Vessel Internals – Inlet Devices

Multi-vane inlet devices are used to provide an initial separation of liquid from a gas stream into the vessel and to distribute the gas flow evenly throughout the vessel. Inlet devices also reduce the momentum of the feed stream and dampen any slug or surge flow, providing more predictable vessel performance. Multi-vane devices also smooth out the velocity of gas through the vessel, eliminating local fast moving gas streams and thereby increasing the residence time of this gas in the vessel and allowing greater settling opportunity for entrained liquids.


Multi-vane inlet devices provide a number of advantages to the operation of a gas/liquid separation vessel. The vanes of the device direct the feed against the walls of the vessel. Larger droplets impinge against the sides of the walls where they coalesce with other droplets to drain liquid into the bottom of the vessel from where liquids are periodically drawn off. Immediate removal of the larger droplets from the stream allows downstream vane mist eliminators to collect the smaller droplets more efficiently.


Multi-vaned inlet devices are used in both vertical and horizontal vessels and are typically mounted on a flange on the vessel inlet. By improving separation of liquids, multi-vaned inlet devices may reduce vessel size. They can also be fitted on existing vessels to improve separation performance. To facilitate original manufacture and subsequent maintenance, they are supplied in segmented bolt together sections that can be passed through vessel manways for installation inside the vessel.