A: Dwayne Sanders, Sly, says:
A wet scrubber, also referred to as a wet dust collector, is a unique type of air quality control equipment that’s used in several different industrial applications. Different than your typical baghouse or dry dust collector, wet scrubbers use a scrubbing liquid to remove pollutants from your airstream instead of a filter bag or cartridge. Through the impingement process, a wet scrubber can remove harmful gases, vapors, dust, and other pollutants. More importantly, it allows you to remove both particulate and gases or vapors simultaneously from an airstream without needing any additional equipment.
Wet scrubbers can achieve extremely high collection efficiencies of more than 99 percent. The collection process behind wet scrubbers makes them a solution for many industries, including pharmaceuticals, food manufacturing, plastics, and machining. No matter the industry or application, the top three reasons to use a wet scrubber are if you have wet or sticky particulate, humid air, or combustible dust.
If you’re using a standard baghouse, a wet or sticky particulate can clog up your system, impeding its performance. However, by using a scrubbing fluid, a wet or sticky particulate isn’t an issue for wet scrubbers. A quality wet scrubber will be able to handle these types of particulate without the need for any additional maintenance or the risk of premature failure.
While humidity is often associated with wet particulate, issues with humidity can occur independently from stereotypically wet systems. Sand drying applications and certain dry cooking methods are prime examples. In these cases, even though you’re dealing primarily with dry particulate, humid air in the environment can cause condensation to form. When that condensation gets into your baghouse, you’re going to have the same moisture problems mentioned previously. With a wet scrubber, condensation and the resulting moisture isn’t a problem since scrubbing mechanisms are inherently wet.
The third, and often most talked about, reason to use a wet scrubber is to handle combustible dust. Combustible dust and the potential for dust explosions are major safety concerns for any process with ignitable pollutants. Anything from agricultural products like powdered milk and grain flours to metallic and chemical dusts can be combustible. Dispersing these dusts in the confined quarters of a baghouse can make that process area extremely explosion-prone when in the presence of an ignition source and free oxygen. While there are many ways to help minimize the chance for a dust explosion when using a baghouse, making them still a viable option, wet scrubbers mitigate and remove many factors required for an explosion since they use a scrubbing fluid. With a scrubbing fluid, you can remove certain ignition sources like friction, prevent oxygen from directly coming into contact with any dust, and eliminate the dust dispersion needed for an explosion.
Sly, Strongsville, OH, manufactures and supplies air pollution control systems, including dust collectors, scrubbers, and related equipment.