Specification of the silica gel used in Transformer Breather
Specification of the silica gel used in Transformer Breather
(OP)
It there any standards or specs. for the silica gel used in the transformer breather ( ranges 2.5-5 MVA)
such as size (in mm or mesh), shape ( spherical , ... ), water absorption capacity , loss on drying , ...
There are many products/manufacturers of blue indication silica gel. Which one could fit for the transformer application ??
specially that the transformer's manual doesn't mention any data about the silica gel.
Thank You
such as size (in mm or mesh), shape ( spherical , ... ), water absorption capacity , loss on drying , ...
There are many products/manufacturers of blue indication silica gel. Which one could fit for the transformer application ??
specially that the transformer's manual doesn't mention any data about the silica gel.
Thank You






RE: Specification of the silica gel used in Transformer Breather
RE: Specification of the silica gel used in Transformer Breather
I have found that blue indicating silica gel consists of cobalt chloride which is toxic and carcinogenic.
It was thus prohibited in European and American markets since 2000.
The new alternative is the ORANGE silica gel which is indicative and depends on organic substance (Methyl Violet).
Some type changes from orange to colorless , others change from orange to dark green.
RE: Specification of the silica gel used in Transformer Breather
Silcagel is doped with humidity indicator ( 0.5-1% by weight cobalt Chloride) so that deep blue will turn to pink when gel is changed from dry to wet stage. This will signal regeneration (drying at 120 C for 2 hours) of gel so that moisture will not get in to transformer. It is a good practice of transformer maintenance that gel should be dried soon the color change starts and not wait for changing the color completely. In 2000, European Union declared Cobalt chloride as a hazardous material and banned its use. Methyl violet replaced the cobalt chloride as humidity indicator where color change is from orange to green or in some brands to colourless,.Some popular brands are Envirogel TM, Trockenperlen TM, sorbead orange etc.One drawback with these new indicators are that they start changing color at a humidity content of 6% by weight.