Common Terms Associated With Plastic Random Packing

Random Packing: Also referred to as dumped packing.  These are individual pieces of packing of a specific configuration which are randomly packed into a column. Material of construction for random packing may be plastic, metal or ceramic.  

Mass Transfer: The movement of mass from one phase to another.

Scrubbing: Removing a contaminate from a gas stream.

Air Stripping: Removal of a contaminate from a liquid stream.

Injection Molding: The shaping of plastic parts by injecting heated resin into a mold.

Packing Configuration: Refers to the specific shape and style of plastic random packing such as the Tri-Pack, Pall Ring and Saddle style packing.

HTU: Height of Transfer Unit.  The height of packing which gives a change in composition equivalent to one transfer unit and is a direct measure of column efficiency.  

NTU: Number of Transfer Units.  This is a measure of difficulty of separation.

Geometric Surface Area: Refers to the total physical area packing upon which mass transfer can take place.  Typically measured in (FT2/FT3).  Example the Kempac 2” Tri-Pack has a geometric surface area of 48.  

Wetting:  The wetting qualities of a specific tower packing refers to its ability to provide adequate area for liquid and gas contact.  Material of construction also plays a part in this.  

Liquid Distribution: Refers to a random packing’s ability to evenly distribute liquid through the packed bed section of a column.  

Packing Factor: Established performance evaluation for a specific random packing style and size.

Void Space: Is the actual open area or space of a specific configuration or style of random packing.  Example: The Kempac 2” Pall Ring has a void space of 92%.

Fouling: Build-up of sediment on individual pieces of random packing or in packed beds.

Settling:  Refers to the tendency for some random packing styles to not uniformly sit in a packed bed resulting in a shorter packed bed than originally designed.

Nesting: Refers to void spaces created in packed beds buy some types of pacing due to their design.  The Tri-Pack is specifically designed to avoid this.