The types of contaminants in compressed air and the consequences
Compressed air is considered ‘The Fourth Utility’ because it is vital to the creation of many products we use today. Compressed air is used in the manufacture of many products we consume, including food & beverage. And since it is used in things like food & beverage there needs to be quality controls implemented.
Compressed air is created from atmospheric air. And atmospheric air has multiple substances that can interfere with the product or harm the consumer. Especially in a desert and coastal country like UAE, the atmospheric air can be moisturized and dusty in summer season. If any harm comes to the consumer the entire stock of products must be removed from the market and the manufacturers can be fined or even sued. It will be very costly.
The contaminants that can be found in atmospheric air are:
- Water vapor or hydrocarbon vapor
- Dust and rust particles, dirt, and soot
- Pollutants that affect smell and taste
- Viruses and bacteria
- Liquid oil and oil vapor
- Pipe scale
- Acidic condensates
Testing and classifying compressed air quality
Compressed air is not inherently clean, and usually contains water, oil or other microorganisms. Therefore, for industrial end-products to be devoid of any impurities, it is essential to perform compressed air testing. The testing method is generally classified into:
- Basic testing
- Simple lab testing
- Professional testing
Testing is of paramount importance for any business or application that requires meeting certain air quality standards or is producing quality sensitive products. And to ensure quality of air is delivered to end point its necessary to cross check by doing air quality measurement.
ISO 8573 is an internationally recognized standard that outlines the air quality requirements for industries such as Oil & Gas, Industrial, Environmental, Medical, Pharmaceutical, Petrochemical.
This testing protocol specifies the impurity level of a pressurized gas sample - with particles, water, or oil.
ISO 8573 helps manufacturers select components, designs and measurements for compressed air systems. Quality classes range from 0 to 9 with class 0 having the least number of contaminant particles per m3 of compressed air.
The food & beverage industry, in particular, is standard-aligned to ISO22000, which is a food safety management system. ISO combines the core elements of ISO 90001 and HACCP to implement, monitor and document an above-standard coherent FSMS system.
Businesses with an ISO 22000 certificate adhere to the food safety standards across the manufacturing and the supply chain.
Using the above chart, the compressed air quality can be certified ISO 8573 class 2:4:1 for example which means:
- Dirt: max 400.000 particles in the range of 0.1-0.5 µm, 6.000 particles of 0.5-1 µm and 100 of 1-5 µm
- Water: max 3°C PDP
- Oil: max 0,01 mg/m³
ISO 12500 on the other hand is the standard of how manufacturers test and rate compressed air filters. This includes the testing of coalescing filters for oil aerosol removal, the vapor removal capacity of adsorption filters and testing requirements for particulate filters.
Conclusion
Treating compressed air requires the use of ancillary devices arranged one after another. The devices should adhere to ISO 8573 and ISO 12500 standards.
Each air treatment process causes the pressure to drop slightly, which is sometimes referred to as the ‘footprint’ of the installation. This video demonstration shows how air treatment is arranged and how pressure drops can be minimized.
It’s also advisable to get an air quality audit of your compressed air installation by a professional team. Fill the form below to get an appointment today!
