Category Archives: Fuller Earth

GlobeCore: Oil Purifier Protects Power Transformer and Extends Its Life by 20 Years

Globecore GmbH, a German company, manufactures oil purifier which  extends power transformer service life by 20 years.

Globecore protects and saves millions of dollars of investments in power transformers. This is achieved by transformer oil purification, which can be performed on site, with the transformer energized. Old oil is reused. Transformer oil is used in power and instrument transformers, as well as oil-filled switchgear. The oil insulates energized parts of the equipment, dissipates heat and extinguishes the arc in switches.

Transformer oil is used in power and instrument transformers, as well as oil-filled switchgear. The oil insulates energized parts of the equipment, dissipates heat and extinguishes arcs in switches.

What are the hazards of transformer oil contamination?

The transformer lives as long as its insulation system. Transformer gradually accumulates oxidation products, contaminants and other impurities over time when used. Oxygen and water in the insulating fluid provokes oxidation even under ideal operating conditions. Particles originating from the construction materials of the transformer are also a problem.

The process of oxidation results in formation of acids, which act on carbon and metals, forming aldehydes, alcohols and soap metals. These substances deposit on solid insulation. Contaminants increase oil viscosity, hampering circulation and cooling.

Therefore, aging of transformer oil is a consequence of combined effects of high temperature, oxygen, and electric field in the presence of the transformer construction materials. Important operational parameters of the insulating fluid (acidity, dissipation factor and dielectric strength) are very sensitive to its aging. The higher the intensity of the process, the sooner they reach critical levels, and the oil becomes impossible to use. Using such oil is also dangerous to the transformer: the risk of failures and power outages increases significantly.

What to do with used transformer oil?

Accumulation of waste transformer oil is a serious environmental concern. Consider this: over 40% of waterways in the world are contaminated and covered with a film of waste oil. One liter of waste oil makes a million liters of groundwater unusable! Plants and animals die due to massive pollution with oil products. Besides, waste oil contains carcinogenic substances. Dumping of waste oil into the environment is entirely unacceptable. So what is the solution and how to preserve the planet for future generations?

There is a solution: restoration of transformer oil to its initial condition and reusing the oil. Beside the pronounced environmental benefits, this solution allows to save on purchasing new and disposing of used oil, as well as to extend transformer lifetime by 20 years or more. At this time, the cost of one power transformer reaches, on average, hundreds of thousand US dollars. The number can easily reach into the millions, if the costs of disassembling the oil unit, transporting and installing a new transformer are factored in.

Transformer Oil Filtration Unit Globecore CMM-12R at electricity substation.

Transformer Oil Filtration Unit Globecore CMM-12R at electricity substation.

 

Methods of transformer oil purification

Let us consider several techniques used in filtration of used transformer oil.

Centrifuges. These devices are large drums in sealed cases. The drum consists of a number of conical plates with orifices. Centrifuges are used for removal of moisture and solid particles. At one time centrifuges were widely used in oil processing facilities despite their limitations, such as low capacity, complex design, intensive mixing of the processed oil with air and large footprint. With time, compact mobile units for oil treatment were developed, and the number of centrifuges operated is now on decline.

Electric purification. Electric purification is based on the uneven influence of the electromagnetic field on contaminants in transformer oil, which causes the impurities to settle on electrodes. The biggest limitation of this method is the complexity of cleaning the deposits from the electrodes. Also, electric purification cannot remove water. Due to these reasons, this approach has not been widely implemented  

Adsorption. This technique involves percolation of oil through a layer of adsorbent (silica gel in most cases), loaded into a vertical cylinder. Silica gel is produced by a series of chemical reactions, making the material rather expensive. Besides, there is a problem of silica gel disposal, since oil-contaminated materials must not be released into the environment.

The alternative is purification of transformer oil with Fuller’s earth, a natural adsorbent. Due to its porous structure, this material has good adsorptive qualities and can be used both for continuous regeneration of transformer oil from dehydrating breather filters, and also for restoration of oil drained from a transformer.

Generally, Fuller’s earth must somehow be disposed of, just like silica gel. However, GlobeCore process allows to reactivate and reuse the sorbent for transformer oil purification many times over.

Transformer Oil Degassing Cart. Oil Purifier.

Transformer Oil Degassing Cart

Thermovacuum dehydration and high vacuum degassing. The GlobeCore process using heat and high vacuum ensures the best parameters of transformer oil. Operation of these units is environmentally safe and does not involve special disposal or storage.    

GlobeCore environmental solutions

For many years, GlobeCore has been developing and implementing technologies for restoration of used transformer oil.

The company has successful experience in servicing power transformers of land based and offshore wind farms. We offer a range of units specifically tailored for these purposes.

The UVM type units degas oil and remove particulate matter by a combination of heat, vacuum and filtration. This unit reduces moisture content to 5 ppm and gas content to 0.1% or less and increases dielectric strength to 70 kV.

The CMM-R oil purification plants extend transformer lifetime by restoring the dielectric strength and chemical composition of transformer oil. This equipment allows to maintenance oil directly in an energized transformer. Connecting a CMM-R to an operating transformer allows to remove sludge from the windings and extract it from the oil by the sorbent. These units are loaded with Fuller’s earth.

Adsorbent Fuller’s Earth for Industrial Oil Purifier

Adsorbent Fuller’s Earth for Industrial Oil Purifier

 

The GlobeCore oil purification process has the capability of continuous processing of transformer oil, saving on new oil and disposal of saturated sorbents. Fuller’s earth can be reactivated up to 300 times, the equivalent of 1.5 – 2 years of operation or purification of 1000 tons of oil.

Zeolite drying cabinet GlobeCore ZSC-15

Zeolite drying cabinet GlobeCore ZSC-15

 

GlobeCore also cares about environmental safety of other machines which use adsorbents. The SSZ-15 zeolite drying cabinet can pre-dry zeolite to improve adsorption and the quality of oil dehydration. The CMM-4RP, one of GlobeCore latest developments, allows reactivation of saturated sorbents used in transformer oil filtration systems. The technology can reactivate the same sorbent at least 10 times. The reactivated sorbents contain no residual oil and, if necessary, can be disposed of a regular household waste without harm to the environment.

GlobeCore CMM-4-RP unit restores waste absorbent

GlobeCore CMM-4-RP unit restores waste absorbent

 

Therefore, GlobeCore transformer oil filtration technologies allow to:

  • save on purchasing new and disposing of used oil;
  • significantly lower industrial load on the environment;
  • extend transformer life by at least 20 years.

