Transformer oil filtration machine working principle

Transformer Oil Filtration Machine: Working Principle

Transformer oil filtration machines are designed to remove impurities, moisture, and gases from transformer oil to restore its insulating properties and extend the life of the transformer. These machines play a crucial role in ensuring that transformer oil remains clean and free of contaminants, which helps prevent electrical breakdown, overheating, and other performance issues in transformers.

The working principle of a transformer oil filtration machine generally involves a multi-stage purification process. Here’s how it works:

Key Contaminants in Transformer Oil:

1. Water (Free and Dissolved): Water in the oil can severely affect the oil's insulating properties, cause oxidation, and reduce the overall efficiency of the transformer.
2. Solid Particulates: These are dirt, dust, metal particles, and sludge that can increase the likelihood of electrical breakdown and cause wear on the transformer’s internal components.
3. Gases (Acids, CO₂, etc.): The presence of gases can be a sign of oil degradation and can cause issues in the transformer’s operation.
4. Acids: These are formed due to the breakdown of oil and can cause corrosion and further degradation of the oil.

Step-by-Step Working Principle of Transformer Oil Filtration Machine:

1. Oil Circulation and Pre-Heating:

   • The transformer oil is pumped into the filtration system from the transformer tank.
   • The oil is pre-heated using heating elements to bring it to an optimal temperature for filtration (typically between 60°C to 70°C). Pre-heating helps to lower the viscosity of the oil, making it easier to remove water and contaminants.

2. Coalescing Filtration (Water and Particulate Removal):

   • The oil passes through coalescing filters, where the system separates water from the oil.
   • In this stage, coalescing filter media causes tiny water droplets dispersed in the oil (both free and emulsified) to combine into larger droplets (coalescing).
   • These larger droplets are separated from the oil due to gravity or centrifugal force, and are removed from the system.
   • The solid particulates in the oil are also trapped by the filter media, preventing them from circulating back into the oil.

3. Vacuum Dehydration (Dissolved Water Removal):

   • The oil is drawn into a vacuum chamber where vacuum dehydration takes place.
   • The pressure in the chamber is lowered to create a vacuum, which reduces the boiling point of water.
   • This allows any dissolved water in the oil to evaporate at a much lower temperature, typically between 40°C to 60°C.
   • The water vapor is then condensed and collected in a separate chamber, while the oil remains free of dissolved moisture.

4. Filtration and Degassing (Fine Particulate and Gas Removal):

   • The oil continues through fine filtration units, which filter out any remaining microparticles and fine debris.
   • In some systems, the oil may also pass through degassing chambers, where any dissolved gases (such as oxygen, carbon dioxide, and hydrogen) are removed from the oil. This is usually done under vacuum conditions.
   • This process is crucial for restoring the insulating properties of the oil and ensuring there are no gases that could contribute to electrical breakdown.

5. Final Polishing:

   • After the oil has undergone filtration, dehydration, and degassing, it may pass through a polishing filter to further ensure that no small particles or traces of contaminants remain in the oil.
   • This final stage helps to ensure that the oil is of high purity and is ready for use.

6. Discharge and Refill:

   • Once the oil has been purified, it is discharged back into the transformer tank.
   • The system may also include a monitoring system to check the oil's properties (e.g., water content, acidity, and cleanliness level) to ensure it meets the required standards before it is reintroduced to the transformer.

7. Waste Collection:

   • The water and contaminants (e.g., sludge, acids, and particulate matter) removed from the oil are collected in separate containers and must be properly disposed of according to local environmental regulations.

Components of a Transformer Oil Filtration Machine:

1. Pump: To circulate the oil through the filtration system.
2. Heating Unit: To pre-heat the oil for optimal filtration performance.
3. Coalescing Filters: To separate water from oil (both free and emulsified water).
4. Vacuum Chamber: For vacuum dehydration to remove dissolved water.
5. Degassing Unit: To remove dissolved gases.
6. Fine Filters: To remove solid particulates and other fine contaminants.
7. Polishing Filters: To remove any remaining fine particles.
8. Waste Collection Tank: To collect contaminants such as water and sludge.
9. Control Panel: For monitoring and controlling the filtration process, including temperature, vacuum level, and flow rate.

Advantages of Transformer Oil Filtration Machines:

• Restores Insulating Properties: By removing water, gases, and particulates, the filtration system restores the insulating properties of transformer oil.
• Prevents Transformer Failure: Regular oil filtration reduces the risk of electrical breakdowns and overheating in transformers, extending their lifespan.
• Environmental Benefits: These systems help to purify and reuse transformer oil, reducing the need for oil replacement and minimizing environmental impact.
• Cost-Effective: While the initial investment may be high, transformer oil filtration machines save money in the long term by extending transformer life and reducing maintenance costs.

Applications of Transformer Oil Filtration:

• Power Plants: To ensure the oil in transformers used for power generation remains clean and free from moisture.
• Substations: For maintaining the quality of transformer oil in substations, preventing failure and improving efficiency.
• Industrial Transformers: In manufacturing industries with large transformers that require regular oil filtration and purification.
• Renewable Energy Systems: In wind and solar power facilities, where large transformers are often used for voltage conversion.

Conclusion:

A transformer oil filtration machine works through a combination of heating, coalescing filtration, vacuum dehydration, and fine filtration to remove contaminants like water, gases, and particulates from transformer oil. This process helps maintain the oil’s insulating properties and improves transformer performance, reliability, and lifespan. By regularly filtering the oil, transformers can operate efficiently and avoid costly downtime and repairs.