Regeneration / reclamation of transformer oil
This is process of water and all oxidation products removal from insulating oil.
Transformer oil regeneration is performed on-site while the oil is in power transformer
(on-load), barrel or any other tank.
Process of regeneration/reclamation includes the following:
» PHYSICAL - CHEMICAL REGENERATION AND DEHYDRATION OF TRANSFORMER INSULATING OIL
Restoration of all physical, chemical and electrical oil characteristics
Guaranteed oil characteristics after regeneration
» tgδ of insulating oil
» Neutralization/Acid number
» Interfacial tension
» Dielectric strength
» Water content in insulating oil
» Particles
Used oils are regenerated to the level of a new-unused ones in accordance with the
specifications for the new oils, IEC 60296 (including oxidation stability).
Operation principle
Oil regeneration is a physical-chemical treatment based on adsorption process, i.e.
oil circulation through the columns with granulated adsorbents. Aging products are
adsorbed and retained on the active surface inside adsorbent pores. This technological
process is based on use of synthetic adsorbents which are more active in comparison
to natural adsorbents such as bleaching clay, infusorial earth, Fuller's earth.
Characteristics of adsorbents (chemical structure, surface area, pore diameter ...)
are adjusted to remove all products of aging, i.e. oxidation products of mineral
oils, primarily transformer oils.
An important adsorbent property is ability to remove peroxide as one of the main
promoters of the oil aging, ie. total insulation aging, what was confirmed by laboratory
tests.
However, the main advantage of synthetic adsorbents is possibility of their reactivation.
After saturation, adsorbents can be reactivated a virtually unlimited number of times
without losing their adsorption capacity. Reactivation is process of adsorbed aging
products removal in ecologically correct manner. By combustion of adsorbed aging
products full oxidation is achieved, while only products of combustion are water
and carbon dioxide.
Examination of harmful and dangerous substances emission was performed by an accredited
company ENVIRONMENT CENTER Ltd. (Serbia). It was confirmed that the level of harmful
and hazardous substances were under limit values. This has proved that there is no
environment pollution at any stage of oil (characterized as a hazardous waste) regeneration
process and that oil remains clean and safe for the environment.
Design of adsorbents and selection of their optimal characteristics was carried out
on the basis of a large number of laboratory tests in referent institutions - Institute
of Physical Chemistry (Belgrade), Faculty of Physical Chemistry (Belgrade), Nikola
Tesla Institute in Belgrade, Oil Refinery Novi Sad, Energy Consult Oslo - Norway,
Vasteras AB Petroleum Kemi - Sweden, National Institute ICMET Craiova Romania.
Oil characteristics tests, before and after treatment, were carried out in Serbia
(Nikola Tesla Institute and Oil Refinery Novi Sad) and abroad (Sweden, Norway, Czech
Republic, Bulgaria, Romania, Russia, Macedonia).
Technological process VIMAP REG2000 ON-LOAD is applied in Serbia, Romania and Montenegro.
All the equipment and granulated absorbents are products of VIMAP d.o.o.
Oil regeneration process main characteristics
» No oil heating
» No oil vacuuming
» New oil not required, thus saving resources
» Cost effective
» Ecology friendly (zero gas emission and no disposal of waste oil)
» Transformer washing not required
» No exposing of transformer core to atmosphere
» No loss of production, can be performed while transformer is energized
» Low energy consumption
» Reactivation of synthetic adsorbents for few hundred times
» Simple machinery construction
» Simple handling
» Easy installation
» Minimum supervision
» Field operation in all weather conditions
» Minimal power consumption (0.5-3 kW)
