Types of Air Dryers for Different Needs

Air dryers are essential features in industries that require the use of an air compressor due to the moisture that it produces. While the excess moisture can be drained, it can’t be entirely removed. Water often sticks around as a vapour or aerosol, making it challenging to remove. Even the slightest amount of moisture in the system could cause corrosion and bacterial growth, which can result in sluggish processes or lead to breakdown of equipment. The right air dryer on the other hand, will be able to keep moisture out and extend the life of your compressors. 

Unsure of which air dryer to choose for your business needs? We take a look into some commonly used air dryers in the market and the best applications for each one.

Refrigerated air dryers

Refrigerated air dryers work on the principle of condensation. These air dryers cool compressed air to very low temperatures allowing moisture suspended within such that it condenses into its liquid form. After the water has been removed, a dry stream of air can then flow onwards to applications that require it.

Refrigerated air dryers come as cycling or non-cycling variants. Cycling refrigerated air dryers operate similarly to standard refrigerators supplying variable cooling according to the demands. Non-cycling units provide constant cooling independent of demands, but this also causes them to be a less efficient option. 

Often used in several manufacturing and service applications that require compressed air with no detectable moisture, refrigerated air dryers are not suitable for highly sensitive applications where even little quantities of water can be detrimental.

Learn more: How Does a Refrigerated Air Dryer Work?

Membrane air dryers

Used as dehumidifiers or for applications that require gas separation, membrane air dryers direct the compressed air across bundles of semi-permeable membrane fibres. Such air dryers are ideal for single points-of-use or smaller projects, and can be used in applications requiring dehumidification, food processing, and gas separation. While they might be easy to operate and maintain and do not require electricity, membrane air dryers need frequent changing of the prefilter for effective functioning.

Chemical air dryers

Chemical air dryers utilise hygroscopic materials to achieve moisture removal from pressurised air. A typical setup is a drying unit that contains calcium chloride or lithium bead which draws moisture out of the air stream that passes through it. In addition, high-quality coalescing and particulate filters are often added to prolong the lifespan of the drying material. Such air dryers are often integrated in moisture-sensitive chemical manufacturing and food processing applications.

Desiccant air dryers

Desiccant air dryers also use hygroscopic materials such as silica gel and activated alumina to achieve air drying. The absorption setup usually comprises a twin tower drying system with both chambers filled with desiccant materials. During operation, one tower is actively drying air channelled through it while the other is in a regenerative state. Both towers switch between drying and regenerative phases throughout the operation cycles. Desiccant air dryers are advantageous in moisture-sensitive industrial and commercial applications, including mould prevention, food processing, healthcare or medication prescription environments, and more. 

Air dryers are crucial in maintaining reliable operations of downstream equipment. We hope this article has given a better understanding of these commonly used air dryers, and provided more insight into which one would suit your business.

GWT Enterprise is an established air compressor and air receiver tank supplier in Singapore with a wealth of experience in the field of compressed air. No matter what your needs are, you can rest assured we have something that will suit them. Reach out to our team today to find out more!