The most widely applicable type of mist eliminator is made of metal or plastic wire with typical diameter of 0.006 to 0.011 inch, loosely knitted in a form resembling a cylindrical net. This tube is flattened to form a two-layer strip typically 12 inches wide, which is then crimped in a diagonal pattern with ridges as shown in Figure 1.
When these strips are laid together, the ridges slant in alternate directions,forming an open structure through which gas flows freely. Such mesh can efficiently capture mist droplets as small as 5 microns (micrometers).For eliminating droplets down to 1 micron in diameter,multi-filament yarns of various plastics or glass are knitted into the mesh. The result is called a composite or co-knit mesh (Figure 2).
In the most familiar application of knitted mesh, the crimped strips are stacked to form a pad with typical thickness of four or six inches. (See Figure 3.) Rigidity is provided by a frame - usually metal - consisting of a grid on each side and rods passing through the mesh. Pads larger than about three feet across are fabricated in sections narrow enough to pass through a manway for assembly inside a vessel.
Mesh pads can be made in almost any shape, but most are round (Figure 3) or rectangular.