Air dryers are used downstream of an air compressor to rid the compressed air of any moisture or humidity before it reaches your application or final product. Using air dryers is imperative in many applications such as the food/beverage industry, electronics, manufacturing and spray painting in the automotive industry.
But how do I know which type of air dryer I need for my specific air compressor?
Air dryers are sized based on your ambient temperature and incoming air, as well as the capacity of your air compressor. The larger the HP of your compressor, the larger the flow will need to be on the dryer. Most importantly, you want to choose the right dryer based on the temperature of your environment and the quality of the air which you need for your applications.
Not all end users are better served with air delivered at a specific dew point. You can say they are over served. Only end users who use the air in special applications where actual water content is critical should use dew point. Customers who just want to prevent condensation of water in their pipelines and tools are well served with the term Relative Humidity. Since the ambient temperature over the year fluctuates, a constant relative humidity results in a fluctuating dew point.
Therefore for a customer who only needs to have a condensation prevention having costant PDP throughout the year is certainly an over demand. Either the critical condition is in the winter, which means that a higher PDP is okay in the summer. Or, the critical condition is in the summer, then a negative PDP is required in the winter.
Note again that this is only the case to prevent condensation. We already mentioned before that in case of special applications where water content is more important than free water in the air system you need a fixed PDP the entire year around.
If the ambient temperature is less than 40° C and main usage of a dryer to prevent condensation or having dew-point around 3-4° C, a refrigerated dryer is best to use. These dryers are often used in manufacturing plants, auto shops, food manufacturing and breweries. Refrigerated dryers come in both cycling and non-cycling variants to fit the need of your application. These dryers are energy efficient and are the most popular dryer type.
If the ambient temperature and incoming air are over 40° C, typically a high-temp dryer is recommended or using an after cooler after the compressor is advised.
If you need a high level of dry ambient air (PDP of -40° C or -70° C) an adsorption dryer would be used. Adsorption dryers can reach pressure dew points as low as -70° C and are often used in very cold climates to avoid ice forming in pipes and applications. Adsorption dryers are also used in applications such as mold prevention, medical applications, textiles and food factories to keep the air as dry as possible. These dryers use desiccant material (similar to the non-edible packs you find in your newest shoebox) to adsorb and remove the humidity from compressed air. Adsorption dryers also come in different technologies such as Heatless Dryer, Heated purge dryers or Blower Purge/Zero Purge dryers.
Air dryers are recommended for almost all compressed air applications, but determining the right dryer for your business it is important to keep your production running as safely and efficiently as possible. To browse Pneumatech's dryer product lines, click HERE.