In conclusion, we would like to show some numbers to emphasize the economic feasibility of used transformer oil restoration:

  • average market price of restoring one liter of transformer oil is $0.7-0.8;
  • average price of one liter of new transformer oil is $1.5-2.
Globecore Oil Purifier CMM-12R

Globecore Oil Purifier CMM-12R

About GlobeCore:

Globecore Service center in Germany. dielectric Oil purifiers

GlobeCore is a manufacturing company researching, developing and producing various oil and fluid processing systems for use in several different industries worldwide and is the developer of the Power Transformer Service Life Extension Program and the GlobeCore Oil Filtration Process for servicing oil filled electric power transformers.

Globecore Service center in USA. dielectric Oil filtration

Contact Information:

GlobeCore GmbH

Edewechter Landstraße 173, Oldenburg-Eversten, Deutschland, 26131

www.GlobeCore.com

www.GlobeCore.de

Oil purifier

Globecore: Transformer oil maintenance

Globecore: Transformer oil maintenance

Is Fuller’s earth needed?

For Class III oils that are service aged, Fuller’s earth treatment will be required.  Color number, Acid Neutralization Number and Interfacial Tension are good indicators of the condition of Class III oils.  Fuller’s earth processing systems are available in a variety of configurations sized to the flow rate of the vacuum oil purifier.  They can be incorporated into the purifier system itself or provided as a separate module to be connected and used only when needed.

Fuller’s earth

Fuller’s earth can be used to decolorize and neutralize any petroleum oil, especially dielectric insulating oils.  It also excels in neutralizing traces of strong inorganic acids.  Due to the relatively large pores found in Fuller’s earth, it is well adapted to the removal of high molecular weight sulfonates, resins and asphaltines.

Transformer oil will discolor as oxidation takes place.  Color, by itself, is not a reliable test in evaluating the condition of the oil for further use.  It is however, a strong indication that something is happening within the transformer that requires investigation.  Once transformer oil changes from the yellow color range into the orange and red color range, it has degraded to the point where the vital parts of the transformer are being seriously affected.

As the color of the oil changes, sludge is forming in solution with the oil due to oxidation.  This causes a drop in interfacial tension and an increase in the acid (neutralization) number.  When transformer oil deteriorates to the red color ranges, deposited sludge continues to oxidize and harden, blocking vents and insulating cooling fins, causing higher operating temperatures.  Solid Insulation shrinkage may take place, and premature failure is likely.

Care

GlobeCore provides the service of Fuller’s earth filling and replacing in your equipment.  Care must be taken not to expose the Fuller’s earth to humid air or moisture.  This causes the clay to loosen its granular structure and can turn it to plain mud.  It is recommended that the clay be purchased in vapor-insulated bags to keep it dry.  For best performance and flow rate, oil should be supplied to the filters at a temperature of between 160 to 180 degrees F and a supply pressure capability of up to 80lbs. psi.

Leakage oil reclamation

Cost effective green solutions for facility oil reclamation

Total Lubrication Management provides efficient, environmentally friendly methods of reclaiming valuable lubricants on-site that minimize waste oil.  You receive bottom-line benefits from our abilities to:

  • Reduce new lubricant and oil purchases;
  • Support sustainability through oil conservation;
  • Decrease disposal liability;
  • Diminish environmental exposure and liability; and
  • Guarantee your oil cleanliness specifications are met

Environmental benefits

Total Lubrication Management stays ahead of the environmental curve through continuous review of EPA and safety regulations.  We make you aware of the latest updates as they apply to your specific operation.  And, we carry extensive liability insurance.  Even when it’s not practical or possible to slow down critical systems that need repair until the next scheduled outage, Total Lubrication Management can offer you a short or long-term rental of purification equipment to help you continue operating and address contamination issues without shutting down your operations.

The reclamation process

Sometimes it’s impractical to repair or control oil leaks if continued production is reliant on the subject equipment.  The Total Lubrication Management method of collecting and segregating leakage oil enhances your ability to restore the lubricant for continued use.  On-site waste oil is collected in dedicated storage via segregated waste streams, then purified by our experienced Total Lubrication Management technicians.  We work with your facility personnel to:

  • Identify high-lubricant use areas for reclamation;
  • Establish proper segregation, handling practices and purification using a variety of methods:;
    • First and second stage filtration
    • Centrifugal separation
    • Vacuum dehydration
    • Polishing filtration
    • On-site analysis
  • Create lubrication cleanliness/condition guidelines to ensure suitability for continued use;
  • Complete and verify that guidelines are met to your oil cleanliness specifications; and
  • Document the performance benefits.

Fuel oil filtration services

Process Details

Step 1:

Determine OEM Specifications for Fuel Cleanliness

Step 2:

On-site assessment of current Fuel Distribution

  1. Fuel analysis for cleanliness, water and bacteria
  2. Core samples of main storage tanks

Step 3:

Develop Comprehensive Blueprint

  1. Recommended actions based on test results may include
  2. Purification of current fuel to remove solids and water;
  3. Treatment of bacteria; and

iii. Storage tank preventive maintenance to remove accumulated contamination

  1. Initial Fill from delivery vehicle to storage tank;
  2. Distribution from storage tank to Mobile Fuel Trucks; and
  3. Distribution from Mobile Fuel Trucks to point of use

Step 4: Perform analysis and document Fuel Cleanliness ** Option for permanent installation of field equipment

In order to meet new air emission regulations, OEM’s have redesigned injector systems that require cleaner fuel to operate.  Utilizing unfiltered fuel can lead to injector failures resulting in poor performance, unplanned downtime, exceeding emission standards and high repair costs.

To make sure your equipment operates at peak performance, the filtration experts at Globecore can provide a comprehensive analysis of your fuel distribution – from transport delivery to use.  We will investigate the current condition of the fuel in the storage tanks and recommend corrective action if required.  We will develop a comprehensive filtration blueprint for fuel distribution throughout your facility that continuously meets or exceeds OEM requirements. As a result, you can operate your equipment with confidence.  On-site Inspection Provided by Filtration Experts Knowledgeable Globecore staff work with plant personnel to: *Recommend the best filtration for your application and establish fuel cleanliness specifications based on OEM recommendations.  *Present and distribute completed documentation to site management Globecore’s technicians arrive on-site to:

*Perform corrective action to current fuel/storage tanks if required;

*Coordinate installation of filtration units at various points throughout the fuel distribution system;

*Gather key baseline data for documentation; and

*Provide Service Summary that details the steps completed and any additional recommendations in ensuring long-term performance.

Globecore Filters provide these benefits:

*Continuously meet emission standards in properly maintained diesel equipment;

*Reduction in OEM filter usage and related costs;

*Reduction in repair expenses due to reduced wear and longer component life;

*Increased availability of manpower due to improved maintenance repair cycles; and

*Optimized equipment reliability.

Environmental Health and Safety:

Globecore routinely reviews EPA and safety regulations, including the latest updates as they apply to your specific operations.  In addition, Globecore carries extensive liability insurance.

