The 6 Most Common Compressed Air Drying with 4A molecular sieve Methods

Water is a challenge in every air compressor system with 4a molecular sieve. As air is compressed, water is created in the air stream. During cooling, that water condenses and mixes with the compressed air delivered to your tool or application. Some water is okay for most applications, but too much water can be a problem. That’s where compressed air drying comes in!

There are six common ways of removing or reducing the amount of water in a compressed air stream. The common compressed air drying methods are:

Aftercooler

Air-Cooled

Water Cooled

Storage Tank Cooling

Membrane Type Dryer

Refrigerant

Deliquescent / Absorption Drying

Regenerative / Adsorption Drying

Dual Tower Regenerative Desiccant Air Dryers

Each of these drying methods is unique, with its own benefits and disadvantages. This article will explain each standard air drying method in more detail.

Aftercooler Method

In the aftercooler method, a heat transfer will occur between two bodies of different temperature air until temperature equilibrium is reached. This transfer of heat can take place in three different ways and, generally, these take place simultaneously:

Conduction

Convection

Radiation

Aftercoolers use this principle to balance the temperature of compressed air with atmospheric air, and some moisture separation also occurs within the process.

An aftercooler is a heat exchanger used to cool compressed air and minimize moisture within the system. Reduced compressed air temperatures cause water droplets to precipitate out of the air. These liquid contaminants are typically collected and drained off with a moisture separation device and drain trap (mechanical or timed).

Figure 1. Typical mechanical float-type drain trap

Figure 2. Typical electrically timed drain trap

Aftercoolers are a popular choice for mobile air compressors and can also be used in stationary applications. The aftercooler should be located as close as possible to the compressor outlet.