Air dryers are used for combatting water issues within pneumatic systems. Pneumatic systems can include asco roundline cylinders. Water issues occur when compressors draw in ambient air, which will always contain a percentage of water vapour.
In a pneumatic system, the air is transported from the compressor to an aftercooler which lowers the temperature of the air.
This process causes condensation and there are options are available to remove some water such as coalescing filters. However, if a pneumatic circuit requires extra treatment, air dryers are essential. This is because liquid water in pneumatic systems will create problems such as bacteria growth and corrosion, which can lead to lethargic controls or component breakdowns.
Different types of air dryer can include;
Refrigerated Air dryers
Refrigerated air dryers remove water from pneumatic circuits by reducing the compressed-air temperature and therefore causing condensation. The liquid is then collected by an internal separator and it is sent to a drain.
Desiccant air dryers
Desiccant air dryers work by adsorbing excess moisture from the air flow onto a dehydrated material in a shifting process. These air dryers are ideal for below freezing conditions, or when procedure requires particularly dry air. Desiccant air dryers can come in both heated and heatless options.
Membrane air dryers
Membrane air dryers rely on a specially engineered permeable membrane, and with the help of pressure differences inside the dryer, molecules of water vapour in the air can pass through the tiny holes in the membrane; larger nitrogen and oxygen molecules cannot.