Articles & FAQs

Silica gel was patented by chemistry professor Walter A. Patrick, USA in 1919 for use in the adsorption of vapors and gases in gas mask canisters during World War I. During World War II, it was commonly used as a dehydrating agent to protect military and pharmaceutical supplies, among a number of other applications. IIn 1959, silica gel was first recommended for use in museum applications as a buffering agent to control relative humidity (RH) in closed packages.
Silica gel is a highly porous substance that can absorb utpo 40% of its own weight, that is why it is the highest capacity adsorbent available today. Comprised of internal network of interconnecting microscopic pores, silica gel attracts and holds moisture by adsorption and capillary condensation. Water molecules are adsorbed or desorbed by these micro-capillaries until vapor pressure equilibrium is achieved with the relative humidity of the surrounding air.Silica gel is inert, non-toxic, non-flammable and safe to use to protect foods, medicines, sensitive materials and much more.
Most of the power generation companies use silica gel breathers fitted to the conservator of oil filled transformers. The purpose of these silica gel breathers is to absorb the moisture in the air sucked in by the transformer during the breathing process.
When load on transformer increases or when the transformer under full load, the insulating oil of the transformer gets heated up, expands and gets expel out in to the conservator tank present at the top of the power transformer and subsequently pushes the dry air out of the conservator tank through the silica gel breather. This process is called breathing out of the transformer. When the oil cools down, air from the atmosphere is drawn in to the transformer. This is called breathing in of the transformer.
During the breathing process, the incoming air may consist of moisture and dirt which should be removed in order to prevent any damage. Hence the air is made to pass through the silica gel breather, which will absorb the moisture in the air and ensures that only dry air enters in to the transformer. Silica gel in the breather will be blue when installed and they turn to pink colour when they absorb moisture which indicates the crystals should be replaced. These breathers also have an oil cup fitted with, so that the dust particles get settled in the cup. Silica gel breather Thus Silica gel breathers provide an economic and efficient means of controlling the level of moisture entering the conservator tank during the breathing process.