Transformer Insulating Oil Market 2014-2018 Forecasts and Analysis

 

Texas, USA:  ReportsnReports.com has published “Transformer Oil Market 2014-2018” which provides “Forecast and Analysis” research in the transformer oil market.
Analysts forecast the global transformer oil market to grow at a Compounded Annual Growth Rate (CAGR) of 9.10 % during the period between 2013 and 2018.

The Report divides the global transformer oil market into three divisions: mineral-based transformer oil, bio-based transformer oil, and silicone-based transformer oil.  These are the type of products used to meet the demands of various end-user segments.

The “Global Transformer Oil Market 2014-2018” report has been prepared based on an in-depth market analysis with inputs from industry experts.  The report covers the North American, Europe and APAC regions.  it also covers the Global Transformer Oil market landscape and its growth prospects in the coming years.  The report also includes a discussion of the key vendors operating in this market.

According to the Report, the market driver is an increase in demand from developing countries and the main challenge is the possible adoption of dry distribution transformers.

The Report covers the following regions: North America, Europe and APAC.  Key vendors mentioned are Ergon Inc., Nynas AB and PetroChina Co. Ltd.  Other prominent vendors mentioned in the report are Apar Industries Ltd.,  Calumet Specialty Products Partners L.P., Cargill Inc., Dow Corning Corp. and San Joaquin Refining Co. Inc..

A summary of the report is attached below:

Source: PRWeb

Transformer oil acts as a dielectric medium in oil-filled transformers to cool and insulate the transformer windings and core.  The transformer windings and core, which are highly stable at high temperatures, are fully immersed in these oils as they prevent the contact of atmospheric oxygen with the cellulose paper insulation of the windings, which are highly prone to oxidization.  There are mainly three types of transformer oils: mineral-based, silicone-based, and bio-based.  Of these, mineral-based transformer oil is largely preferred mainly because of its good electrical and cooling properties and cost-effectiveness.

TechNavio’s analysts forecast the Global Transformer Oil market to grow at a CAGR of 9.10 percent over the period 2013-2018.

Covered in this Report

The Global Transformer Oil market can be segmented into three divisions: mineral-based transformer oil, bio-based transformer oil, and silicone-based transformer oil. These are type of products used to meet the demands of various end-user segments.

TechNavio’s report, the Global Transformer Oil Market 2014-2018, has been prepared based on an in-depth market analysis with inputs from industry experts. The report covers the North America, the Europe and APAC regions; it also covers the Global Transformer Oil market landscape and its growth prospects in the coming years. The report also includes a discussion of the key vendors operating in this market.

Key Regions

  • North Americas
  • Europe
  • APAC

Key Vendors

  • Ergon Inc.
  • Nynas AB
  • PetroChina Co. Ltd.

Other Prominent Vendors

  • Apar Industries Ltd.
  • Calumet Specialty Products Partners L.P.
  • Cargill Inc.
  • Dow Corning Corp.
  • San Joaquin Refining Co. Inc.

Market Driver

  • Increase in Demand from Developing Countries
  • For a full, detailed list, view our report.

Market Challenge

  • Adoption of Dry Distribution Transformers
  • For a full, detailed list, view our report.

Market Trend

  • Recovery of European Automotive Industry
  • For a full, detailed list, view our report.

Key Questions Answered in this Report

  • What will the market size be in 2018 and what will the growth rate be?
  • What are the key market trends?
  • What is driving this market?
  • What are the challenges to market growth?
  • Who are the key vendors in this market space?
  • What are the market opportunities and threats faced by the key vendors?
  • What are the strengths and weaknesses of the key vendors?

GlobeCore manufactures equipment for the servicing of transformers that includes oil regeneration, purification, and filtration systems featuring the GlobeCore Process!


See more video about transformer oil purification

Texas, USA:  ReportsnReports.com has published “Transformer Oil Market 2014-2018” which provides “Forecast and Analysis” research in the transformer oil market.
Analysts forecast the global transformer oil market to grow at a Compounded Annual Growth Rate (CAGR) of 9.10 % during the period between 2013 and 2018.

The Report divides the global transformer oil market into three divisions: mineral-based transformer oil, bio-based transformer oil, and silicone-based transformer oil.  These are the type of products used to meet the demands of various end-user segments.

The “Global Transformer Oil Market 2014-2018” report has been prepared based on an in-depth market analysis with inputs from industry experts.  The report covers the North American, Europe and APAC regions.  it also covers the Global Transformer Oil market landscape and its growth prospects in the coming years.  The report also includes a discussion of the key vendors operating in this market.

According to the Report, the market driver is an increase in demand from developing countries and the main challenge is the possible adoption of dry distribution transformers.

The Report covers the following regions: North America, Europe and APAC.  Key vendors mentioned are Ergon Inc., Nynas AB and PetroChina Co. Ltd.  Other prominent vendors mentioned in the report are Apar Industries Ltd.,  Calumet Specialty Products Partners L.P., Cargill Inc., Dow Corning Corp. and San Joaquin Refining Co. Inc..

A summary of the report is attached below:

Source: PRWeb

Transformer oil acts as a dielectric medium in oil-filled transformers to cool and insulate the transformer windings and core.  The transformer windings and core, which are highly stable at high temperatures, are fully immersed in these oils as they prevent the contact of atmospheric oxygen with the cellulose paper insulation of the windings, which are highly prone to oxidization.  There are mainly three types of transformer oils: mineral-based, silicone-based, and bio-based.  Of these, mineral-based transformer oil is largely preferred mainly because of its good electrical and cooling properties and cost-effectiveness.

TechNavio’s analysts forecast the Global Transformer Oil market to grow at a CAGR of 9.10 percent over the period 2013-2018.

Covered in this Report

The Global Transformer Oil market can be segmented into three divisions: mineral-based transformer oil, bio-based transformer oil, and silicone-based transformer oil. These are type of products used to meet the demands of various end-user segments.

TechNavio’s report, the Global Transformer Oil Market 2014-2018, has been prepared based on an in-depth market analysis with inputs from industry experts. The report covers the North America, the Europe and APAC regions; it also covers the Global Transformer Oil market landscape and its growth prospects in the coming years. The report also includes a discussion of the key vendors operating in this market.

Key Regions

  • North Americas
  • Europe
  • APAC

Key Vendors

  • Ergon Inc.
  • Nynas AB
  • PetroChina Co. Ltd.

Other Prominent Vendors

  • Apar Industries Ltd.
  • Calumet Specialty Products Partners L.P.
  • Cargill Inc.
  • Dow Corning Corp.
  • San Joaquin Refining Co. Inc.

