Silica gel blue is a semi-transparent glassy substance. It contains Cobalt Chloride, which is a heavy metal salt and works as an indicator. Silica gel blue is available in beads or granules form and is of light pinkcolor when fully absorbs moisture while as silica gel orange beads are also use for effective moisture drying in breather transformer applications when it free from moisture then its color change to dark green. When it comes in contact of moisture its color gradually changes from dark blue to light blue and then finally pink and hence indicates the absorption of moisture. This change in color of silica gel blue indicates and alerts the user that it needs to be replaced or regenerate. It is basically used in the breathing process of Transformer. Breathing is a phenomenon in which transformer Breathe-In or Breathe- out the air from its body due to thermal tightening & extension of oil mass. This air contains moisture and hence the proper working of the transformer can get affected because this humidity can change the dielectric strength of the oil. So use of silica gel blue comes in handy for proper functioning of the transformer.
Change of color and the related indication
- Blue Beads & Crystals – partly humid. (Absorbed water for about 15% of its weight)
- Orange Beads – saturated with moisture (Absorbed water for about 30 – 40% of its weight)
Silica Gel crystals can be regenerated by heating it inside a ventilated oven at to 150 0C, until the color becomes deep blue again and hence it becomes moisture free and ready to use again.
There are various Characteristics of silica gel breather and some of them include its working as a perfect dehumidifier.It gives required indications about replacement or regeneration.It is Non-Toxic.It is DMF Free.It is a very inertmaterial; it will not corrode other materials. It is non-flammable.
Desiccant packets containing blue indicating silica gel are utilized in compressed air systems. It is used in railway locomotives to reduce mechanical failure because of the presence of moisture. Compressed air systems with moisture absorbers are used in combination with high-frequency satellite and radio transmission systems, to prevent radio signals from weakening. Orange indicating silica gel desiccant can be used as a tool for preserving important documents in libraries and museums as important information can get destroyed due to moisture.