Coalescing filters: Cleaning up air for demanding applications

Air is not clean – neither the one we breathe nor the compressed air we need for different industrial applications. The latter contains particulates as well as aerosols, and in the case of compressed air from oil injected technology then also oil vapours. These contaminants are often microscopically small but can have a damaging – and costly – impact on the sensitive equipment that uses compressed air.

Particulates, for example, are tiny pieces of solid materials, e.g. dust, dirt or small pieces of metal caused by pipe corrosion, that can damage the end product. Aerosols are small droplets of liquid in compressed air that are created from the lubricant, such as oil, and can harm products and people if not properly removed. Vapours / fumes consist of any liquids in the compressed air system, like the lubricant, that have been converted to gas.

However, there are applications for which these contaminants do not matter a lot. For example, use of compressed air to inflate a tire. Let us get to know some of the contaminants we’re dealing with.

Dirt, water and oil are no match for Atlas Copco’s filters. They are designed to remove one or more of the following contaminants:

DIRT: dust, solid particles, rust particles, micro-organisms

WATER: condensed liquid water, water aerosols, acidic condensates

OIL: liquid oil, oil aerosol, hydrocarbon vapor

For all these reasons, the use of filters makes sense for countless applications in a wide range of industries. However, there are also many cases where compressed air must meet certain quality standards, for example in the food and beverage industry or in pharmaceutical applications. Coalescing filters play an essential role in reducing the number of air pollutants to a safe level. But what is a safe level for your application? ISO 8573-1 (ed 2010) has the answer. It is the most important internationally recognized air quality standard and defines the level of pollution that compressed air can contain at a specific point in the compressed air system after it has been treated.

If you are unsure, and only know that you have to protect your system from dust, then you need to find out your air quality requirements. For some applications, such as inflating tires, some contaminants in the compressed air do not pose any problems. Others, such as applications in cleanroom environments, require the highest air purity. Knowing your air quality requirements and which standards to comply with will help you select the right air filter, which could lower your investment costs and ensure that you get the most out of your compressed air system. 

If high-quality, pure compressed air is required, then you need a filter (or filters) to eliminate particles, aerosols and vapors. Otherwise, they can pollute the products they come in touch with, or harm your sensitive equipment. Filters serve as a vital, and in some cases the sole line of defence against many sorts of pollutants, ensuring air quality standards can be met and protecting compressed air filters, downstream equipment, and end products.

To protect yourself from contaminants in compressed air, you must invest in air treatment equipment, such as filters. This is nothing compared to the costs you may incur if micro-organisms or traces of oil enter your end products, especially in the F&B industry or the pharmaceutical industry, which are subject to strict air quality standards.

DD+ pre filter / PD+ (post filter) and UD+ oil-coalescing filters use the wrapped technology that is especially effective for wet particles. The wrapped filtration media offers durability in wet and oil-contaminated environments. The patented Nautilus technology of the coalescing filter series combines multiple wrapped layers to ensure constant air quality in the harshest conditions.