Compressed air filter selection for different industries

Air compressors are used in different industries and filter selection can vary

Compressed air is not inherently clean, just like the environment around it. The air in a compressor system is full of all kinds of particles, aerosols and vapors that can contaminate the final process and product, and cause harm to machines and other equipment.

That's why it's important to choose an air filter! In addition to choosing the right air compressor, the aftertreatment system is also quite critical to improve the quality of compressed air with a powerful filtration system, while increasing the efficiency of the system. The number and type of filters required for an air compressor will depend on the application of the compressor or the air quality required for the process.

Types of compressed air filters

What is a compressed air filter?

A compressed air filter is a piece of auxiliary compressed air equipment that helps remove any unwanted and potentially harmful contaminants from the compressed air; as mentioned above, these can be aerosols, particulates or vapors. Particles are tiny solid particles such as dust, dirt, metal particles from pipe corrosion and pollen. Aerosols are small liquid droplets (i.e. oil and/or water, depending on the type of compressor), while vapors are liquids that have been converted to gases.

There are four types of compressed air filters: coalescing filters, vapor removal filters, dry particulate filters, and catalytic oxidation oil removal filters. Although each type ultimately produces the same result (removal of contaminants), the four types work in different ways.

Coalescing filters

Coalescing filters remove water, oil and aerosols from the air while preventing contaminants from re-entering the air. These filters also remove particles from the compressed air, trapping them in the filter media, but can cause pressure drops if not replaced regularly. Coalescing filters do a good job of removing most contaminants, reducing particle concentrations to 0.1 microns and liquid concentrations to 0.01 ppm.

Vapor Removal Filters

Vapor removal filters work on the principle of adsorption. They typically use activated carbon particles, carbon cloth or paper to remove lubricant aerosols Vapor removal filters work well after coalescing filters because they capture and remove the gaseous lubricant that will pass through the coalescing filter.

Drying Particle Filters

Dry particulate filters are typically used to remove desiccant particles after an adsorption dryer. Dry particulate filters work in the same manner as coalescing filters.

Catalytic oxidation oil removal filter

Catalytic oxidation oil removal filter is used to remove oil contamination impurities in compressed air by the catalytic effect of the catalyst, usually a special filter for oil contamination in compressed air, so that the removal of oil contamination can reach 0 level of oil-free state, is currently more mature oil removal technology.

Understand the type of air compressor filter, then what filter is suitable for the existing compressor? Do I need to replace the existing filter?

What filter is right for my air compressor?

Not all compressed air applications are the same! Different applications require different levels of filtration, so in order to choose the right type of filter for your compressor, you need to understand the specific application area of your air compressor. For example, compressed air used in a pharmaceutical power process will require higher quality compressed air than that used to power pneumatic tools or fill tires.

Also, consider how important energy efficiency is to your equipment! Lower energy consumption leads to lower electricity bills. High efficiency filters can produce very clean air (e.g. removing particles smaller than 0.01 microns) while minimizing pressure drop.

Determining when the filter needs to be changed depends on the operating hours of the air compressor and the quality of compressed air required:

A drop in pressure may also indicate the need to replace the filter. When considering whether to replace a compressed air filter, consider the following questions.

>Is the equipment life expired?

>Does the air audit show air quality below acceptable limits?

>Is the pressure drop exceeding acceptable levels?

>Does the pressure drop exceed the manufacturer's change point?

If one of the above questions is met, it means that a new filter is needed (Note: catalytic oxidation type of oil removal filter above the problem, catalytic oxidation type of oil removal equipment is applied catalyst as the core material, the catalyst only plays a catalytic role, does not produce consumables, no need to replace the cartridge and other consumables. Therefore in the oil removal this one is quite simple), many people also consider replacing the filter cartridge before the proposed pressure drop or air quality problem occurs, because the increased energy cost of reducing air pressure may be higher than the increased energy cost of replacing a new filter.

Lingyu Machinery - moisture removal coalescing compressed air filter