Compressed air systems are a reliable option that provide steady, continuous flow of air and non-heat generating power that is essential for many large manufacturing and industrial applications for an improved production output. In fact, so important are compressed air systems in these demanding major industrial and manufacturing applications that they are often thought of as having a value equivalent to water, electricity and gas.
But what would happen if the compressed air, so vital to the production process, gets contaminated?
What are the sources of compressed air contamination?
To find out a solution to compressed air contamination, it is necessary to identify the source of its contamination. The 4 main sources where compressed air may get contaminated are:
· The ambient air that the air compressor sucks in
· The air compressor itself
· The air receiver in the system
· And finally the distribution piping
Pollution in any of the above 4 sources will mean contamination in compressed air used for the manufacturing applications. As compressed air is a crucial factor in the production process, it is extremely important that the compressed air is of the right quality. If contaminated air comes into contact with the final output it could have a detrimental effect on the production, hinder quality, escalate rejection costs and have a negative impact on your customers and finally the business.
Ten Contaminants that affect the compressed air system:
Water vapour, Water aerosol & Condensed water
Ambient air always contains moisture in the form of water vapour. Generally 99.9 % of the liquid contamination in a compressed air system is water. When ambient air is compressed, the air temperature rises, causing an increase in water vapor retention. If water vapour is included in compressed air systems it can cause problems such as increased leakage, pipe corrosion, reduced tool performance, high maintenance costs, disturbances in control systems and instruments etc.
Oil vapour in compressed air
As with water vapour, ambient air also contains oil in the form of hydrocarbons which may be sucked into the air compressor. As with water, oil vapour also condenses within the system when cooled and will only add to the contamination in compressed air.
Liquid oil & Oil aerosol
Many air compressors use oil for lubrication, sealing as well as cooling during the process. In fact, in lubricated compressors oil is a part of the compression process and is included in the compressed air either fully or partially as liquid oil or oil aerosols.
All the above air contaminants, (water vapour, water aerosol, condensed water, oil vapour, liquid oil and oil aerosol) when combined, form an acidic condensate that can damage the storage and distribution of the compressed air system. These air contaminants can also negatively affect the plant equipment and products that come in contact with contaminated air.
Dirt in the atmosphere
A manufacturing facility contains millions of dirt particles that are too small (less than 2 microns in size) to be caught by a compressed air filter (line filter used to remove contaminants from compressed air after compression has taken place) and thus pass directly into the compressor itself. These dirt particles can cause blockages in the system and affect final production quality.
Bacteria and viruses
Atmospheric air contains millions of micro-organisms such as bacteria and viruses which, if they get into the sterile production environment, can adversely impact product quality and impact production costs negatively.
Compressed air systems which do not have enough purification filters in place and were operated with wet piping before purification can encounter rust and pipe scales in their air receivers. These pollutants can damage the equipment and also cause blockages that may adversely affect final output.