What Are The Main Compressed Air Dryer Types?

There are 4 main compressed air dryer types: refrigerated compressed air dryers, chemical compressed air dryers, desiccant compressed air dryers and membrane compressed air dryers. Find out more about this type of compressed air treatment below.

Refrigerated Compressed Air Dryers

Refrigerated compressed air dryers cool the air to low temperatures and condense the water vapour. With refrigerated compressed air dryers, it is not possible to realise dew points below freezing. A modern refrigerated compressed air dryer can produce air with dew points as low as 2 °C. As some water vapour is left in the air, a refrigerated dryer is not suitable for water vapour-sensitive applications such as pharmaceutical and electronic manufacturing.

Desiccant Compressed Air Dryers

There are two types of desiccant compressed air dryers: heated and heatless.

Desiccant compressed air dryers pass the compressed air over a bed of desiccant material which absorbs the water vapour. When the bed capacity is nearly saturated, the airflow is moved to another bed of desiccant material whilst the first bed is regenerated.

Heated desiccant dryers use heat to remove water vapour from the desiccant material, which requires a large amount of steam or electricity.

Heatless dryers, on the other hand, use the dry air generated by the dryer to remove the water vapour.

To regulate the regeneration timers and minimise energy usage, dewpoint monitors are used. These dryers are most common for high-quality air applications with very low air vapour requirements. They are also suitable for when compressed air is subject to freezing conditions as the dewpoints go as low as -70°C.

Membrane Compressed Air Dryers

Membrane Compressed Air Dryers utilise specially formulated membrane microtubes that are selectively premeable to water vapour: as the compressed air travels along the membrane the water vapour passes through the membrane leaving dry compressed air. A small stream of dry compressed air is pushed along the outside surface of the membrane to move away the moisture-laden air.

A membrane compressed air dryer can operate as low as -40°C and they are favoured as they have no moving parts, require very little maintenance, and operate with minimal noise output.

Membrane Compressed Air Dryers are even explosion proof so they are ideal for remote locations, freezing environments and where a consistent dewpoint is needed. The downside, however, is that they are expensive to buy and not very economical at higher flow rates.

Choosing the correct Compressed Air Dryer Types for You

Choosing the right compressed air dryer needs careful consideration. It is important not to over-specify and look for a dryer that will not be wasteful. But on the contrary, it is important not to under-specify, risking the dryer not performing well will damage expensive machinery and cause downtime. There are many factors to consider, which are different for each application and use.

Glaston’s Services

Glaston has provided air compressor design & installation services, as well as air compressor maintenance for nearly 40 years. Our team of professional, qualified and experienced compressor engineers provide bespoke compressed air solutions which are tailored to each of their customer’s specific needs.

Glaston knows it is important to make sure that a compressed air system is meeting the needs of the business, and works in the most efficient way possible. Glaston will analyse the lifetime costs of machines, rather than just the initial costs; taking into consideration running costs, maintenance costs as well as initial set-up and machinery costs. Choosing the air compressor systems and dryer that will work for you.

For more information about Glaston’s air compressor services, contact us today. We can also help you find suitable nitrogen generation equipment and vacuum blowers for your business.