Market Driver

  • Increase in Demand from Developing Countries
  • For a full, detailed list, view our report.

Market Challenge

  • Adoption of Dry Distribution Transformers
  • For a full, detailed list, view our report.

Market Trend

  • Recovery of European Automotive Industry
  • For a full, detailed list, view our report.

Key Questions Answered in this Report

  • What will the market size be in 2018 and what will the growth rate be?
  • What are the key market trends?
  • What is driving this market?
  • What are the challenges to market growth?
  • Who are the key vendors in this market space?
  • What are the market opportunities and threats faced by the key vendors?
  • What are the strengths and weaknesses of the key vendors?

GlobeCore manufactures equipment for the servicing of transformers that includes oil regeneration, purification, and filtration systems featuring the GlobeCore Process!


See more video about transformer oil purification

How to Improve the Reliability of Electric Power Equipment with the Correct Transformer Oil

[:en]

Transformer oils have certain technical and chemical parameters. These parameters define the scope of the oil’s applications and use.

The “Dissipation Factor” is one of the most important indications of oil quality and is a measure of the oil’s dielectric strength.  Aging causes oil to lose its performance capabilities and poses a threat to the safe operation of oil filled equipment.  Dielectric strength testing is a safety concern and must never be neglected.

The actual dielectric strength of the oil is mostly affected by the presence of solid particles, moisture, and other contaminates.  It is therefore, important to remove solid particles, water and other contaminates from transformer insulating oil to maintain the operating performance of the oil.  The best way to ensure the purity of your transformer oil is to use the GlobeCore Process performed by one of its various oil purification or oil regeneration units.

Another performance characteristic of oil is the oil’s viscosity rating.  An oil’s viscosity rating indicates the oil’s “resistance to flow” or “speed of flow” as measured through a viscometer.  The viscosity, or thickness of the oil can also affect the oil’s ability to transfer heat and cool the transformer.

Setting temperature and flashpoint temperature both help to indicate the allowable range of oil operation.  A “Low Setting” temperature is important when the oil is used in extremely cold climates.  A high oil flashpoint is important for reducing the potential fire safety concerns.

Another important quality of the oil is its oxidation stability, i.e. the ability to maintain its properties during prolonged use.  Oxidation stability is influenced by many factors, both internal such as antioxidant additives, reaction with metals, formation of gases in the oil, etc., and external factors such as moisture, air and temperature.  This parameter is important for the service life of both the oil and oil filled equipment.

Many oils, e.g. GK and TKp contain antioxidant additives which can extend the service life of oil to as long as 20-25 years.

Purchasing transformer oil from manufacturers and traders is not a problem these days.  Each company is competing and attempting to sell at the lowest price and offer the best service.

Transformer oil is an indispensible part of the insulation system of electric power transformers and other electrical equipment.  High purity and low viscosity are key in allowing your selected oil to be used in electric power transformers.

Depending on the actual equipment, transformer oils function as a dielectric liquid or, for instance, as an arc-extinguishing media in switching devices.

Quality oil has high dielectric strength, a low setting point, a high flash point, high oxidation stability, and the availability of convenient and practical transportation vessels.  High quality oil significantly extends reliable operation of oil filled electric equipment.

 

Above all, the oil in transformers and electrical equipment must be kept clean and free from moisture in order to provide the best possible service to your electrical equipment and prevent the need for unscheduled maintenance events.

It’s time to get with the Process.  The GlobeCore Process!

 


See more video about transformer oil purification
[:de]

Transformer oils have certain technical and chemical parameters. These parameters define the scope of the oil’s applications and use.

The “Dissipation Factor” is one of the most important indications of oil quality and is a measure of the oil’s dielectric strength.  Aging causes oil to lose its performance capabilities and poses a threat to the safe operation of oil filled equipment.  Dielectric strength testing is a safety concern and must never be neglected.

The actual dielectric strength of the oil is mostly affected by the presence of solid particles, moisture, and other contaminates.  It is therefore, important to remove solid particles, water and other contaminates from transformer insulating oil to maintain the operating performance of the oil.  The best way to ensure the purity of your transformer oil is to use the GlobeCore Process performed by one of its various oil purification or oil regeneration units.

Another performance characteristic of oil is the oil’s viscosity rating.  An oil’s viscosity rating indicates the oil’s “resistance to flow” or “speed of flow” as measured through a viscometer.  The viscosity, or thickness of the oil can also affect the oil’s ability to transfer heat and cool the transformer.

Setting temperature and flashpoint temperature both help to indicate the allowable range of oil operation.  A “Low Setting” temperature is important when the oil is used in extremely cold climates.  A high oil flashpoint is important for reducing the potential fire safety concerns.

Another important quality of the oil is its oxidation stability, i.e. the ability to maintain its properties during prolonged use.  Oxidation stability is influenced by many factors, both internal such as antioxidant additives, reaction with metals, formation of gases in the oil, etc., and external factors such as moisture, air and temperature.  This parameter is important for the service life of both the oil and oil filled equipment.

Many oils, e.g. GK and TKp contain antioxidant additives which can extend the service life of oil to as long as 20-25 years.

Purchasing transformer oil from manufacturers and traders is not a problem these days.  Each company is competing and attempting to sell at the lowest price and offer the best service.

Transformer oil is an indispensible part of the insulation system of electric power transformers and other electrical equipment.  High purity and low viscosity are key in allowing your selected oil to be used in electric power transformers.

Depending on the actual equipment, transformer oils function as a dielectric liquid or, for instance, as an arc-extinguishing media in switching devices.

Quality oil has high dielectric strength, a low setting point, a high flash point, high oxidation stability, and the availability of convenient and practical transportation vessels.  High quality oil significantly extends reliable operation of oil filled electric equipment.

 

Above all, the oil in transformers and electrical equipment must be kept clean and free from moisture in order to provide the best possible service to your electrical equipment and prevent the need for unscheduled maintenance events.

It’s time to get with the Process.  The GlobeCore Process!

 


See more video about transformer oil purification

Which kind of Transformer Oil Should where to buy transformer oil?

where to buy transformer oil

A great number of manufacturers and distributors of transformer oils operate in international and national markets.

Transformer insulating oil is a dielectric liquid that is intended for cooling and insulating electric power transformers and other high voltage equipment.  Transformers remain an indispensible part of the electric power generation and transmission industry.

In scientific terms, transformer oil is a product of crude oil refining.  The performance properties of transformer oil depend heavily on the quality and parameters of the raw material.  The performance of the oil is defined by the positive and negative properties of the crude oil.  Chemical composition of oil is quite complex.  It includes the following components: paraffin (10-15%), naphtenes or cycloparaffins (60-70%), aromatic hydrocarbons (15-20%), asphalt (1-2%), sulfuric compounds (<1%), nitric compounds (<0.8%), naphtenic acids (<0.02%) and antioxidation additive (0.5 – 0.5%).

