Transformer Oil Filter: Restoration After Long-Term Disuse

The oil filter is a device used to filter and purify contaminated oil products. It can restore or improve the properties of the oil, such as cleanliness,

water content, gas content, acidity, viscosity, flash point, insulating strength, and color. Oil filters are widely used in various industries, including mining,

metallurgy, petroleum, railways, machinery, chemical engineering, textiles, cement, power plants, and instrumentation. They are primarily employed to purify

various industrial oils, such as lubricating oils, hydraulic oils, and insulating oils, thereby extending the service life of equipment.

When a transformer oil filter has been unused for a long period, a series of checks and preparations are necessary to ensure that the equipment can operate

safely and efficiently. Below are detailed steps and precautions for restoring the filter to use:

I. Inspection and Preparation

1.Visual Inspection of the Equipment:

Check the exterior of the filter, including the casing, pipes, and valves, for any signs of damage or corrosion.

Ensure that the equipment is stored in a dry and clean environment, free from moisture and dust.

2.Internal Cleaning:

Open the equipment and clean out any residual oil sludge and impurities to ensure the interior is clean.

Inspect the vacuum tank, oil pump, and heater to ensure they are free from dirt. Clean them if necessary.

3.Electrical System Check:

Verify the safety and reliability of the electrical control system, including the temperature controller, motor, and vacuum pump.

Check the power and ground wires to ensure they are securely connected and that the power supply voltage meets the equipment requirements.

4.Vacuum Pump Check:

Check the oil level and quality in the vacuum pump, and replace the dedicated vacuum pump oil if necessary.

Start the vacuum pump and check for normal operation, listening for any unusual noises.

5.Filter and Seals Check:

Inspect the filter elements for blockages or damage, and replace them if necessary.

Check the seals for signs of aging or damage, and replace them if needed.

6.Cooling System Check:

Inspect the cooler to ensure it is clean. If necessary, remove any accumulated water.

Ensure that the cooling system valves are closed to prevent coolant leakage.

II. Startup Procedure

1.Equipment Connection:

Connect the inlet and outlet oil pipes of the filter to the transformer oil tank, ensuring a secure connection with no leaks.

2.Vacuum Pump Startup:

Open the valve on the vacuum pump’s intake pipe and start the vacuum pump. Observe whether the vacuum level rises normally.

Adjust the vacuum level setting on the electrical contact vacuum gauge according to the altitude.

3.Oil Inlet Operation:

When the vacuum level reaches the set value (typically -0.08 MPa), open the inlet valve to start the oil flow.

Monitor the oil level gauge to ensure that the oil level in the vacuum tank reaches the middle position.

4.Oil Outlet Operation:

Open the outlet valve and start the oil pump to begin the oil output.

Note that the outlet valve must be opened before starting the oil pump to prevent damage to the filter.

5.Heater Startup:

Once the oil circulation is normal, start the automatic control heater and set the temperature between 45°C and 65°C.

Depending on the volume of oil being processed and the ambient temperature, decide whether to activate the manual heater.

6.Observation and Adjustment:

Monitor the pressure gauge to ensure that the oil discharge pressure is between 0 and 0.4 MPa.

Adjust the opening of the inlet valve to balance the oil input and output.

7.Sampling and Testing:

After the equipment has run normally and the oil has circulated several times, take a sample from the sampling port for testing to ensure the oil quality is satisfactory.

III. Shutdown Procedure

1.Heater Shutdown:

Turn the temperature controller knob to “0” to stop the heating.

2.Continue Oil Inlet:

Allow the oil to continue circulating for 3 to 5 minutes without heating.

3.Vacuum Pump Shutdown:

Turn off the vacuum pump power and open the exhaust valve to release the vacuum.

4.Drain Remaining Oil:

Press the oil pump button to drain the remaining oil from the vacuum tank, then shut off the oil pump.

5.Clean the Cooler:

Open the valve at the bottom of the cooler to drain any residual oil or water, then close the valve.

IV. Precautions

1.Vacuum Pump Oil Quality:

While the vacuum pump is running, pay attention to the oil level and quality in the vacuum pump, and replace it if necessary.

2.Cooler Water Accumulation:

If a significant amount of water accumulates in the cooler during operation, drain it promptly.

3.Pressure Gauge Monitoring:

Regularly monitor the pressure gauge. If the pressure exceeds 0.3 MPa, clean or replace the filter elements.

4.Filter Screen Cleaning:

Regularly remove and clean the filter screens of the primary filter and secondary filter to maintain cleanliness.

5.Equipment Noise:

While the equipment is running, constantly monitor the noise from the pump and motor. If any abnormalities are detected, address them immediately.

By following the above steps and precautions, you can ensure that a transformer oil filter can be safely and efficiently restored to use after a long period of disuse.