How to choose the right suitable dryer？

If you have ever used an air compressor before, there may be times that you noticed some water droplets in the air distribution system. Moisture in the air compressor system is never a good sign because it leads to corrosion. And corrosion damages various parts of the air compressor or may lead to a complete breakdown if the damage is not alleviated as soon as possible.

The best to prolong the lifespan of the air compressor and save yourself on costs of repair and maintenance, you need to have an alternative way of keeping the moisture out of the air compressor. An air compressor air dryer is the solution you need for this task. Here is some useful information on things you should know about the air compressor air dryer.

Moisture Everywhere!

The formation of moisture in the air compressor system is unavoidable since water if part of natural air. It is even evident every morning as dew on the grass. Moisture easily forms when air is compressed. In technical terms, if the air is subjected to increased pressure, the dew point goes up. The dew point is the temperature at which air becomes more saturated with moisture. If the temperature drops below the dew point, the water molecules condense.

How air dryers work

Most of the methods of drying compressed air involve the manipulation of the dew point. As long as the dew point is low enough, water vapor will not condense. This is how almost every air compressor air dryer works. There are other ways you can use to reduce the amount of moisture in the air compressor system before you use an air dryer.The first thing you need to do is to ensure you drain water from the tank frequently as part of your maintenance.

Another step involves the use of anaftercooler.The aftercooler works in the same way as a car radiator, which is cooling the air to make sure moisture is condensed. The moisture is then drained using a water trap. Most air compressors come with an integrated aftercooler. Other ways of drying water in an air compressor include the use of pressure regulators and coalescing filters.

Air compressor air dryers come in a wide variety of types, and the most common type is the refrigerated air dryer and the desiccant air dryer.Different types of air compressor air dryers achieve varying dew point levels.

 

Refrigerated Air Dryer

The refrigerated air dryer is the most affordable and effective method of drying air produced by an air compressor. There are two types of refrigerated air dryers, namely cycling and non-cycling.

Cycling air dryers are flexible and allow the system to auto turn on and off depending on the amount of compressed air and pressure in the system. On the other hand, the non-cycling air dryers remain on regardless of the air load in the system.

Refrigerated air dryers work in the same way as aftercoolers. They work by cooling air to condense the moisture and trap the water before it is removed from the system.Aftercoolers can be either water-cooled or air-cooled. On the other hand, refrigerated air dryers use refrigerants to reduce the temperatures in the system.

Refrigerated air dryerssometimes low the dew point of compressed air to somewhere between 3 and 5 ºC), which is okay in various applications.

Desiccant Air Dryer

Have you ever seen desiccants inside a bag of chips or in medicine containers? Well, the desiccant air dryer works in the same way. They attract water and therefore helps in removing moisture from the air compressor system.

Compressed air is often passed through vessels that are filled with desiccant materials, which are mostly silica gel or alumina. These desiccant materials absorb moisture from the air compressor system.

Desiccant air dryers can reduce the dew point to temperatures between -40 ºF and -40 ºC. This dew point is suitable for pneumatic tools, such as spray painters and print jobs.

Desiccant materials become saturated with moisture over time and require to be replaced after one year.

An air compressor air dryer is an essential component that keeps the air compressor safe from the effects of water molecules. The overall performance of an air compressor depends on how much moisture is kept out of its system. And air dryers work to keep moisture out of the system.

Why do you need an air compressor air dryer?

As said earlier, moisture creation in an air compressor is unavoidable, but if it is maintained well, it can prevent a lot of damage to any pneumatic equipment. To avoid unnecessary costs of maintenance, you need to takethe right step by having an air compressor air dryer.

Choosing the right air compressor air dryer depends on the specific requirements and tolerance to moisture levels of your air compressor. Most manufacturers of air compressors can achieve various requirements using a refrigerated air dryer, while other equipment, such as spray painters, need desiccant air dryers to get the work done.

What are the differences between cycling and non-cycling refrigerated air dryers?

Refrigerated air dryers are best for all applications that require dry air but do not require any critical dew point. Additionally, this type of air compressor air dryers is more cost-effective and comes in two variations, as mentioned earlier.

Non-cycling air dryers

The refrigerated non-cycling air dryeris a great starting point for anyone who wants to improve the quality of their compressed air but is working on a tight budget. This type of refrigerated air dryer runs in the refrigeration compressor continuously and uses the hot gas bypass valve to redirect the refrigerant even when the load is not full. This air compressor air dryer works by lowering the air temperature to 3° Celsius. This temperature allows water to drain off the system while still in the vapor state, leading to dry air, which is essential in various applications. Non-cycling air dryers are more reliable and usually simple machines. Accordingly, they come with minimal design to simplify the equipment’s usability and operations.