Transformer oils must be highly resistant to oxidation and must not form sludge or emulsify when coming in contact with water.  Anti-oxidation additives are an important component and can be found in virtually all types of transformer oil.  When selecting an oil for your equipment, be sure to look for oils that have good antioxidant additives included since they will inhibit the oxidation process considerably better than uninhibited oils.

The efficiency of such additives is based on the ability of the additives to react with active peroxide radicals that form as the result of hydrocarbon oxidation reaction and are the primary carriers.  The presence of additives in transformer insulating oils slows the aging of the oil.  As soon as the additive is depleted, the oil ages in about the same amount of time as an oil without the the antioxidant additives.  Without the additives, the oil aging process will accelerate.

Two of the main characteristics of transformer oil are its viscosity and density.  These have a pronounced affect on the function of the oil.  Higher viscosity may mean better dielectric strength, but may reduce the ability of the oil to transfer heat and cool the transformer.  Optimal kinetic viscosity of the oil at 20 ̊C is about 28-30×10-6 m2/second.

The oil’s “Dissipation Factor” is responsible for the oil’s dielectric properties and protects the transformer’s electrical system from possible short circuits.

These and the other characteristics of transformer oil are improved by the use of high quality crude oil, deep refining and introduction of additives that increase the oil’s oxidation stability and reduce corrosion.

where to buy transformer oil

where to buy transformer oil

When oil is significantly oxidized due to the influence of water, solids, air and other gases, and high temperatures, the oil should be replaced.  If the degradation of the oil’s properties is not detected in time, transformers can and will fail.  When oil decays, it can no longer serve as a dielectric insulator and starts to react with the metal of the transformer tank and hinders cooling and may lead to short circuits.

The following are some of the different kinds of oils that may be purchased in the local market:

VG type oil is made from paraffinic crude oil by a catalytic process with the addition of an antioxidant  additive.  It is a good dielectric and is rather stable against oxidation.  It is mostly used in higher voltage equipment.

GK type oil is made of sulfuric paraffinic oils by hydrocracking.  It also contains ionol, an antioxidant, that ensures good stability and dielectric properties of the oil.  It is another kind of oil used in higher voltage systems.

TKp oil is made from low-sulfur naphtenic crude by an acid-alkali purification process.  The oil also contains antioxidant additives.  This oil is recommended for equipment with voltage up to 500 kV.

Oil selection depends not only on the type of electric equipment you are using, but also on the individual requirements of the facility.  Most of transformer oils are universal.  In all cases, the correct selection of oil type with consideration of local climatic and physical operating conditions ensures reliable and stable operation of electric power equipment such as high voltage transformers and switch gear.

See more video about transformer oil purification

Quality Assurance: Methods of Transformer Oil Testing

Transformer Oil Testing Methods Value.

Transformer Oil Testing is a proven loss prevention technique which should be a part of any condition based predictive maintenance program. This early warning system can allow maintenance management to identify maintenance priorities, plan work assignment schedules, arrange for outside service, and order necessary parts and materials. GlobeCore uses test results to diagnose transformer problems.
The transformer’s fluid not only serves as a heat transfer medium, it also is part of the transformer’s insulation system. It is therefore prudent to periodically perform tests on the oil to determine whether it is capable of fulfilling its role as an insulant. Some of the most common tests for transformer oil are: Dissolved Gas In Oil Analysis, screen tests, water content, metals-in-oil, and polychlorinated biphenyl
(PCB) content. In this article, we will examine the value and benefits of each test.

transformer oil testing methods ASTM Method Significance of Transformer Oil Testing Method Units
Color D1500 Used to observe darkening of the oil by comparing it to previous samples of oil from the same transformer. Transformer oil colour is determined by means of transmitted light and given a numerical value (0-5) based on comparison with a series of color standards. Noticeable darkening oil indicates either contamination or that arcing is taking place. 0-5
Dielectric breakdown voltage D877 Measures the voltage at which the oil fails electrically, which is indicative of the amount of contaminant (usually moisture) in the oil. The dielectric breakdown voltage is measured by applying a voltage between two electrodes under the oil. New oil should have a minimum dielectric strength of 35 kV by ASTM Transformer Oil Testing Methods. kV
Dissolved gas analysis (DGA) D3612 Identifies various gas ppm levels that are present in transformer insulating oil. Different gasses will dissolve in the oil that indicate various types of thermal and electrical stress occurring within the transformer. An oil sample tube and syringe is used to draw, retain and transport the oil sample in the same condition as it is inside a transformer with all fault gases dissolved in it. ppm
Dissolved metals D7151 Identifies any dissolved metals that could originate from overheating or arcing and a portion of the particulate metals that may originate from mechanical wear. Measured by inductively coupled plasma atmonic emission spectrometry (ICP-AES) and expressed in micrometers. µm
Flash point, fire point D92 Indicates the volatility of insulating oil by measuring the minimum temperature at which the heated oil gives of sufficient vapor to form a flammable mixture with air. °C
Interfacial tension D971 Measures the presence of soluble contaminants and oxidation products in transformer oil. Expressed in mN/m, it is a test of interfacial tension of water against oil, which is different from surface tension in that the surface of the water is in contact with oil instead of air. A decreasing value indicates an increase in contaminants and/or oxidation products within the oil. mN/m
Furanic compounds D5837 Determines the presence of degradation in cellulosic materials such as paper, pressboard, and cotton, which generate furanic compounds in the insulating oil. Measurements are made using high-performance liquid chromatography (HPLC). ppb
Moisture (Water) Content D1533 Measured in parts per million (ppm) using the weight of moisture divided by the weight of oil. Moisture content in oil lowers the insulating system dielectric strength and allows flashover that can damage a transformer. For mineral oil, a generally accepted maximum moisture content is 35 ppm. This test does not measure the water content in the transformer paper insulation. ppm
Neutralization (Acid) number D974 New transformer oils contain practically no acids. The acidity test measures the content of acids formed by oxidation and contaminates. Measurements are made by the amount of potassium hydroxide (KOH in mg) required to neutralize the acid in one gram of oil. Typically, results of 0.10 mg KOH/gram of oil or less are considered good. Higher values are indicative of a problem. mg KOH/g
Oxidation inhibitor content D2668 Measures the amount of 2,6-ditertiary-butyl paracresol and 2,6-ditertiary-butyl phenol that has been added to new insulating oil as protection against oxidation. In a used oil it measures the amount remaining after oxidation has reduced its concentration. %
Polychlorinated biphenyls (PCB) content D4059 Detects the concentration level of polychlorinated biphenyls in transformer oil by gas chromatography. Measured in ppm, it also applies to the determination of PCB present in mixtures known as askarels. ppm
Pour point D97 Indicates the lowest temperature at which the insulating oil will flow. This test is particularly useful in cold climates to ensure that the oil will circulate and serve its purpose as an insulating and cooling medium. °C
Power Factor D924 Indicates the dielectric losses of the oil, or energy that is dissipated as heat. Useful for measuring changes within the insulating oil resulting from contamination or deterioration. The power factor of insulating oil equals the cosine of the phase angle between an ac voltage applied and the resulting current. For mineral oil, the power factor of new oil should not exceed 0.05 percent at 25 degrees C. %
Relative density (specific gravity) D1298 Determines the density, relative density (specific gravity), or API gravity of transformer oil by use of hydrometer at a reference temperature. A high specific gravity indicates the oil’s ability to suspend water. In extremely cold climates, specific gravity can be used to determine whether ice will float on the oil. number
Resistivity D1169 Measures the electrical insulating properties of transformer oil under conditions comparable to those of the test. A low resistivity reflects a high content of free ions and ion-forming particles in the insulating oil, and normally indicates a high concentration of conductive contaminates. ohms
Visual examination D1524 Oil is visually examined by passing a beam of light through it to determine transparency and identify foreign matters. Contamination of the oil is exhibited by poor transparency, cloudiness, or the observation of foreign particles. Bright, dark, clear of particles etc.

