Factors Governing the Selection of Compressed Air Filters

Compressed air filters are designed to remove airrelative to use and differs widely. Air filters
borne particles from a moving, pressurised airtherefore need to be selected for the properties
stream.that best match the air quality needed to prevent
Compressed air purification equipment is essentialdowntime, systems breakdown or low
to all modern production facilities; at its best, theproductivity. Where air impurities such as viruses,
equipment should provide the optimum balancebacteria or possibly dust from insecticides present
between air quality and low operating cost. Theregreat danger, the selection of filter and filter
are numerous manufacturers offering productsmaterial is of huge importance. The exact grade
for the filtration and purification of air;of air quality required differs therefore, according
compressed air filter costs cover a wide range -to the factors at play.
but initial purchase cost cannot always indicate theDelivering dry, contaminant-free air allows more
effectiveness of a piece of equipment. Inefficient, effective and economical operations.
assessing the suitability of the product, theDamage occurs to plant and equipment when
purchaser will want to assess:water, oil, gases and dust enter into systems
- delivered air quality required by their applicationsuch as pipelines and fittings; compressed air
- environmental impact of usefilters and dryers can help eliminate the conditions
- overall cost of operation over the life of thefor such damage/malfunction.
equipmentIt is generally held that there are 10 major
One way to make these assessments is tocontaminants found in compressed air. Nine of
compare the performance standards of thethese are removed using filtration technology.
different manufacturers' products according toFilter design is based mostly on what works! In
the standards that apply via ISO (the Internationalother words, development is largely empirical -
Standards Organisation) under which there are athe result of experiment and observation. Filter
series of standards covering Compressed Airmaterial design and specification needs to
Quality. There are nine areas of qualitydemonstrate better than adequate retention
classification for the main air contaminants as wellcapacity, separating ability, a stable pressure build
as testing methods for them. The air purityup and low pressure loss.
classifications dictate how much contamination isThe type of material and its weight, the thickness
allowable per cubic metre of compressed air.of layer, loss of pressure at nominal volume flow,
These classifications are used by manufacturersvolume flow per unit of surface and permissible
to rate the air delivered by their products. In thisstatic pressure difference are all considered in the
way, users can easily compare and contrast thespecification of filter material. However, due to
performance of different products. The caveat tothe wide range of locations and conditions in which
this is that the test methods were originallycompressed air is used, these are only
developed to verify air quality in the systemfoundational specifications; there are other
rather than testing the purification equipmentelements that need to be accounted for such as
which means that not all products are tested inchemical and thermal resistance for example.
the same way.In conclusion, compressed air filters have a wide
The selection of the correct air filter forrange of applications and selection of the most
compressed air depends on specific parameterssuitable will depend not only on cost (possibly this
of use and location. Compressed air qualityis the least important factor) but on the
regulations are governed by the widespread andcontaminants to be removed, the operating
growing demands of industry. In manufacturingenvironment, the air quality delivered,
technology (for example, in food and beverageenvironmental impact, and the overall cost of
production, hospitals, electronics manufacturing oroperation over the lifetime of the product.
pharmaceuticals), quality of compressed air is