent water vapor from entering the vacuum pump.

- Type: Water-cooled or air-cooled condenser.

- Exhaust valve

- Function: Exhaust the separated gas to maintain the vacuum degree of the system.

3. Heating system

- Electric heater/thermal oil heater

- Function: Raise the oil temperature to 50-65℃ (avoid exceeding 70℃ to prevent oxidation).

- Protection: Equipped with a temperature sensor and an overheating protection device.

- Temperature control system

- Function: Accurately control the heating temperature, usually linked with PLC.

4. Oil circulation system

- Oil inlet pump

- Function: Extract the oil to be treated from the transformer or oil tank.

- Type: gear pump, screw pump (suitable for high viscosity oil).

- Oil outlet pump

- Function: Transport the purified oil back to the transformer or tank.

- Pipeline and valve

- Material: stainless steel or oil-resistant rubber to avoid contamination.

- Key valve: solenoid valve (automatic flow control), ball valve (manual adjustment).

5. Control system

- PLC/microcomputer controller

- Function: Automatically control parameters such as temperature, vacuum, flow, etc.

- Monitoring instrument

- Vacuum gauge: Display system vacuum.

- Pressure gauge: Monitor filter element blockage (pressure difference alarm).

- Moisture sensor (optional): Online detection of moisture content in oil.

- Protection device

- Overload protection: Automatic shutdown when the motor is overcurrent.

- Liquid level switch: prevents the oil level in the vacuum tank from being too high.

6. Auxiliary components

- Oil level gauge: monitor the oil level in the vacuum tank.

- Defoamer: prevents the oil from bubbling and overflowing in the vacuum tank.

- Mobile chassis: a base with wheels for easy equipment transportation (mobile oil purifier).

Typical workflow

1. Oil inlet: The oil to be treated enters the heater after coarse filtration.

2. Heating: the oil temperature rises to the set value (such as 60℃).

3. Vacuum separation: The hot oil is atomized in the vacuum tank, and the water and gas evaporate and are extracted.

4. Fine filtration: the dehydrated oil passes through the fine filter to remove particles.

5. Oil return: The purified oil is sent back to the transformer by the oil outlet pump.

Selection considerations

- Flow rate: ｓｅｌｅｃｔ according to the oil volume of the transformer (such as 5000 L/h, 10000 L/h).

- Vacuum degree: The higher the vacuum degree, the better the dehydration effect (a two-stage vacuum pump can reach below 0.05 kPa).

- Compatibility: The filter material needs to be resistant to high temperature and oil corrosion (for example, heavy oil requires a special filter element).

Common brands such as Pall, CJC, Hifi Filter and other oil purifiers are based on the above structural design. Users can choose fixed or mobile equipment according to their needs.