Silica gels are the most commonly used desiccants and consist of 99% silicon dioxide (SiO2). For the ventilation of hydraulic units, gearboxes, storage tanks, transformers, etc., the silica gel orange-green is the most suitable desiccant due to its high water absorption capacity of up to approx. 40% of the dry mass, easy regeneration in the oven, harmless handling and good high-contrast color indicator.
With a granule size of 2-5 mm spheres, the pressure build-up is very low as well as the gap volume is optimal to ensure a very good contact of the water molecules to the silica gel surface. Thus, with a properly designed adsorber, dew points as low as -40°C can be achieved.
The regeneration temperature of silica gel orange-green is 120°C.
Depending on the selection of the color indicator in the silica gel, the drying efficiency and the maintenance interval of an adsorber can be influenced. A selection can be made from very strong drying and a short maintenance interval to weaker air drying and a long maintenance interval.
Other silica gels