1. Packed Column Internals

2. Packed Column

3. Factors Favoring Packed Columns
Vacuum systems: Low pressure drop
Small diameter column
Corrosive system
Foaming
Lower liquid hold-up
Batch distillation

4. Objectives of Packing Design
To attain maximum mass transfer and capacity with minimum pressure drop by improving
Aerodynamic properties
Liquid distribution
Gas/liquid contact

5. Properties of Packing High surface area per volume
Hood wettability and good resistance to the pressure (high strength).
Pressure drop should be desirably low. When the size increases, both mass transfer and pressure drop decrease. The optimal size and shape is the one which compromise both factors.

6. Materials Nowadays metal and plastic packing have replaced the ceramic
Ceramic elements are still used when corrosive chemicals are involved and good wettability is required
Metal elements provide good wettability with the advantage of having higher strength
Plastic, usually polypropylene, is largely used because of low cost but they fail in case of high temperature. Besides they have poor wettabiity.

7. Packing Types Random or dumped packing
Structured packing: layers of wire mesh/corrugated sheets
Grids: open lattice structure

8. Random Packing 1st generation 2nd generation 3rd generation
Berl Saddles, Raschig rings
Intalox saddles, Pall rings
Nutter rings, cascade rings

9. Comparison