See bigger list of transformer oil testing methods in the end of the article.

The performance characteristics of transformer insulating oil are monitored and tested at several stages during its service life.  Regular monitoring of the oil’s quality and condition is a part of the process of servicing electric power equipment. The condition of the oil, its purity and contamination level will greatly help in indicating the condition of the transformer’s solid insulation.  It is therefore, essential to the life of the transformer to periodically monitor the condition of the insulating oil.  The heart of the transformer is the solid insulation, but the insulating oil is the life blood of the transformer.  Without the life blood, the heart will die.

The ability of insulating oil to maintain its original performance characteristics during long term operation of electric equipment is referred to as “oil stability.”  If the electric power equipment has no defects and operates in accordance with design and expectations, the performance characteristics of new oil will change and degrade slower.  When new, transformer oil has a very light color and complies with performance standards that include dielectric strength and other important characteristics.  During the course of the oil’s service life, the stability of the oil decreases and visible changes occur and oil’s color slowly becomes darker and darker.

Contaminated oil usually has a high ash content, increased acidity and presence of low molecular acids.  Acidic sludge forms in contaminated oil and aggressively attacks the cellulose insulation and reacts with the metals of the transformer’s other internal components.

transformer oil testing methods

Timely oil monitoring and oil analysis programs can identify when the oil needs to be changed or serviced through an oil purification and/or oil regeneration process.  Servicing the oil before it becomes aggressive against the solid insulation is the key to extending the service life of your transformers.

The main physical and chemical properties tested in Transformer Oil Testing Methods are the oil’s dielectric strength, dissipation factor, flashpoint, color, amount of solid particulate matter, water content, gas content and the oil’s acid number.

transformer oil testing methods

Dielectric strength is one of the most important indications of oil stability and this is often the first test performed.  The “dielectric breakdown test” is calculated as an average of five breakthroughs achieved in a standard discharger with two electrodes submersed in the oil at 2.5 mm distance from each other.  Six breakthroughs are achieved in the test and the last five are averaged.  If the oil is fresh, the lowest allowable breakthrough voltage is 30 kV.  In some transformers, that meets the minimum operating standard.

Decreasing dielectric strength is caused by contamination of the oil by gas, moisture, cellulose fibers or other particulate matter.

A similar process is used to calculate the oil’s “dissipation factor.”  It is the the oil’s ability to neutralize energy, prevent breakthroughs and cool the transformer.   It is a characteristic of the oil’s quality and purity and acidity.  In general, an increased dissipation factor means degradation of the oil’s dielectric capabilities.


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The color of transformer oil changes from light yellow to cloudy brown under the influence of temperature, contaminants and electric current.  The color is not in itself an indication of any specific problem, but a dark color is usually an indication of aged and/or contaminated oil.

Transformer Oil Testing Methods

  • Color; e.g., ASTM D1500
  • Dielectric breakdown voltage; e.g., D 877, ASTM D1816
  • Dissolved gas analysis; e.g., ASTM D3612
  • Dissolved metals; e.g., ASTM D7151
  • Flash point, fire point; e.g., ASTM D92
  • Interfacial tension; e.g. D 971
  • Furanic compounds; e.g., ASTM D5837
  • Karl Fischer moisture; e.g., ASTM D1533
  • Liquid power factor; e.g., ASTM D924
  • Neutralization number; e.g., ASTM D974
  • Oxidation inhibitor content; e.g., ASTM D2668
  • Polychlorinated biphenyls content; e.g., ASTM D4059
  • Relative density (specific gravity); e.g., D 1298, ASTM D1524
  • Resistivity; e.g., ASTM D1169
  • Visual examination; e.g., ASTM D1524

The presence of solid particles in the oil and the acid number of the oil are two related oil purity characteristics.  Unsolved materials accumulated in the oil in the form of sludge or suspended particles (fibers, dust, solved paint, metal particles, ash etc) degrade the oil’s dielectric properties and promote oil oxidation.  The more particles that are present in the oil, the faster the oil ages. The acid number is expressed as milligrams of KOH required to neutralize all acids in a gram of oil and indicates the degree of oil aging.  A normal and acceptable acid number is 0.25 mg KOH/g, while the limit of contaminant content is 515 parts per million (ppm).

Moisture and gas content in transformer oil must be tested for thoroughly.  Water and gases are very damaging to your transformer insulation system and are two main cause of the oxidation process and oil aging process.

Moisture and water content is measured as amount of hydrogen when reacting the oil with calcium hydride in a certain period of time.  Gas content is measured by an absorptiometric analyzer or a chromatographer.

transformer oil before and after testing the purification methods

The oil’s flashpoint and the oil’s setting point are two indications of the general fire safety of the oil and the oil’s ability to operate in adverse temperature conditions both hot and cold.

The are distinct advantages of testing and analyzing transformer oil before starting your electric power equipment and during scheduled maintenance events.  Oil testing allows the operator to determine the equipment’s operating efficiency, conditions and the possibility of future malfunctions.  If the purity and quality standards are followed, the equipment will be less likely to experience failures and downtime and unscheduled maintenance and repair costs.

Insulation overheating

The paper insulation which is normally used to insulate the windings of a transformer is a cellulose product. If a transformer becomes overloaded for any reason, the windings will generate more heat and deteriorate the cellulose insulation. So, insulation overheating measurement is also transformer oil testing methods. A DGA test can identify an overloaded transformer by a test result showing high carbon monoxide, high carbon dioxide, and in extreme cases, even elevated methane and ethylene.

