Mist Elimination

Mist eliminators remove extremely fine liquid droplets from industrial gases to improve efficiencies of distillation columns and scrubbers. Also, to protect ducts and exhaust fans from corrosion and prevent product loss. Air, generally laden with mist particles, passes though the separation medium.

The droplets are intercepted and collected on the surface of the medium and form larger droplets, which continue to build on themselves and grow to form a liquid “coalesced” stream on or within the separator, which then falls with gravity and is carried away.

There are three principle configurations or styles of mist eliminators. Chevron metal panels are used for particles larger than 12-15 microns. Droplets impinge on vane-like surfaces eventually forming a liquid stream, which gravity feeds into a sump. Wire mesh pads, usually of a knitted wire mesh nature, have a large surface area and can be used when droplets are as fine as 2-3 microns in diameter. The knitted pads are often constructed of a 0.006” or 0.011’ diameter stainless steel wire and sometimes a combination of wire and multifilament synthetic yarns, with metal structural support members to maintain the pads shape.

Both the Chevron and the pad configurations are closely related in operational performance when separations of high-mass, high-velocity, droplet laden streams are required. Low mass, low velocity streams, are used when droplets are smaller than 3 micron. They are captured within a densely packed fiber mat configured in either a deep-bed or candle style shaped element. This capture is largely based on Brownian diffusion.

Mist eliminators typically protect turbines and compressors, aid in salt reductions, remove sulfuric acid, reduce oil concentrations from factory compressed air-lines, asphalt and plasticizer operations and are critical to environmental compliance in many other industrial operations.

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