Compressed air is a safe and reliable power source that is widely used throughout industry. Often referred to as the fourth utility, approximately 90% of industry uses compressed air in some aspect of its operations. 

Whereas gas, water and electricity are supplied to a site by a utilities supplier, conforming to strict tolerances and quality specifications, compressed air is generated, on-site and on demand. As a result, the quality of the compressed air and the cost of producing this powerful utility are the responsibility of the user which means the provision of good, clean and dry compressed air should be of prime concern.

Contaminants

The contaminants in a compressed air system must be removed or reduced to acceptable levels if the system is to operate safely, efficiently and cost effectively. Typically, these contaminants can be split into three categories; solid particles (Including viable and non-viable microbiological organisms), water (vapour, liquid and aerosols) and oil (vapour, liquid and aerosols).  These can then be separated in to two further categories, which focus on the additional contamination that is inhaled from the atmosphere. These are derived from ambient pollution (water and oil, both as vapour and particles) and from any pollution within the compress air system itself (water and oil, as liquid, aerosols, vapour and particles).

To help users gain a better understanding of these contaminants and, importantly how to remove or treat them, BCAS and its Air Treatment and Applications’ committee are producing a good practice guide (GPG216-1). Called ‘The Filtration and Drying of Compressed Air’, the guide will help facilities managers identify the various steps to take and procedures to implement to enable the safe and reliable application of clean, useable compressed air.

The guide, which is due for publication later in 2018, will establish the range of different technologies available when selecting equipment for compressed air purification systems; typically for low pressure applications of around 7 bar g to 20 bar g. 

The selection of the right equipment can be a complex task, affecting everything from maintenance schedules to the ongoing costs associated with achieving the required standards, while avoiding generating excessive purge air and preventing significant pressure drops. As a result, the guide sets out to demystify the specification process, providing practical guidance on selecting the most appropriate form of air treatment.

It will also help the end user in the selection of appropriate filtration, while explaining the design characteristics of the many different types of compressed air dryers and their specific usages, allowing for the easy identification of product types required for differing applications.

Also included in the guide will be information relating to the ISO compressed air standards relevant for the production of such commodities as food, pharmaceuticals and specialist electronics.

The guide will also include sections on equipment selection criteria, total cost of ownership, condensate management, breathing air, dental air and performance validation of compressed air purification equipment.