Inline Vane Separator

How it works

The mixture enters the 8″ inlet and strikes the box baffle, which drops bulk liquid out of the stream before it reaches the vanes. The sealed bundle casing closes the vessel across its full bore, so the gas has no path to the outlet except through the vane bundle.

Passing the bundle, the stream is forced to change direction several times. Low-density gas negotiates the path; high-density liquid cannot turn with it. At each turn a centrifugal force throws liquid particles onto the wetted vane wall, where they coalesce, absorb further droplets and convert to sheet flow.

Sheet flow travels into the vane pockets. Once inside, the liquid is isolated from the gas stream and protected from re-entrainment. The pockets discharge to the drain pan and troughs, then fall by gravity to the sump below, where collected liquid pools in the liquid-sealed sump and discharges through the 2″ drain. Clean gas crosses the dry plenum and leaves the 8″ outlet.

Pocket vane against hook-type vane

• Shielded pocket. Collection and drainage are uninterrupted and protected from re-entrainment, so each vane handles a higher liquid volume.

• Lower pressure drop. More capacity than hook-type vanes for the same duty.

• More laminar flow. An advanced flow profile keeps turbulence down through the bundle.

• Smaller bundle. Less vane area for the same application, which means a smaller, more economical vessel.

Separation performance and the inlet coalescer

Efficiency falls as droplet size decreases. To separate below the vane threshold the bundle must be preceded by a coalescer — either a hookless vane bundle in the inlet nozzle, or the stainless wire mesh pad on the vane face shown in the model — which grows incoming droplets to a size the vanes can remove.

The wire mesh pad merges fine mist into droplets large enough for the vanes to catch, which is what carries removal from the plain-bundle threshold down to 3 microns. Without a coalescing stage the bundle works on the droplet population it is given.

Sizing

Vane separators are sized to the duty, not selected from a size list. Vessel diameter, bundle face area and nozzle sizes follow from flow rate, operating pressure, gas and liquid densities and inlet loading. Supply those with the connection schedule and required code stamp; the arrangement shown in the model — AVS-24 with skirt and drain — is a representative build of that arrangement.

Typical service

• Gas transmission and gathering. Liquid knockout in the line ahead of meters, compressors and regulators.

• Compressor protection. Taking entrained liquid out of the suction stream so it does not reach the machine.

• Steam service. Removing condensate carried with the steam ahead of turbines, traps and process users.

• Compressed air. Water and oil carryover removal downstream of aftercoolers and receivers.

• Fine mist duty. Applications that need a coalescing stage ahead of the vanes to bring droplet size up to what the bundle can capture.