Metex OPTI-PACK™ knitted wire mesh Structured Tower Packing is designed to overcome many of the shortcomings of other devices. The packing consists of multiple strands of very fine wire, typically 0.00045” diameter, knitted together to form a 2-ply layer of flat mesh. The flat mesh is corrugated, or “crimped” to give it a uniform, 3-dimensional structure of “peaks and valleys.” These peaks and valleys provide a path through which vapor can readily flow, both radially and axially.

The multistrand fine wire generates high surface area (typically 500 ft² to 800 ft² per ft³) and a “capillary effect” on the descending liquids to promote good liquid distribution, residence time and thin-film development.

The resiliency of the fine wire that ensures that the packing will conform to vessel anomalies between the wall and the internals. These gaps often lead lead to vapor bypassing that keeps your unit from realizing its design performance.

These mechanisms work together to promote the intimate liquid-vapor contacting needed to achieve the separation demanded by high-value-added processing. Typically, structured sire mesh tower packing exhibits Height per Equivalent Theoretical Plate (HETP) in the range of 3 to 12 inches, depending on the application of fluids. In general, these packings offer the highest efficiency per foot of bed and the lowest pressure drop per theoretical stage, versus other mass transfer devices.

Where They Are Needed
Distillation, Stripping and Absorption are often used in chemical processing to recover and purify valuable liquid products. In many circumstances the value of the product and, in fact, the acceptability of the product, depends on meeting stringent purity specifications.

Conventional mass transfer devices such as sieve trays, valve trays, grid packings and dumped packings are often not efficient enough to accomplish the required separation in a reasonably sized new column or in a retrofitted existing column.

Additionally, if the column must operate over a wide range of flows with very high turndown possible, conventional mass transfer device efficiencies may be further reduced. This could constrain the capacity and performance of the unit.