This type of refrigerated air dryer is less costly and provides dry, clean compressed air. Generally, non-cycling air dryers are easy to use since they are the market standard in terms of performance, reliability, and quality in delivering the desired results.

An ideal pairing of the non-cyclingair dryer is the rotary screw air compressor. However, a higher temperature version of this air dryer is suitable in piston air compressors. As the name suggests, non-cycling air dryers run continuously regardless of the load (pressure of compressed air coming through). This also means that the energy consumption of this air dryer is nearly the same, whether the load is full or not. Therefore, it is more energy-efficient compared to other options in the market. If energy-saving is among the factors you prioritize and you need a simple air compressor air dryer that guarantees minimal dew point swings, then you should opt for a non-cycling refrigerated air dryer.

Cycling Air Dryers

Cycling air dryers utilize various equipment, such as frequency controllers and thermal mass, which allow the machine to auto turn off or on, depending on the amount of a load of compressed air coming through the air dryer. This specification also makes the air dryer energy-efficient. Cycling air dryer comes in a customer-oriented design and reliable performance. The cost of purchasing the air dryer is, however, higher compared to a non-cycling air dryer.However, it offers the best long-term solution and low life-cycle cost.

Cycling air dryers are equally reliable and convenient with easy installation and low noise production levels. As mentioned earlier, cycling air dryers offer the most energy-saving solutions and low-pressurepoints. The advantages of this air dryer pay for the cost drawback and make it more beneficial and useful in every air compressor unit. The cost of the machine in regards to its life-cycle is understandable, especially if your kind of applications require fluctuating air demands.

Advantages of integrated air dryers

Most companies are usually faced with the challenge of optimizing their air compressors due to limited space. With the limited space, manufacturers tend to offer integrated refrigerated air dryerson air compressors to meet the demands of dry compressed air. An integrated air dryeris handy when it comes to removing moisture from compressed air to prevent the air compressor from moisture-related damage.

The option for an integrated air dryer in the air compressor not only eliminates the space challenge but also offers more savings on the cost of installation, while at the same time offering quiet and reliable solutions for all your dry, compressed air needs. It is essential to consult your air compressor air dryer manufacturer or dealer when buying any machine to ensure you know everything necessary.

The most significant factor that can be used to draw a line between refrigerated and desiccant air dryers is the desires dew point. As stated earlier, a refrigerated air dryer is capable of providing a dew point of between 3 and 5°Celsius. This temperature is sufficient enough for most industrial applications. On the other hand, if your projects require high-quality compressed air, then you should opt for a desiccant air dryer. Desiccant air dryers can achieve somewhere near -70 °C, which is a standard temperature that guarantees the cleanest and driest compressed air.

Contrary to refrigerated air dryers, desiccant air dryersuse desiccant beads (materials) to absorb water vapor from the compressed air leaving the air dry and clean. In the process of absorbing the water vapor, water molecules adhere to the desiccant materials without changing their composition. Once the desiccant materials are saturated with moisture from compressed air, the regeneration process occurs via dry purge air, heat, or a combination of both to dry the materials. Alternatively, other types of desiccant air dryers need replacement of desiccant materials once they are saturated. In most cases, the desiccant beads can be replaced after one year.

Desiccant air dryer options

Regenerative desiccant dryersare mostly meant to provide a standard dew point of between -20 °C and -70 °C. however, this specification comes at the cost of purge air that must be accounted for in the air compressor system. There are many types of regeneration processes in desiccant air dryers.The models all depend on the amount of purge air that is used up in the process of regeneration. For instance, higher purge calls for larger air compressors, which result in more power consumption and high cost in terms of the life cycle.

There is also another option, which is the heatless desiccant air dryer. This type requires between 16% and 25% purge air and is among the most cost-effective one. However, it is also less efficient. when buying a heatless desiccant air dryer; you should consider accounting for the additional purge air when sizing your air compressor.

Heated purge air desiccant dryerscan use internal or external heaters to take the place of the bead drying process. Heated desiccant air dryers reduce the amount of purge air required for the operation of tower regeneration to less than 10%. This type of air dryer requires high initial cost because of its design and the ability to reduce purge air. However, the air dryer offers energy-efficiency solutions during its entire life span.

Heated desiccant air dryers that use external heaters heat the purge air to higher temperatures before introducing it to the desiccant materials for drying and the regenerationprocess. The process can use an average of 0-4% purge air and is, therefore, one of the reasons why the externally heated desiccant air dryer is one of the most efficient air dryers.

The bottom line

The need for an integrated air dryer in the air compressor depends on the specific air quality requirements for every given application. Additionally, the choice between a refrigerated and desiccant air dryeralso depends on your needs. Air dryers play a crucial role in ensuring that you get dry air, which is suitable for various industrial applications. Investing in the right air-drying solution for your air compressor can go a long way in saving you some costs in maintenance.