The Role of Vaccum Oil Purifier in Transformer Oil Purification

Transformer oil plays a critical role in the performance and longevity of electrical transformers, serving as both an insulating and cooling medium. However, over time, transformer oil becomes contaminated with impurities such as moisture, solid particles, and dissolved gases. These contaminants degrade the oil’s insulation properties, reduce its cooling efficiency, accelerate oxidation, and may lead to severe transformer failures. Regular purification of transformer oil is therefore essential to ensure the reliable operation of power systems.

Among the various transformer oil purification technologies, the vacuum oil purifier stands out due to its high efficiency, reliability, and cost-effectiveness. As a key category of transformer oil purifiers, vacuum oil filtration machines are specifically designed to remove contaminants rapidly and effectively using centrifugal force. This article provides an in-depth analysis of vacuum oil purifiers, including their working principles, advantages, applications, purification standards, and selection criteria.

Working Principle of Vaccum Oil Purifier

The working mechanism of a transformer oil centrifuging machine is based on centrifugal separation, which exploits the differences in density between oil, water, and solid contaminants. When contaminated transformer oil enters the centrifuge, the high-speed rotating drum generates a powerful centrifugal force. Due to the significant difference in density, heavier impurities such as water droplets and solid particles move outward to the drum wall, while the purified oil remains in the center and is discharged separately.

Compared with traditional filtration and vacuum dehydration methods, centrifugal separation offers several advantages:

• High Separation Efficiency – The centrifugal force is much greater than the gravitational force, enabling the rapid removal of fine particles and moisture.
• Continuous Processing Capability – Unlike batch-type purification systems, centrifuges can operate continuously, making them ideal for large-scale oil purification.
• Versatile Contaminant Removal – Centrifugal separation is effective in eliminating various impurities, including suspended solids, free water, and dissolved gases.
• Low Maintenance Costs – The robust design and simple structure of centrifuging machines lead to minimal maintenance requirements and reduced operational costs.

Working Principle of Vacuum Oil Purifier

The vacuum oil purification process operates on the principles of dehydration, degasification, and filtration. It involves several key stages:

1. Heating and Initial Filtration:

• The transformer oil is drawn into the purifier and passes through a pre-filter to remove large particles.
• The oil is then heated to an optimal temperature (typically 60–80°C) to reduce viscosity and enhance moisture and gas removal.

2. Vacuum Dehydration and Degasification:

• The heated oil enters a vacuum chamber, where it is exposed to a low-pressure environment (typically 0.05–0.09 MPa).
• Under vacuum conditions, moisture and dissolved gases (such as oxygen, nitrogen, and hydrogen) evaporate at a lower temperature.
• Specially designed diffuser plates or a spray nozzle system increase the surface area of the oil, allowing more efficient degasification and dehydration.

3. Fine Filtration:

• The partially purified oil then passes through multi-stage fine filters (1–5 microns) to remove any remaining particulate contaminants.
• Some systems may include an activated alumina or molecular sieve filter to absorb dissolved acids and polar contaminants.

4. Re-circulation and Final Purification:

• The purified oil is re-circulated through the system until it reaches the required breakdown voltage and moisture content specifications.
• Some advanced systems include an automatic moisture and gas detection unit to monitor the process.

Applications of Vacuum Oil Purifier

Application in Different Types of Transformer Oils

Vacuum oil purifiers are widely used for purifying different types of transformer oils, including:

• Mineral-Based Transformer Oil: This is the most commonly used type of transformer oil. Centrifuging enhances its performance by removing solid and liquid contaminants, thereby extending its service life.
• Synthetic Transformer Oil: Synthetic oils offer superior electrical and thermal properties but are more expensive. Proper purification with vacuum machines ensures their longevity and optimal performance.
• Natural Ester and Biodegradable Oils: With growing environmental concerns, natural ester oils are gaining popularity as an eco-friendly alternative. Vacuuming helps maintain their stability by eliminating impurities that may accelerate aging.

Application in Different Transformer Voltage Levels

• Low-Voltage Transformers (≤1kV): Although these transformers have lower oil purity requirements, regular oil purification extends their service life.
• Medium-Voltage Transformers (1kV-69kV): Medium-voltage transformers demand cleaner oil to ensure reliable operation, making vacuum a valuable purification method.
• High-Voltage Transformers (≥69kV): High-voltage transformers have stringent oil purity requirements, and vacuuming plays a critical role in maintaining their insulation properties.
• Ultra-High Voltage (UHV) Transformers (>800kV): UHV transformers require exceptional oil quality, necessitating the use of vacuum oil filter machines in combination with other purification technologies.

