Activated alumina is an aluminum oxide bead with an extremely porous structure and high surface area-to-mass ratio. Activated alumina has a wide variety of applications, including compressed air and gas drying.
In compressed air and gas drying applications, activated alumina will achieve dew points -40°F to -100°F, depending on the dryer design.
In compressed air desiccant dryers, a 1/8" (2-5 mm) activated alumina bead is most commonly used. The 1/4" (5-10 mm) activated alumina bead is typically used as a pre-bed for supporting large desiccant beds or as a buffer for silica gel beds. The 3/16" (5-10 mm) bead is used when pressure drop and surface area requirements fall between the 1/8" and 1/4" material.