Deciding what type of air dryer is right for your application can be paramount to the success of your business. If you select the wrong type of dryer, you risk paying more money for a system that doesn’t fit your needs appropriately and may also negatively impact the efficiency of your entire system. When choosing between a refrigerated air dryer and a desiccant air dryer, you must keep a number of things in mind and understand about each dryer system.
What is a Refrigerated Air Dryer?
Like most types of compressed air dryers, refrigerated dryers can be utilized in a variety of industries and applications to remove excess moisture from the air that has been compressed. If compressed air isn’t properly dried, the moisture present in the air can cause issues with tools and equipment, leading to production downtime and impacting product quality.
Refrigerated dryers work by lowering the temperature of the air almost to the point of freezing, at which point the air condenses and is then removed from the system via drainage. First, a heat exchanger within the dryer cools down the air, causing it to condense. After the air has been cooled, it passes through an air-to-air heat exchanger, where it is reheated using outgoing cold, dry air, which helps limit temperature swings, preventing moisture from building up on the dryer’s exterior. Moisture then passes through a separator, which collects and removes the liquid. One of the last main components of a refrigerated air dryer is the refrigeration compressor, which pumps refrigerant throughout the system, allowing it to maintain an appropriate temperature during operation.
There are two primary types of refrigerated air dryers: cycling and non-cycling. Cycling dryers turn the air dryer system on and off depending on the demand for compressed air. These machines are designed for applications with varying levels of air demand. On the other hand, for applications requiring a steady supply of dry air, non-cycling dryers continuously run regardless of demand, providing constant drying. While these types of refrigerated dryers consume more energy than their cycling counterparts, non-cycling systems are ideal for applications with a high demand for dry air.
The most common industries that use refrigerated air dryers include manufacturing, pharmaceuticals, food and beverage, and automotive sectors. These industries are held to some of the highest purity and cleanliness standards, so they must ensure their products and equipment are totally moisture-free.
What is a Desiccant Air Dryer?
Desiccant air dryers are utilized in industrial applications for the same reasons refrigerated dryers are: to remove moisture buildup from compressed air sources and prevent issues with damaged tools or impacted product quality. However, the way desiccant dryers accomplish that task is a bit different than refrigerated dryers.
Desiccants are substances that can take in moisture from the surrounding environment. You’ve likely encountered desiccants in various packages or product boxes; one of the most common desiccants is silica gel or silica beads. However, many more types of desiccants can be used in desiccant air dryers, some of which you may also be familiar with. Activated charcoal, calcium chloride, calcium sulfate, and zeolites are all known for their ability to remove moisture from solids as well as gases, like air.
Desiccant dryers are most commonly designed to be regenerative in nature, meaning they can renew their desiccant material by reversing the adsorptive process. These types of desiccant dryers have an additional tower packed with desiccant material, allowing absorption and regeneration to happen simultaneously, thus enabling the dryer to run continuously. Desiccant air dryers are found in a variety of industrial settings, including oil and gas applications.
Knowing What is Right for Your Application
When choosing which of these dryer options is right for your specific use, it’s important to keep a few things in mind:
- Initial Investment: Be mindful of how much money you have to spend upfront on your new dryer. While refrigerated dryers require less capital investment and are known for their low operational and maintenance costs. Desiccant dryers, on the other hand, come with a higher initial investment.
- Dew Point Requirements: Applications requiring a dew point of lower than 35 degrees Fahrenheit will likely want to opt for a desiccant air dryer, which can operate in conditions significantly lower than freezing.
- Industry Type: Different industries typically prefer one type of dryer over another. For instance, most food and beverage industries will utilize refrigerated dryers, as they are able to achieve a higher level of purity when compared to desiccant dryers.
ESA For Your Air Dryer Needs
If you need assistance deciding which type of compressed air dryer is right for you, contact the professionals at ESA. With decades of knowledge, a wealth of on-site experience, and 24/7 availability, our trained staff members are here to help you make the best decision for your business.