What Is Air Drying Process?

Water vapor is present in atmospheric air, but as air is compressed, the relative humidity of water rises to the maximum. Hence, compressed air must be dried to avoid difficulties caused by water precipitation in pipes and downstream equipment.

Compressed air dryers are necessary for a variety of industrial settings where dry compressed air is required on a regular basis. Because moisture in industrial air can harm pneumatic systems, cause pipelines to freeze, and encourage corrosion in metallic parts, these dryers are vital in industrial operations.

In this article, we will discuss various air drying techniques in detail.

Applications of Air Drying

The process of using air to remove moisture from surfaces and coatings involves the concept of air drying. Rusting and corrosion, which can be caused by excess moisture, are prevented by this process. Several air-drying paints and coatings are made using this technique. It also aids in the removal of moisture, which can damage the color and finish of coatings and paints.

Natural oils like linseed and soybean oils can be dried by air. They use chemicals in the compounds that allow oxygen from the air to be absorbed, resulting in spontaneous polymerization. This can be accomplished by applying a specific pressure to dry air or gases such as nitrogen.

Enhancing and drying of paints or coatings is another way to improve corrosion protection in metals. This necessitates determining the type of resin or polymer that can dry in the presence of air. This method is used to create chemicals that dry quickly at low temperatures while also lowering the amount of Volatile Organic Compounds (VOC).

When paints or oils are preheated in the presence of catalysts, the process of air drying is utilized. As a result, the type of resin or polyester employed determines whether corrosion protection substances should be dried by air or by heat. The choice of film thickness is critical for this approach to work.

What is an Air Dryer?

A compressed air dryer is an equipment that is used to remove water vapor or moisture from the industrial process air. This process is also known as dehumidification. This is an important aspect of industrial business.

A compressor sucks in humid air and compresses it, raising the air temperature and then cooling the air condensing water vapor out of the unit in a typical system.

There are, however, different options for achieving separation. The refrigerated, desiccant-type, and membrane types of air dryers are the most common.

Methods for Drying Compressed Air

Every air compressor system has a water problem. Water is introduced into the air stream as air is compressed. Water condenses during cooling and is combined with compressed air provided to your tool or application.

For most purposes, a small amount of water is sufficient, but too much water might be problematic. This is where the use of air drying comes into play.

There are six common methods for removing or decreasing water from the airstream. The following are the most prevalent compressed air drying methods:

Aftercooler Method

This technique is used in aftercoolers to balance the temperature of compressed air with ambient air, and some drying happens as well.

A heat exchanger used to cool compressed air and reduce moisture in the system is known as an aftercooler. Water and oil droplets precipitate out of the air as compressed air temperatures drop, and these liquid impurities are normally collected and discharged using a moisture separation device and drain trap.

Storage Tank Cooling

When air flows from the compressor or is carried over from the aftercooler, the storage tank cooling technique of drying air uses an air receiver tank to transform some of the air moisture into water droplets.

Refrigeration Drying

Due to their ease of maintenance and relative cost-effectiveness, chilled air dryers are one of the most prevalent types utilized in industrial applications. They can be used for air-drying without any additional conditions, such as a low dew point.

The working idea of a refrigerated air dryer is to dehumidify air by rapidly cooling it, condensing it, and draining the moisture. The operation is similar to that of a home refrigerator or air conditioner.

Absorption Drying

Absorption is another typical method for drying air. In absorption drying, incoming air enters the tank towards the bottom and is separated mechanically. The liberated liquids and solids fall to the bottom of the vessel due to expansion. To some extent, this is a form of air pre-drying.

The air is then drawn into the desiccant bed, which is made up of deliquescent ingredients such as water-soluble salts. As they dissolve the liquid, these hygroscopic substances (like zeolite) condense water vapor.

The deliquescent elements are used until they are totally consumed. These elements are then replaced. It is recommended to find online dealers offering zeolite 13x pellets for sale.

Adsorption Drying

Adsorption dryers function on the simple idea of wet air flowing through desiccant materials to dry them. The desiccant material is renewed once it absorbs water and regains its drying capacity.

Adsorption dryers are usually constructed with two drying vessels, the first of which is used to dry incoming compressed air while the second is used to replenish it.

Using Membrane Type Air Dryers

These dryers make use of semi-permeable membranes. The compressed air is passed through these tiny membrane fibers. By doing this, the water vapor and humid part of compressed air move from high concentration to an area of low concentration through the membrane, and dried air flows downstream.

The separated water vapor is purged out of the membrane by emitting high-pressure compressed air (also known as sweep air).

This article discussed various techniques that are used for air drying. Drying compressed air is important for various processes. Different methods can be implemented as per variable cost, quantity requirements.