Detailed explanation of transformer oil filter machine

Detailed introduction of transformer oil filter equipment

The transformer oil filter (also known as the transformer oil vacuum filter) is professional equipment specially used to purify transformer oil and restore its insulation performance. It can effectively remove moisture, gas, particulate matter and oxidation products in the oil to ensure safe and stable operation of the transformer.

Main functions of the transformer oil filter

1. Deep dehydration: remove free water and dissolved water (can be reduced to ≤5ppm).

2. Efficient degassing: remove dissolved gas (H₂, O₂, etc.) to prevent partial discharge.

3. Precision filtration: remove particulate impurities (filtration accuracy can reach ≤1μm).

4. Restore insulation strength: restore the breakdown voltage to ≥60kV/2.5mm (IEC 60156 standard).

5. Extend the life of oil products: reduce oxidation and reduce acid value (≤0.01mgKOH/g).

Core structure of the transformer oil filter

| Components | Functional description |

|--------------------|-----------------------------------------------------------------------------|

| Vacuum system | Including vacuum pump, condenser, vacuum tank, used for dehydration and degassing (vacuum degree can reach ≤0.1kPa). |

| Heating system | Electric heating or thermal oil heating, control oil temperature at 60-65℃ (avoid high temperature oxidation). |

| Filtration system | Multi-stage filter element (coarse filtration + fine filtration), filter particulate matter (NAS 1638 4-6 level). |

| Coagulation separation system | Demulsification, separation of tiny water droplets in oil (optional). |

| Control system | PLC or microcomputer control, real-time monitoring of temperature, vacuum degree, flow rate and other parameters. |

Workflow of the transformer oil filter

1. Oil inlet: The oil to be treated enters the heater through coarse filtration (100μm).

2. Heating: The oil temperature rises to 60-65℃ (promotes water evaporation).

3. Vacuum dehydration and degassing: The oil is atomized in the vacuum tank, and the water and gas are extracted.

4. Precision filtration: Residual particles are intercepted by 1-5μm filter elements.

5. Oil output: The purified oil returns to the transformer or oil storage tank.

A[Oil to be treated] --> B[Coarse filtration] --> C[Heating] --> D[Vacuum dehydration] --> E[Fine filtration] --> F[Purified oil]

Key performance parameters (taking typical equipment as an example)

| Parameter | Standard value | Test method |

|--------------------|-------------------------------|---------------------------|

| Processing capacity | 1000-12000L/h | ｓｅｌｅｃｔ according to transformer capacity |

| Vacuum degree | ≤0.1kPa (absolute pressure) | Vacuum gauge calibration |

| Working temperature | 60±5℃ | Temperature sensor |

| Breakdown voltage | ≥60kV (after treatment) | IEC 60156 |

| Moisture content | ≤5ppm (after treatment) | ASTM D1533 |

Equipment selection guide

1. ｓｅｌｅｃｔ by transformer capacity:

- Small transformer (<1000kVA): ｓｅｌｅｃｔ 1000-3000L/h processing capacity.

- Large transformer (>10MVA): ｓｅｌｅｃｔ 6000-12000L/h processing capacity.

2. ｓｅｌｅｃｔ according to the degree of pollution:

- Mild pollution (water content <100ppm): ordinary vacuum oil filter.

- Severe pollution (emulsification/high acid value): requires coalescence + adsorption function.

3. Special needs:

- High altitude areas: ｓｅｌｅｃｔ an enhanced vacuum pump (compensate for low air pressure).

- Explosion-proof environment: ｓｅｌｅｃｔ Ex dⅡBT4 explosion-proof model.

Operation precautions

1. Safety regulations:

- The vacuum pump must be started before heating to prevent local overheating.

- When shutting down, turn off the heating first, then break the vacuum, and finally turn off the power.

2. Maintenance points:

- ｒｅｐｌａｃｅ the vacuum pump oil every 200 hours of operation.

- ｒｅｐｌａｃｅ the filter element immediately when the pressure difference is greater than 0.3MPa.

3. Oil compatibility:

- Mineral oil and silicone oil require different types of equipment (silicone oil requires solvent-resistant seals).

The transformer oil filter is key equipment for power maintenance. Correct selection and operation can extend the life of the transformer by more than 10 years. The treated oil must comply with the GB/T 7595-2017 operating standard and be re-inspected regularly (at least once a year). For ultra-high voltage equipment above 500kV, it is recommended to choose an online oil filter system to achieve real-time purification.