Scrubber internals refers to a group of devices specifically designed to remove particulates and or gasses from industrial exhaust streams. Scrubber internals work together in achieving maximum removal efficiency of pollutants. Each scrubber internal has a specific function in the scrubbing process. The design of scrubber internals can range from very basic to extremely complex depending on the customer’s requirement and the exact application. Various materials can be used in the construction of internals including a vast variety of plastics and metals. Temperatures, contaminates and cost will typically determine the material of construction. For example, KemFlo can manufacture their plastic random packing product the Tri-Pack in a variety of resins including Polypropylene, CPVC, Kynar, Tefzel, Teflon and more.
Scrubber internals include the following devices or items:
Mist Eliminators are basically metal or plastic wire mesh held together with a grid on either side of the mesh and is used to collect and separate liquid from gases.
Liquid Feed Pipes are used to introduce a liquid into the unit and is typically positioned above a liquid distributor.
The liquid distributor collects liquid from the feed pipe and is specifically designed to evenly distribute the liquid evenly over a packed bed.
The Packed Bed may include a variety of random packing types and or materials such as KemFlo’s Tri-Pack, Pall Ring or Plastic Saddle style. KemFlo manufactures a Tri-Pack and Pall Ring in 1”. 2” amd 3.5” sizes and both styles are available in a variety of resins. The random packing sits on a packing support which purpose is to support the random packing and prevent individual packing pieces from falling into lower levels of the scrubber.
The packing support must be designed in such a way that its openings are small enough to prevent the random packing from falling through but with enough open area as to not prohibit liquid and gas flow
through the system. It must also be designed to hold the weight of the bed of random packing.
In many cases a bed limiter is positioned directly on top of the packed bed and prevents the random packing from being blown into the upper levels of the unit. Like the packing support the bed limiter must be designed so that the random packing can not escape through its openings but also must not hinder liquid and gas flow.
Vapor distributors are typically located near the bottom of the scrubber unit. The purpose of the vapor distributor is to evenly introduce the gas into the lower portion of the scrubber. A vapor distributor is basically a flanged pipe with a series of holes. The spacing and size of the holes in a vapor distributor are specifically designed based on the gas, flow rate and size of the scrubber.
All of the above scrubber internals are available in a variety of materials such as thermoplastics, metals and ceramics. Determining the best material of construction for internals depends on the application, temperature, pressure and contaminate. It is very important to have an engineer evaluate your specific application to determine the best column internals for your application.
For help regarding plastic random packing please contact Kemflo for more information on our Tri-Pack, Pall Ring or plastic Saddles plastic random packing. Information on KemFlo’s Tri-Pack, Pall Ring and Saddle can be found at www.kempac-packing.com.