What are the Different Types of Contaminates Found in Compressed Air Systems?

April 30, 2019

Compressed air is vital in the operation of many facilities and industries. From textiles, to food manufacturing, to beer brewing, compressed air is used to manufacture, operate and create millions of products around the globe. Although compressed air is essential to many, it can contain lots of contaminates that need to be removed or filtered before reaching other equipment or final produced products. But what are those contaminates and what can you do to remove them?

Types of Contaminates

Because there are contaminates in the air, naturally any air that comes out of an air compressor will also contain those contaminates, in addition to any contaminates that enter the air stream during compression. These contaminates can be grouped into 5 categories:

  1. Moisture (liquid and vapor)
  2. Particles (dust, dirt, soot)
  3. Oil (liquid and vapor)
  4. Pollutants that affect smell and taste
  5. Viruses/bacteria

Contaminates in the Air Stream

Oil in particular is a contaminate that can be introduced into the air system through two methods: via the oil from inside of the compressor or from contaminated air at the inlet of the compressor. If you are using a piston or oil-injected rotary screw compressor, liquid or aerosol oil that is used to lubricate the compressor can enter your air stream. Also, if there is contaminated air being pulled into the compressor in the form of hydrocarbons, this will also enter your air stream. To remove these oil contaminates, coalescing filters can be used to remove the liquid and aerosol oils. Adsorbing filters can also be used to remove the oil vapor or hydrocarbons before they reach any equipment or products downstream of the compressor.

As the most potentially dangerous of all contaminates, viruses or bacteria can also easily be found in the air stream coming from your compressor. Similar to oil vapor, these viruses and bacteria particles can enter your compressor via the intake and then pushed out through your compressor hoses. To rid your air of these contaminates, a combination of high-efficiency (HE) filters is recommended.

Perhaps the most common contaminate and the one responsible of rusting, molding and ruining equipment downstream of your compressor is water or water vapor. As the atmospheric air is compressed, water molecules become more concentrated. Heat of compression inside your unit raises the temperature of the air dramatically, allowing the air stream to carry a large amount of water vapor. After compression is finished, the air begins to cool and causes condensation to form in the piping. To rid your air stream of condensation and moisture, either a refrigerated or desiccant dryer can be used. Depending on the ambient temperature and the level of "dry" that your air needs to be, a refrigerated dryer is often used in smaller applications with relative average ambient temperatures. Desiccant dryers are often used in larger applications and in very cold climates where condensation and dew can easily form.

Contaminates will always be present in ambient air and in the air stream coming from your compressor, but using dryers and filters can stop these contaminates from reaching tools, actuators, assembly equipment and final products. Pneumatech offers an array of both refrigerated and desiccant dryers along with full filter systems to fit the needs of any application. To browse Pneumatech's product offerings, click HERE.