When working with compressed air, air treatment is crucial to get the result you need. But what line filters do you need? And how do they all work? Find out everything you need to know here.
A compressed air filter or air line filter is used to filter impurities from atmospheric air, like dust, oil and moisture, to make compressed air viable for use.
Just like air dryers, they are a crucial part of the air treatment process to make sure your compressed air is clean and safe to use, and to increase your equipment’s life span.
The working principle of compressed air filters changes depending on the type of air filter you use.
The most common air line filters and their basic working principles:
Particulate air line filters remove dust and other harmful particles from compressed air. Like the membrane air dryer, the particulate filter uses a membrane that only lets air pass through and blocks other contaminants like dust, pollen and dirt.
Particulate air filters are often used after an adsorption dryer like a desiccant dryer. They also filter internal particulate matter like corrosion to help your air compressor live longer.
Benefits of a particulate filter
If you’re looking for a finer filter that removes fumes and vapours, the activated carbon filter is what you need, for moisture you are better off with a coalescent filter.
Activated carbon filters are often referred to as vapour removal filters, perfectly describing how carbon is used to attract gaseous contaminants and immobilise them. The carbon has a large surface area making it a durable type of filter.
As the filter becomes more saturated, however, the pressure will need to drop to reach the same quality of filtration. In order to maintain a reasonable amount of pressure, the carbon filter needs to be replaced every so often.
Activated carbon filters or vapour filters are mostly used for food processing and the production of breathable air.
Reasons to go for a vapour removal filte
Vapour filters are often followed by a particulate filter to catch possible carbon particles that break off into the air.
If you’re looking for a filter to take care of moisture, you are more likely to find what you need in a coalescing filter.
Coalescing air filters remove liquids like water, aerosols, lubricants and other oil particles from the air. They coalesce aerosols into droplets through pressure drops and the tortuous path working principle.
Because of this versatile way of working, coalescing air filters also catch particulates. They are caught along with the aerosol particles, drained and run through an oil-water separator to avoid pollution.
As with the carbon air filters, coalescing filters need regular replacing to avoid the pressure dropping too dramatically.
Coalescing air filters are incredibly versatile, though not very energy efficient.
Choosing the right compressed air filter is an important step when optimising your air treatment system. With these tips, you’re on your way to choosing the perfect compressed air filter.