The Unique and Uniform arrangement of structured packing offers many advantages over other types of packing and trays. Such types are used in many wide applications where precise liquid spreading is needed. Several types of structured packing that can be used in process plants are as follows,

Gauze/Wire mesh – This type of packing is mostly preferred for deep vacuum and low liquid rate applications. It offers lowest pressure drop per theoretical stage. Its specifications make it ideal choice for processing of specialty chemicals, Pharmaceuticals and for temperature sensitive materials.

Knitted – This type of packing is used in smaller diameter columns by rolling into one-piece layer. It can also be wrapped back and forth to create rectangular bricks to be used in column manways. The multi-strand wires are used in this type which offers high surface area and high mass transfer efficiency at a higher-pressure drop than woven gauze.

Sheet Metal – This type of packing can handle wider range of vapour and liquid rates and process services too. Process applications range varies from low-pressure drop vacuum and atmospheric distillation services to medium high-pressure absorbers. Sheet metal packing can even handle a modest amount of fouling with adequate liquid loading to keep the packing wetted. This special application separates it from other types of packing.

Grid – This type can provide extended operation mostly in fouling services. Grid packing is nothing but the corrugated sheets with stamped blades. Both types are durable with large open areas to facilitate highly fouling process streams. Corrugated grid packing has a smooth surface to minimize fouling. This type of packing is constructed of much thicker material than the normal sheet metal packing.

Structured Packing Versus Trays-

Packing trays are generally used when a column is experiencing a bottleneck issue. These trays are replaced with structured packing for three reasons:
1.They provide extra inter-facial area for contact between vapor and liquid.

2.To process corrosive liquids in a column.

3.Structured packed columns are shorter in height than trayed columns.

4.It offers better separation efficiency.

Structured packing is advantageous in applications that need constant contact, rather than the staged contact provided by trays.