Alumina Raschig Ring
it is a Alumina Raschig Ring shaped bed grading media for filtration of contaminants, pressure drop relief and distribution optimization purpose, the grading rings are layered on the top of the hydrotreator and hydrocrackers:

To remove impurities from feedstock and to further optimize flow distribution
To provide more fouling resistance than other types of top bed catalysts
To reduce the rate of bed fouling caused by coke deposition and
To reduce the amount of polymerization reactions in olefinic feeds
To minimize pressure drop
High void space.

Alumina Raschig Ring provides high tortuous pathways, which trap foulants and particulates from feedstock as it passes through the material.

Alumina Raschig Ring is a cost-effective material with high particulate capacity for pressure drop control.