WIN-Mesh® Mist Eliminators

WIN-Mesh® Type Mist Eliminators consist of a pad of knitted wire mesh usually sandwiched between grids for mechanical support. Except for units less than about 600mm diameter, they are normally split into sections of between 300 to 400 mm wide to facilitate installation through a vessel man way.

The pads are cut slightly oversize to ensure a snug fit and thus eliminate any possible vapor by-pass either between sections or between pad and vesselwall. Each mesh pad is formed from crimped layers of knitted fabric with the direction of the crimp rotated 90 in each adjacent layer to a provide a uniform voidage together with a high ratio of filament surface per unit volume of pad.

Specifications:
WIN-Mesh® Type Mist Eliminators are manufactured in a variety of materials.
HE - High Efficiency removal of fine mists,
GP - General Purpose,
DS - Dirty Service where fouling is an issue,
HC - High Capacity

Mesh pads should be sized so that the face area provides a vapor rate of approximately 80% of the maximum allowable re-entrainment velocity. For estimation purposes, suitable design velocities occur at a K-factor of 0.11 m/s for vertical fow, or 0.15 m/s for horizontal gas flow (due to better drainage):

VS= K.{(ÞL - ÞV)/ÞV }0.5
where Vs = Max vapor velocity (m/s)
ÞV = Vapor density (kg/m3)
ÞL = Liquid density (kg/m3)

Operating pressure loss across the pad within the above design range is normally less than 50 mmH2O depending upon mesh density, pad thickness, liquid loading and vapor rate.

An approximate pressure drop can be estimated with the formula:
Wet ΔP(mmH2 O) = C.(Þ L - ÞV) K2..t
Where C = 16.5 for a typical ’GP-DBA’ style WIN – Mesh Type Mist
Eliminators, and ’t’ is the pad thickness in meters.

For optimum designs the K-factor should be modified to take into account the operating pressure, liquid viscosity, surface tension, liquid entrainment etc.