Zone 1: Inlet distribution zone

The inlet distribution zone provides 2 functions. First the installed internals – such as inlet gas distributors or an open halfpipe – knock out the majority of the incoming liquid. Second the internals distribute the incoming gas flowas uniformly as possible. The function of the inlet distribution zone is often underestimated in its com-plexity and requires special care in its design.

Zone 2: Fine separation zone

In the fineseparation zone all remaining liquid is removed from the gas flow.Technologies used for the separation are inertial impaction and direct interception – covering a particle range starting from 2-3µm. The fineseparators can be equipped with perforated plates – for flowstraightening purposes – ensuring the optimum function of the separator.

Zone 3: Liquid collection and drain zone

In this zone all pre-separated liquid (from zone 1) and from the fineseparator (zone 2) is collected and drained off. The bottom section of the vertical KO drum holds the collected and separated liquid coming from zone 1 and 2. The downcomers (drain pipe typically coming from zone 2) are mounted as close as possible to the vessel shell wall and will not be positioned in close proximity to the inlet gas distributors.The height of zone 3 depends on process parameters such as hold-up time, surge time and the amount of liquid passing through the vessel.