If a transformer is overloaded for a long period of time, the deteriorating condition of the cellulose will shorten the life of the transformer. When the cellulose insulation breaks down to the point where arcing starts to occur, the transformer must be taken out of service.

Insulation Liquid Overheating

Overheating of the liquid insulation is a slightly different problem in transformers and can be on of transformer oil testing methods. A DGA test will indicate high thermal gases (methane, ethane and ethylene) as a result of overheating of the liquid.

These gases are formed from a breakdown of the liquid caused by heat. Heating may be caused by poor contacts on a tap changer, or loose connections on a bushing or a grounding strap, or circulating currents in the core due to an unintended core ground.

Actions that can be taken once a thermal gas problem is detected would depend on the severity of the problem. If conditions are not severe, the transformer should be monitored closely. If conditions gets worse, and thermal combustibles elevate, the transformer will need to be taken out of service. If the combustibles are stable and remain present, the transformer should be inspected at the next outage or downtime scheduled.

Corona

Corona is considered to be partial discharge and occurs at areas of high electrical stress, such as at sharp points along an electrical path. Partial discharge is commonly explained as being intermittent

Arcing

Arcing is the most severe condition in a transformer because it indicates a breakdown of the insulation.

The presence of acetylene is an indicator of arcing and so it’s one of the most important transformer oil testing methods; and even low levels of this gas should cause concern.

Normally, arcing occurs only after other problems surface which show up through DGA testing.

However, the high energy required to produce an arc will cause all combustibles to be elevated. If the arc occurs in the area of cellulose insulation, carbon dioxide and carbon monoxide also will be elevated.

Arcing can be generated in many areas of a transformer. Insulation breakdown in the windings, from coil to coil or coil to ground, will result in arcing. A portion of the insulation may deteriorate until it can no longer contain the stress of the electrical conductor. If a winding shorts from turn to turn, or phase to phase, or phase to ground, arcing will occur and the transformer will fail. When arcing occurs in the area of the windings, the usual result is de-tanking of the transformer, and a rewind conducted. A loose connection also may cause arcing, but of greater significance would be arcing due to insulation breakdown.

Screen Testing

The “screen test” is a collection of physical, electrical and chemical transformer oil testing methods. These tests include dielectric breakdown, power factor, inter-facial tension, acidity, and color. A larger quantity of oil is needed for these tests. To gather the sample, a clean, moisture free container must be used — typically a 1 liter glass bottle. Each test is an indication of how suitable the insulation liquid is for service.

No single test alone will represent or indicate the true condition of the liquid. Therefore, it is suggested that they all be performed.

Summary

Transformer Oil Testing Methods are key part of any maintenance program. An annual DGA is the most important test for liquid insulation. Analysis of gases in the oil can indicate insulation overheating/overloading, liquid overheating, partial discharge (corona), or arcing in the transformer. The screen test is a collection of additional physical, electrical and chemical tests, including: dielectric breakdown, power factor, interfacial tension, acidity and color. No single test alone will indicate the true condition of the liquid, so all the screen tests should be performed. Additional useful tests performed by transformer oil laboratories include those for water content, PCBs furanic compounds and metals-in-oil.

Classification of New Transformer Insulating Oil Testing

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The conditions in which insulating oil is used in transformers, switches, and other high voltage equipment are rather demanding on the performance characteristics of the insulating oil.  During the service life of the oil, it is heated by currents, contaminated by particles of solid insulation and chemical reactions with the internal surfaces of the equipment.  Each of these separately and together significantly accelerate the aging of transformer oil and can make the oil harmful to the equipment.  This is especially true with regards to the transformer insulating paper.

A sample of transformer oil is taken from the lower part of the transformer oil tank after rinsing the drain opening with oil.  The sampling vessel must be clean and very dry or the testing results will not reflect the true condition of the oil being tested.

Local and international standards define certain parameters by which the oil must comply.  Oil analysis and testing should be performed directly before placing oil into the electric power equipment.

New transformer oil is also tested before being placed into transformers.  The purity and quality guaranteed by the manufacturer of the oil does not prevent water, air and solid particles from entering the oil during handing and storage.  You cannot assume that the new oil is free from contaminates and moisture.  The oil must be properly analyzed immediately prior to use to ensure the proper operation of your electrical equipment

Before a transformer is energized, the oil in the transformer must be briefly tested for minimum dielectric strength levels, solid particulate matter, acidity and flashpoint.  If different brands of oil are used in the transformer, the final blend must be tested for stability.  The blended oil fill should not be inferior in stability to any of the separate oils with the lowest stability value.

Used oil must be tested according to standards that have been set for the operation of industrial equipment that it will be used in.

Before testing, the vessel, containing the oil sample, is inverted and turned slowly around several times to eliminate air bubbles from the oil sample.  A ceramic oil test vessel with electrodes is filled three times.  Oil is poured on the walls of the vessel in a thin stream so as to prevent formation of air bubbles.  The level of oil in the vessel must be at least 15 mm higher than the top of the electrodes.

Transformer oil is allowed to settle in the vessel for 15-20 minutes for air bubble removal.  The voltage is then gradually increased at the rate of 1 – 2 kV per second.  After a breakthrough is achieved (spark between the electrodes), voltage is recorded and then dropped to zero.  Six tests are performed and the average of the last five tests is taken.  The first breakthrough is not averaged in since it was only performed as a guide.

After each breakthrough, carbon particles are removed from the space between the electrodes by clean glass or metal rods.  The liquid is then allowed to settle for 10 minutes before performing the next test.

The transformer oil sampling process will vary from facility to facility depending on the equipment used and purity requirements of the equipment and oil being tested.

At any rate, a timely oil analysis program may well prevent significant costs and losses for your company.

See more video about transformer oil purification
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The conditions in which insulating oil is used in transformers, switches, and other high voltage equipment are rather demanding on the performance characteristics of the insulating oil.  During the service life of the oil, it is heated by currents, contaminated by particles of solid insulation and chemical reactions with the internal surfaces of the equipment.  Each of these separately and together significantly accelerate the aging of transformer oil and can make the oil harmful to the equipment.  This is especially true with regards to the transformer insulating paper.

A sample of transformer oil is taken from the lower part of the transformer oil tank after rinsing the drain opening with oil.  The sampling vessel must be clean and very dry or the testing results will not reflect the true condition of the oil being tested.

Local and international standards define certain parameters by which the oil must comply.  Oil analysis and testing should be performed directly before placing oil into the electric power equipment.

