In the modern age, industrial air filters are everywhere. From your home to your car, to your doctor’s office, to the location where your computer’s motherboard chip was made, all of it goes through one form or another of filtration. The purpose is simple, but the methods are anything but. We’ll go through the common applications and the methods used to remove the particulates from the air as well as the benefits of doing so.
Some of the first ever types of filters came from the leftovers of cotton production. With little else to do with the materials they became filters of varying sizes for numerous applications. With the invention of the automobile around the turn of the 20th century, the industrial air filters gained a new market. These filters were used for various applications, from oil to air for the air conditioning unit. This was only the preliminary application however.
Modern inventions have churned out industrial air filters that can remove particulates from the air up to .3 micrometers, which is tiny. A high efficiency particulate air, or HEPA filter, can remove most things from the air that would cause humans problems. Allergens can commonly be removed from the interior air circulation. These HEPA filters are used in other commercial applications as well, such as hospitals where these filters can remove bacteria from the air because it is so good at removing particulates.
The method of removal for these industrial air filters is three pronged. The first is interception, where particles following in a flow of air current run into the fibrous bands of the filter and are held there. Impaction is the second, where larger fibers are going along the flow of air, but because of the way that the filters are made, they are accelerated through the system and come into contact with the threads, burying in the fiber and stopping. Usually the first method is small particulates, and the second is larger particulates. The last method is via diffusion. Diffusion works by a labyrinth mechanism along with existing gases. Since the smaller particles have to work through a maze of closely bound fibers, other gases present, such as air, nitrogen and the like, are bouncing in the maze. As the smallest particulates move through they bounce off these gases erratically which causes them to crash into, and embed themselves into the filter itself. The length of the HEPA filter really becomes apparent in the rationale of forcing diffusion for the smaller particulates. Usually these industrial air filters come in a box and have vertical paneling to force the air to move through it in as close a proximity to the filter as possible to be sure that there is minimal particulate output on the other side.
Industrial air filters are used in highly ‘clean’ environments. Hospitals as well as semiconductor micro processing plants all utilize this form of technology to be sure their product is not tainted. Another method is used to remove particulates in league with large air filters. The air flow is from top to bottom at all times, pushing any existing particulates down into a collection base that meticulously refurbishes the air and pumps it down from the ceiling. Typically this rigorous venting method is reserved for clean room environments, where humans must wear suits in order to enter the area.
These are just a few of the common applications of industrial air filters. From there, we branch off into several different subcategories of filters which work through different mediums, not simply through air. However, the goals are similar; all are meant to purify their product while minimally inhibiting flow.