Tag Archives: oil purification

Reincarnation of the hydraulic oil lifecycle

Tierra Fuller, , ,

The lifecycle of hydraulic oil depends on several parameters which can extend or shorten the cycle. Some of these are viscosity, acidity and the amount of additives. Contaminating particles, free water, unfavorable operating conditions (temperature, loads and other conditions) all contribute to aging of oil.

Oxidation is further accelerated at temperatures exceeding 60C or in contact with some other materials. Presence of solid particles, especially larger than 2 micron, promote oxidation.

Contaminants are present in all hydraulic equipment. When the units are operated, friction causes additional solid particles and dust to enter the oil.

Therefore, to maintain high quality of oil and is operational parametes, it is important to protect its chemical composition, avoid overheating and protect the oil from water, minimize the amount of solid particles in the oil.

Oil filtration schedule is important to any industrial business. Filter efficiency depends on pore size. Large solid particles are retained by the filter as the oil passes through it, the smaller ones pass through the filter. Most modern filters successfully remove 1 – 5 micron particles.

Relative amount of solids increases as the size of the particles decreases. This means the oil will still be contaminated after filtration. The amount of contaminating particles will increase during operation and oxidation will be accelerated further.

Using the experience of many companies, it can be inferred that the dominating reason for malfunctions of hydraulic systems is related to contamination of the oil by solid particulate matter. Therefore it is extremely important to remove such contaminants.

As mentioned above, filtration alone is not enough. Microscopic particles pass through fine filters. Besides, water and air need other removal methods.

This is specifically what the UVR systems were designed for. Mobile or stationary design, direct connection to hydraulic systems for oil processing are just some of the features of this regeneration system.

Several filters, special pumps, heating and absorption allow removal of the smallest particles, as well as water and air from hydraulic oil. The sorbent media is can be reactivated shortly after running purification cycle is complete.

Oil purity regulations, savings on new resources and storage, unification of purification and filtration equipment are just some of the benefits of using the UVR type hydraulic oil purification system.

Tests and Trials: Sport, Art or Industry? Analysis of Transformer Oil Purification

Tierra Fuller, , , , , , ,

The correct use of oil guarantees the reliability of industrial equipment and the prevention of equipment failures.  Transformer oil is a dielectric insulator and a coolant.  It also serves as an arc extinguisher preventing shorts and internal fires.

Transformer oil parameters degrade over time as the oil ages.  Oil oxidation is mostly caused by external elements such as water, air, acids and heat.  Aging of oil is best indicated by its acidity level, water content, and sediment and sludge formation.

Sludge accumulates in the solid insulation, the core, in cooling channels and other places inside the transformer.  Sludge is a dangerous enemy that degrades the oil’s cooling and heat transfer capabilities and damages the solid insulation causing it to disintegrate.  A short-circuit in the transformer windings becomes a much higher possibility due to oil degradation and sludge build up.

The acid level of the oil, as measured by the “Acid Number“ is the main indication of oil degradation and oil aging.  Acidity is measured by special litmus paper that changes color when subjected to contaminants.  Acids can damage cellulose insulation and metal parts of the transformer.  Acid levels can also measured through an oil analysis program.

The Acid number, as the main indication of transformer oil quality, is the amount of grams of KOH required to neutralize all free acids in one gram of oil.  The Acid number indicates how much the oil has aged and whether it should be regenerated using the GlobeCore Process.  Once the Acid number reaches 0.08 and higher, the transformer oil becomes aggressive and begins to destroy the solid insulation of the transformer.  The Acid number therefore, is the best indicator of when to service your transformer before irreversible damage is done to the insulating paper.

Besides chemical parameters, transformer oil must comply with certain physical and electric parameters.  Degradation of these important oil qualities may indicate problems inside your power equipment.

For instance, the oil’s flashpoint must be high enough to ensure fire safety in overload conditions and high temperature increases inside the transformer.

Dielectric strength of transformer oil is important for the prevention of breakthroughs in the transformer insulation.  This parameter is measured regularly by high voltage breakthrough indicators.  Transformer oil is tested six times with 10 minute intervals between each test.  The average of six tests is used to determine the dielectric strength.  If the results are unsatisfactory, another sample is tested and a decision on the course of action is made.

Fresh or used transformer oil must be tested before being placed into the transformer.  Some parameters tested are particulate matter content, general oxidation stability, transparency, dissipation factor, flash and setting points, viscosity, acidity and water content.

These measures are designed to identify and resolve problems before the they can cause a transformer failure shutting down the transformer.

Transformer oil is purified of contaminants, acids and gases in purification and regeneration equipment specifically designed for transformer maintenance.  Complete preventive maintenance systems, such as the GlobeCore CMM-R line of equipment will reduce costs and downtime while increasing operating profits.

Why do we use dry and clean transformer oil? Importance of transformer oil purification.

Tierra Fuller, , ,

Reliable operation of transformers is dependent on the condition of internal insulation. Transformers are insulated by liquid (oil) and solid (cellulose) insulation. Dielectric oil accounts for about 80% of the system’s dielectric strength. It is a very good dielectric, and it permeates cellulose insulation further increasing the dielectric strength of winding insulation material. Viscosity characterizes the oil’s cooling ability.

The oil must be protected from oxidation, avoiding overheating and contact with contaminants, since most of transformer failures are due to insulation failures.

Cellulose materials are the weak link of transformer insulation. Contamination of internal insulation by things like water, dissolved gas and solid particles cause degradation of insulation materials. Cellulose insulation quickly accumulates contaminants.

One of the main factors of transformer oil and solid insulation degradation is water. It inevitably enters insulation systems. The result of its influence (along with other contaminants) is aging of oil and formation of various degradation products, sludge, acids etc.

oil

When oil absorbs air and moisture, the aging process occurs even under light loads. Water in transformer oil consists of free water, water solved in oil degradation products and chemically bound water. It is impossible to extract all water from solid insulation.

Transformer oil can accept more water at elevated temperatures. When oil is again cooled, this water precipitates form the oil and enters solid insulation. Cellulose insulation absorbs water form the oil and retains it. Acids resulting from oil aging have a negative effect on cellulose and metals and form soapy metal, aldehyde, alcohol etc which form acidic sediment on solid insulation, internal surfaces of the transformer, breathing system, cooling system etc.

While water and heat are damaging to solid insulation, correct maintenance of cooling and insulation system can extend their lifetime to 60 years. Equipment formerly used for transformer oil drying only is quite obsolete. At present oil can be restored entirely. The parameters of regenerated (reclaimed) oil are extremely close to those of new oil. Service life of well maintained transformer oil is virtually unlimited.

The modern comprehensive transformer oil purification plants include degassing, drying and lightening, as well as filtration and regeneration. The resulting regenerated product is as good as new. Therefore, new oil purchase costs are reduced. The cost of purchased and regenerated oil is recovered.

The cost of regeneration of used transformer oil is always considered in relation to the high cost of purchasing new resource and possible downtime costs. It is quite obvious that owners of complete transformer oil regeneration plants are always in advantage.