Sludge Formation In Transformer Oil

Oxidization is the acid that forms in the transformer oil when it reacts to oxygen. This acid will form sludge which will settle on the windings of the transformer reducing the heat dissipation from the transformer. The heat transfer from the windings to the oil is limited thus causing the windings to run hotter. Sludge formation on the windings has a snowball effect on the transformer with more sludge creating more heat, creating more sludge etc. The high acid content together with the excessive temperatures will cause the deterioration of the transformer insulation to be accelerated and if left untreated the transformer will fail.

If there is sludge formed in the transformer oil, it means that the transformer oil has been seriously degraded. Since sludge is a resin-like substance and part of it can conduct electricity, although it can be moderately dissolved in the oil, it will eventually precipitate out of the transformer oil to form a viscous asphaltene. This asphaltene will adhere or deposit on many parts in the transformer, such as insulating materials, the inner edge wall of the transformer shell, radiators, oil circulation channels, etc., which not only accelerates the destruction of solid insulating materials, but also causes insulation shrinkage and loss of the transformer. Ability to absorb impact load, and seriously affect the heat dissipation function, cause local overheating of the coil, increase the temperature rise of the transformer and cause overheating, and the transformer has to reduce the load to run. In severe cases, it may even cause transformer failure.

Therefore, it can be seen that the sludge in the transformer oil is very harmful to the transformer, and the transformer oil needs to be maintained regularly to avoid the generation of sludge. As mentioned earlier, the main cause of sludge in transformer oil is due to the acidic substances which are formed in the transformer oil when the transformer oil reacts with oxygen, thereby forming sludge and continuously depositing. We recommend that you use a single-stage or double-stage high-efficiency vacuum transformer oil treatment equipment developed and manufactured by PureTech for routine maintenance of transformer oil. With this transformer oil treatment equipment, you can run the transformer well without any problem occurs due to the transformer oil sludge and transformer oil failure.

At the same time, for severely degraded transformer oil, we have Transformer Oil Regeneration equipment, which is composed of regeneration treatment with fuller’s earth or silica gel, vacuum dehydration and degassing treatment, and multi-stage precision filtration treatment, which can effectively reduce the acid value and sludge in the oil, and restore the transformer oil performance.