New transformer oil is also tested before being placed into transformers.  The purity and quality guaranteed by the manufacturer of the oil does not prevent water, air and solid particles from entering the oil during handing and storage.  You cannot assume that the new oil is free from contaminates and moisture.  The oil must be properly analyzed immediately prior to use to ensure the proper operation of your electrical equipment

Before a transformer is energized, the oil in the transformer must be briefly tested for minimum dielectric strength levels, solid particulate matter, acidity and flashpoint.  If different brands of oil are used in the transformer, the final blend must be tested for stability.  The blended oil fill should not be inferior in stability to any of the separate oils with the lowest stability value.

Used oil must be tested according to standards that have been set for the operation of industrial equipment that it will be used in.

Before testing, the vessel, containing the oil sample, is inverted and turned slowly around several times to eliminate air bubbles from the oil sample.  A ceramic oil test vessel with electrodes is filled three times.  Oil is poured on the walls of the vessel in a thin stream so as to prevent formation of air bubbles.  The level of oil in the vessel must be at least 15 mm higher than the top of the electrodes.

Transformer oil is allowed to settle in the vessel for 15-20 minutes for air bubble removal.  The voltage is then gradually increased at the rate of 1 – 2 kV per second.  After a breakthrough is achieved (spark between the electrodes), voltage is recorded and then dropped to zero.  Six tests are performed and the average of the last five tests is taken.  The first breakthrough is not averaged in since it was only performed as a guide.

After each breakthrough, carbon particles are removed from the space between the electrodes by clean glass or metal rods.  The liquid is then allowed to settle for 10 minutes before performing the next test.

The transformer oil sampling process will vary from facility to facility depending on the equipment used and purity requirements of the equipment and oil being tested.

At any rate, a timely oil analysis program may well prevent significant costs and losses for your company.

See more video about transformer oil purification

Transformer Oil Storage Tanks

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In power transformers and in electric equipment in general, oil is used to insulate and to cool.  The use of various types of oil for power systems is governed by internationally recognized standards.  The purpose of the uniform standards is to keep electric power equipment and systems in good working condition.  Of course, this depends on the performance characteristics and general condition of the transformer insulating oil.

Any business that uses oil must be concerned with the issue of oil storage and disposal.  This is especially important for the energy sector and the electric power generating and transmission industry.

Transformer insulating oil may come from the factory or substation in more than one condition.  Even when the oil is fresh from the manufacturer, it is possible that undesirable amounts of moisture and gases accumulated in the oil during transportation.  Transformer oil delivered from the manufacturer and purified to comply with the performance standards is usually stored in liquid storage tanks at maintenance facilities.  Regardless of the condition of the oil, whether it is new or used, it must be stored in a safe and leak proof container.

For the purposes of fire safety, the manufacturer must strictly adhere to national safety and fire prevention standards.  The actual method of storage however, and the availability of specially equipped buildings, tanks, and service equipment can vary greatly depending on location, climate and country.

A wide range of different oil storage tanks can be found in the local and international markets.  There are soft tanks that can drain and store oil more quickly reducing transformer servicing and possible downtime.  But, these types of tanks are better suited for transporting oil to interim storage facilities.

For actual storage of liquids, the most widely used tanks are vertical cylindrical tanks that are equipped with leveling quality controls, agitation systems, temperature sensors and built-in maintenance systems.

A vertical insulated tank is made of steel with heated circulation pipes below the surface.  For tank maintenance and servicing, a ladder is mounted on the tank with a protective rail along the top. Temperature is monitored by a thermistor installed in the bottom of the tank that displays the temperature on the tank’s control panel.  The heat exchange system is made of an array of pipes and insulation jackets.

Proper oil storage systems should be designed to keep the oil in good condition and preserve the oil’s performance characteristics.   Proper stored oil maintenance will help in eliminating the costs associated with additional purification and regeneration due to premature aging of the oil while being stored before use in your electric power equipment.

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Methods of Transformer Oil Purification

Transformer Oil Purification

Oil purification methods

Transformer oil serves to insulate the energized parts and components of electric power transformers and also acts as a heat transfer medium.  Additionally, it  protects the solid insulation from damaging moisture.  Besides transformers, insulting oil is used in switches, high voltage capacitors and power cables.  In switches, the oil acts as an arc extinguisher preventing fires and possible explosions.

oil purification methods

oil purification methods

Over the course of the transformer’s service life, that may span many years of operation, the insulting oil will accumulate various contaminants that adversely affect the oil’s performance characteristics.  Once the insulating oil’s performance characteristics have been diminished, the transformer’s solid insulation will be in greater risk of failure.  In order to restore them, the oil must be purified of foreign substances and contaminates (water, gases and solid particles).  Today, we’d like to look into the methods of transformer oil purification.  Different methods of purification can be used depending on the substance(s) that need to be removed from the oil.

Centrifugal purification is a method for water removal.  It separates unwanted materials, including water and moisture, under centrifugal force.  The main advantage of this method is the relatively high rate of water removal.  There are however, several drawbacks to this method that include; (1) a low degree of overall purification of the oil; and (2) complexity and the necessity for constant presence of service personnel supervising the process.

Another method for water removal is adsorption purification.  The biggest advantage of this method is its simplicity.  The drawbacks are: (1)  the dependency of the purification rate on the type of sorbent used; (2) the need to dispose of used sorbent and the potential environmental risks; and (3) the high quality requirement to input oil and the low rate of processing capacity.

The difference between he boiling point of water and oil is the essence of thermovacuum drying. The oil to be purified goes into a special chamber with low pressure.  In such conditions water evaporates at room temperatures.  The method allows for high efficiency purification.  It is very reliable and requires no complex adjustments.  The main drawback is the relatively low rate of water removal.

The above methods may also be used for removal of gases, solids and acids from transformer insulating oil,  e.g. thermovacuum purification is also a good method for removing unwanted gasses.  Centrifugal purification can also remove solid particles.  Single and multiple use filters with a high degree of purification are also used for the same purpose. Such filters must be replaced from time to time.  Acidity of the oil is decreased by the adsorption method and has become a highly desirable process for a more complete maintenance service for your electric power transformers.

The most modern and cost effective method for performing transformer maintenance is the industry leading GlobeCore Process which uses a Fuller’s Earth sorbent filtering system.  The GlobeCore Process uses the adsorption method to not only purify the transformer insulating oil, but to completely “regenerate” the oil by removing the contaminates and moisture from the entire transformer and not just the oil.

Unlike the older adsorption methods, the GlobeCore Process has eliminated the need to dispose of spent sorbent materials through the development and use of an automatic sorbent reactivation system.  This technological breakthrough has now made the GlobeCore Process of transforemer oil purification and regeneration the most efficient and cost effective transformer maintenance system in the world.

It’s time to get with the Process.  The GlobeCore Process!

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