Standards of Transformer Oil in Vacuum Machine Purification

Transformer oil purification must meet industry standards to ensure electrical and mechanical reliability. Some key parameters include:

• Moisture Content: According to IEC 60422, the moisture content in service transformer oil should be below 20 mg/kg to prevent insulation degradation.
• Particle Contamination: Based on ISO 4406 or NAS 1638 standards, purified transformer oil must have a low particle count to minimize the risk of electrical failure.
• Dielectric Strength: The breakdown voltage of purified transformer oil should be high enough to maintain effective insulation.
• Acid Value: A lower acid number indicates that the oil has not undergone significant oxidation. Vacuuming helps maintain this parameter within acceptable limits.

How Vaccum Oil Purifier Ensures Compliance

• High-Speed Separation: The intense centrifugal force effectively removes contaminants that could compromise oil purity.
• Advanced Control Systems: Modern centrifuging machines feature precise automation for optimized purification.
• Multi-Stage Purification: Some machines incorporate multi-stage separation for enhanced efficiency.

How to Select a High-Quality Vaccum Oil Purifier

Selecting the right vacuum oil purifier is crucial to ensuring optimal purification performance, efficiency, and longevity. When evaluating different machines, consider the following key factors:

• Processing Capacity: Choose a vacuum oil filter machine that matches your transformer oil volume and purification needs. Large-scale operations require machines with higher throughput to handle continuous purification efficiently.
• Separation Efficiency: High-speed centrifuges with advanced centrifugal force mechanisms ensure superior contaminant removal, including fine particulates, free water, and dissolved gases.
• Operational Stability: The machine should be robust, durable, and resistant to frequent breakdowns, minimizing downtime and maintenance costs.
• Automation Level: Automated controls and intelligent monitoring systems enhance efficiency, reduce human intervention, and optimize the purification process.
• After-Sales Support: Reliable manufacturers provide excellent technical support, spare parts availability, and after-sales services to ensure long-term operation.

Why Choose Yuneng Oil Purifier?

For those seeking a high-performance vacuum oil filter machine, Yuneng Oil Purifier is a top-tier choice. Yuneng is a globally recognized manufacturer specializing in oil purification technology, offering state-of-the-art solutions designed for superior efficiency and reliability.

Here’s why Yuneng stands out:

• High Purification Efficiency – Yuneng’s vacuum oil purification machines utilize cutting-edge centrifugal separation technology to effectively remove moisture, particulate matter, and gas contaminants, ensuring optimal oil quality.
• Advanced Automation – Featuring intelligent control systems, Yuneng’s machines provide real-time monitoring, automatic sludge discharge, and self-adjusting purification cycles for maximum efficiency.
• Robust and Durable Design – Manufactured with high-quality materials, Yuneng’s equipment is built for long-term operation, with minimal maintenance requirements and excellent reliability.
• Customizable Solutions – Yuneng offers tailored vacuum oil purification machines to meet specific industrial requirements, whether for small-scale applications or large-scale power transformer maintenance.
• Comprehensive After-Sales Support – With a dedicated service team, Yuneng provides professional guidance, installation support, and ongoing maintenance assistance, ensuring customers receive the best value.

Where to Buy Yuneng Oil Purifiers?

• Official Website – Visit Yuneng’s official website to explore product specifications, request quotes, and get expert consultation.
• Authorized Distributors – Yuneng’s products are available through a global network of certified dealers and distributors.
• Industry Exhibitions & Trade Shows – Meet Yuneng representatives at electrical industry expos to see the latest oil purification technology in action.

By choosing Yuneng Oil Purifier, you ensure that your transformer oil purification process is efficient, cost-effective, and reliable—enhancing the lifespan and performance of your transformers.

In Summary

The vacuum oil purifier is a critical component of transformer oil purification systems, offering a reliable and efficient solution for removing contaminants. Regular purification of transformer oil significantly enhances transformer performance, extends service life, and reduces maintenance costs.

As electrical grid infrastructure continues to advance, transformer oil purification technologies are evolving to become more efficient, automated, and environmentally friendly. Investing in high-quality transformer oil purifier solutions, including advanced centrifuging machines, will be essential for ensuring the long-term reliability of power transformers.