What are the Types of Transformer Oil Filtration Machines?
Transformer oil is important for the smooth functioning and increased lifespan of electrical transformers. Over a period of time, materials such as moisture, gases, and dust particles can contaminate the oil, which can lead to transformers failing because of lower oil insulation properties. For restoring and purifying oil to its best state, transformer oil filtration machines are very important.
In this guide, we will cover the importance of transformer oil filtration machines, how these machines operate, the various types, and the most important criteria to consider before selecting one.
Table of Contents
Why Transformer Oil Filtration is Necessary?
In any power system, the transformer is a vital piece of equipment, and its oil is the lifeblood that keeps it running smoothly. Just like any other piece of machinery, a transformer has its components, and oil has two vital parts in the operation of transformers. It stretches the windings of the transformer through insulation and also keeps the transformer cool by getting rid of excess heat.
As years of service progress, transformer oil begins to lose its efficiency. It turns the oil into tiny particles of dust internally as well as exterior moisture, and it also draws in air. It begins to deplete, affecting the oil’s strength, efficiency and insulation, thereby increasing the chances of failure and breakdown of the internal machinery of the transformer.
A transformer oil filtration machine, or even using oil filtration methods themselves, can remove the tiny particles of dust, external moisture and air, thus maintaining the efficiency of the oil. It also, in a way, decreases the chances of the transformer oil breaking down and failing. Apart from that, using oil filtration methods can significantly reduce the chances of unexpected shutdowns and malfunctions.
Working Principles of Transformer Oil Filtration Machine
A transformer oil filtration machine works with a systematic procedure to eliminate harmful contaminants such as water, oil gases, sludge, and dirt particles. The goal is to enhance or refine the oil’s dielectric strength, thermal conductivity, and chemical stability. Different machines have different functionalities. Let’s discuss how oil filtration machines work.
- Pre-filtration (Particle Reduction)
The coarse filtration part of the process where the machine uses oil to scrape through mesh filters or to remove large solid particles, dirt, and dust into a sediment trap. This step is essential as it protects the downstream components.
- Heating (Reducing Viscosity)
When it comes to transformer oil, it thickens at lower temperatures. Controlled heating between 50 to 70 degrees Celsius helps reduce oil thickening and aids in the filtering process to a great extent. Some machines have a heating thermostat that ensures the oil is not degraded due to overheating.
- Vacuum Dehydration (Gas and Moisture Removal)
By placing oil under negative pressure using a vacuum chamber, it undergoes negative pressure, lowering the boiling point. This helps gases such as oxygen and nitrogen and moisture to evaporate. This oil-gas mixture is sometimes undesirable; therefore, in this step, the gas is removed by high-end machines during vacuum filtration.
- Fine Filtration (Micro-Purification)
Utilising high precision steam and electric centrifuging, the oil goes through ultra-fine filtration. Ultrasonic devices, electrostatic and centrifugal filters help in removing sub-micron particles, which is important for heavy-duty transformers.
- Polishing (Optional Final Stage)
In some critical cases, ultra-clean oil is generated using additional filters, chlorine, or adsorbent clay which removes oxidation byproducts in the oil. This oil complies with IEC 60422 standards.
- Recirculation & Quality Testing
Many of the filtration systems circulate the oil and filter it multiple times, which aids in thorough cleaning. In oil testing, built-in dielectric strength testers and Karl Fischer titration for moisture content are conducted prior to returning the oil to the transformer.
Using all of these stages, a transformer oil filtration machine can significantly increase the life of oil, improve the performance of a transformer, and even help in avoiding insulation failure. More modern and advanced models are built with automated systems which assist in monitoring the operation and in real-time control of the pressure, temperature, and even the levels of purity.
What are the Main Types of Transformer Oil Filtration Machines?
Different types of transformer oil filtration machines exist to fulfil various maintenance oil servicing, transformer maintenance, and operational constraints. Every type of transformer oil filtration machine ensures the removal of moisture, gases, and particles.
1. Single-Stage Transformer Oil Filtration Machine
The single-stage transformer oil filtration machine is the straightforward single option available. This machine is best for servicing smaller transformer oil. It is simple to use, cost-effective, and brings the oil to the required standard for use.
2. Double-Stage Transformer Oil Filtration Machine
The double-stage transformer oil filtration unit is best for heavily contaminated transformer oil. These machines are capable of catering to large power transformers and high voltage equipment. Double-stage transformer oil filtration machines are able to deliver the best results where oil quality is critical.
3. Mobile Transformer Oil Filtration Units
Mobile units are essentially transformer oil filtration systems on wheels, either mounted on trailers or trucks. These systems perform oil purification onsite, eliminating the need for heavy equipment transport to a servicing facility. This feature is beneficial in remote substations, wind farms, or industrial areas where downtime is heavily restricted. Mobile units can be single-stage or double-stage systems, depending on the purification requirements.
4. Online Transformer Oil Filtration Systems
An online transformer oil filtration machine is designated for operation while the transformer is continuously energised. Oil circulation for dehydration and filtration occurs without offline disconnection of the transformer. This is ideal for critical equipment in power plants, data centres, or continuous process industries that cannot afford any disruption. These systems are designed to manage oil quality in real time, proactively eliminating oil quality-related issues.
One can understand the difference between these systems and strategically choose the transformer oil filtration systems tailored to their maintenance policy, ensuring optimal transformer servicing reliability and enhanced transformer servicing life.
Factors to Consider to Choosing
Understanding how to select a transformer oil filtration machine involves much more than simply picking a design; it also involves determining how much care the transformer requires, the condition of the oil, and any operational constraints. A couple of factors, at the minimum, require consideration:
- Level of Contamination: Moisture, gas, or particle contamination in transformer oil helps determine the need for either a single or double-stage machine. Heavily contaminated oil requires deeper filtration and often a double-stage or specialised system.
- Transformer size and capacity: A larger transformer capable of storing more oil would require a machine that has a higher flow rate, while a continuous operating online system would suit a small to medium-sized transformer. These smaller and medium-sized transformers are often best maintained using compact, single-stage or mobile units.
- Maintenance Flexibility: Determine how much flexibility, besides mobile servicing, is provided for scheduled maintenance, for example, whether the machine requires servicing while online. Systems that allow continuous operation at the expense of the machine or transformer are preferable.
- Precision of Filtration: This refers to the vacuum capability of the machine, as well as the micron rating of the filters. High looking values are important as they help remove vital moisture and particles from high voltage or important transformers.
- Ease of Use and Maintenance: Simple and straightforward machines reduce time and operational errors. Daily operations can greatly benefit from features such as automated controls and monitoring sensors. Moreover, ease of moving the machine enhances daily operations and overall productivity.
Taking the maintenance and operational protocols into account, you are able to select a transformer oil filtration machine that actively restores oil quality and at the same time, maintains backup reliability and guaranteed safety for the transformers.
Investing in a quality transformer oil filtration machine ensures you have a transformer you can rely on. No matter what kind you decide on, be it a single-stage, double-stage, mobile or online system, the choice of machine should only be made after considering the degree of contamination, the system’s operational requirements, as well as available budget.
Regular oil filtration ensures an uninterrupted power supply, as it enhances performance and prevents costly failures. For optimal results, consult with industry expert manufacturer like Chinon Filtration to select the best filtration solution for your transformers.
