Feed diffuser distributes the incoming flow from inlet nozzle of the reactor. In downflow reactors, the inlet nozzle is also used as a hatch for installing the internals and catalyst in the reactor. Feed diffuser can be attached either to this flange or may be sitting in a groove between flanges. Depending on flow dynamics in the reactor top head and technological process, feed diffuser is made of plates, grates and perforated sheet metal. Impingement plate of diffuser faces the incoming flow, which can be diverted through several channels, which sizes depend on incoming pipe diameter and the nozzle height.
In upflow reactors, feed diffuser sits above the inlet nozzle. If requested by a customer, the equipment can be made removable to simplify cleaning.