Time to consider the true cost of filtration

 

Compressed air purification equipment is essential to all modern production facilities. It must deliver uncompromising performance and reliability while providing the right balance of air quality with the lowest cost of operation.

 

The primary reason for using a compressed air filter is to remove contamination and improve air quality. There are generally considered to be 10 major contaminants found in compressed air, of which nine are removed using filtration technology. At Parker we categorise filters into five groups:

 

Water separators

Water separators are used to protect coalescing filters against bulk liquid contamination, where excessive cooling takes place in air receivers and distribution piping.

 

 

Coalescing compressed air filters

Coalescing compressed air filters are probably the single most important items of purification equipment in a compressed air system. They are designed to not only remove aerosols (droplets) of oil and water using mechanical filtration techniques, but to remove solid particulate to very low levels (as small as 0.01 micron in size).  Installed in pairs, the first compressed air filter is a 'general purpose filter' which protects the second 'high efficiency filter' from bulk contamination.

Adsorption (activated carbon) filters

Oil vapour is oil in a gaseous form and will pass through a coalescing filter just as easily as the compressed air.  Therefore, oil vapour removal filters must be used as these provide a large bed of activated carbon adsorbent for the effective removal of oil vapour, providing a very high level of protection against oil contamination.

 

Dust removal filters

Dust removal compressed air filters are used for the removal of dry particulates. They provide identical particulate removal performance to the equivalent coalescing filter and use the same mechanical filtration techniques to provide up to 99.9999% particle removal efficiency.

Sterile filters

Absolute removal of solid particulates and micro-organisms is performed by a sieve retention or membrane filter. These are often referred to as sterile air filters as they also provide sterilised compressed air. Filter housings are manufactured from stainless steel to allow for in-situ steam sterilisation of both the filter housing and element. Piping between the sterile filter and the application must be cleaned and sterilised on a regular basis.

The quality of air required throughout a typical compressed air system will vary depending upon application. Treatment of the compressed air at only one point alone, for example the compressor room, is not enough and it is recommended that the compressed air is first treated prior to entry into the distribution system (to a quality level suitable for protecting air receivers and distribution piping) and then at point of use, with specific attention being focused on the application and the level of air quality required. This approach to system design ensures that air is not 'over treated' and provides the most cost effective solution to high quality compressed air.

 

So, are all filters the same? 

 

Compressed air filters are often bought with a compressor; as part of a package deal and therefore selected based upon purchase cost, with little or no regard for the delivered air quality or total cost of ownership.  

If the running costs of a filter are analysed, then typically the differential pressure (dP) values printed in literature will be used. However, these values are only representative of the filter in an 'as new' condition, and do not take into consideration the initial and on-going blockage characteristics of the filters, which can vary significantly.

 

 

Calculating the true cost

In comparative testing of Parker OIL-X EVOLUTION filters against five commonly available alternative filters, the blockage characteristics and therefore the true differential pressure of each filter can be demonstrated. This data can then be used to calculate a realistic life time cost for each filter.

 

 

Use of electricity has a direct impact on the generation and release of CO2. By reducing energy consumption, efficient filtration helps to reduce the carbon footprint of a manufacturing facility and protect the environment.

 

Parker continually develops its filtration ranges to ensure that every compressed air filter it delivers offers the right balance between filtration performance and energy consumption, resulting in a reliable compressed air system with low total cost of ownership