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Transformer Oil Dehydration and Degassing

Dissolved gases and moisture in transformer oil (mineral oil) can cause arcing, corona discharges, and overheating, thereby reducing the electrical efficiency and lifetime of the transformer. Water contamination at levels as low as 30 ppm can adversely affect the insulating strength of the oil. Removing water (dehydrating or dewatering) and dissolved gases (degassing) from any compatible liquid, including transformer oil is simple and straightforward with PermSelect® membrane modules and contactors. Moreover degassing transformer oil can be accomplished in batch or continuous mode. Since water vapor and other gases are highly permeable through silicone, these gases can be easily extracted from transformer oil by simply flowing the transformer oil on one side of the membrane, and applying a vacuum to the other side.

How can I dehydrate transformer oil using a PermSelect® membrane module?

NOTE: Certain transformer oils swell the silicone membrane excessively which render the membrane not suitable for degassing. Please contact us to request a membrane swatch to determine compatibility with your transformer oil.

The diagram below illustrates how to dehydrate and remove dissolved gases, including moisture from any compatible liquid, including transformer oil using a PermSelect® membrane module. Pre-filtered transformer oil is supplied to one side on the silicone membrane through the feed port of the membrane module. Vacuum provided from a vacuum pump is applied to the opposite side of the membrane through the permeate ports of the contactor. The highly permeable gases and vapors such as water will permeate across the membrane from the oil to the vacuum side of the membrane, thereby dehydrating the transformer oil by stripping water and other dissolved gases from the oil. This dehydration process can be accomplished continuously or as a batch.



Transformer Oil DehydrationTransformer oil dehydration using a PermSelect® silicone membrane module

MedArray provides its PermSelect® membrane modules for degassing directly to researchers, and to industry through original equipment manufacturers (OEM’s) who are interested in integrating degassing and dehydration solutions in their equipment. We can also customize membrane modules to your specific application. Contact us to discuss your custom application.