Ambient air can be compressed and used as a compressed air source; dryers help reduce moisture and humidity levels. Because of this, they form an integral part of your air system. Air is completely saturated as it leaves your compressor, which can lead to contamination and corrosion. Your airing system, pneumatic tools, and final products will be contaminated and rusty. Compressed air dryers are necessary to meet high requirements for the air quality of the section.
The food and beverage, electronics, manufacturing, and automotive paint industries are some examples of places where electrostatic precipitators are used. This brings us to the question: how do you identify which of the compressed air dryers is right for you? A few primary considerations will ensure you choose and make a proper decision…
These air dryers are sized according to your ambient temperature, the incoming air, and the size of your air compressor. A dryer's capacity is directly proportional to the compressor's power consumption; in simple terms, if your compressor is big and draws a lot of power, then your dryer must also be big enough to deal with a large flow. Lastly, it would be best to go for a dryer that corresponds with the exact temperature in your surroundings and the air quality required in your particular procedure.
In some industries, the compressed air quality can be relatively high on the list of requirements. They need air with their desired dew point. This means that water vapor is the process that condenses at the below temperature and forms water. These high-quality air applications require the dew point of their compressed air below and – more importantly – stable. Nevertheless, dew point should only be applied to those who employ compressed air in such applications. For instance, firms that only require the humidity level to avoid water condensation in their pipes and tools are well provided for in the term relative humidity.
The dew point fluctuates with constant relative humidity over the year because the ambient temperature is not constant. That would not be acceptable for critical applications, and at least it would not make the occupants miserable or soaked due to condensation. First, it can be risky weather conditions only in the winter, so a higher PDP is admissible in the summer. Or, if the sensitive time is in the summer, then a negative PDP is required in the winter. It is more important to emphasize that this only applies to condensation prevention.
There are many varieties of air dryers, and each has been developed to address specific uses and needs. Here are the most common types of air dryers:
Refrigerated air dryers are the most common type of air dryer used across all industries and applications. They act like the refrigerator in your house, cooling the air inlet to the level at which water in the moist air condenses. This water is then drained out, leaving the air dry. Refrigerated air dryers are usually applied in various corporate operations where there may not be such strict demands regarding low humidity.
A refrigerator is also one of the more commonly used industrial air dryers, mainly because it is more efficient and comparatively cheaper. A refrigerator's core role is thus to lower the temperature of the compressed air, which causes water droplets to form and be eliminated.
Membrane air dryers, therefore, operate based on an ability known as selective permeation. In this, compressed air is forced through a membrane while water vapor and all other impurities seep through the wall of the membrane, and the dry air passes through them.
Compressed air dryers are available in packaged units that can be fixed either indoors or outdoors and differ from each other in their design and efficiency. In these systems, moisture is not eliminated through temperature alternation or the effects of chemicals; instead, it is separated from the air through special membrane material.
In other words, the correct dryer size should dry air at a rate equal to whatever rate your compressor delivers air to meet the demands of your process. As with everything else operating with compressed air, there are ways to calculate the suitable dryer, and it is unwise to rely on memories or interchanges following what was previously used. Ultimately, there are primary factors to consider when selecting the proper dryer:
The maximum air velocity is defined in standard cubic feet per minute.
Desired pressure dew point
Inlet compressed air pressure
Inlet air temperature
Air temperature surrounding the condenser and water temperature (in case the condenser uses water). From a traditional perspective, desiccant dryers should offer a dew point as low as -40°C / -40°F. Some applications that can significantly benefit from the air with a consistent and predictable dew point include those industries with exceptionally high demands like piping often exposed to freezing, pharmaceutical industries, food processing industries, and others requiring very high air quality. Usually, refrigerant dryers achieve a dew point of about three °C / 37°F. However, desiccant dryers are costly due to energy consumption and media replacement. A refrigerated air dryer would suffice well for applications requiring only dry air, but the critical dew point is not an issue.
Compressed air dryers are always advisable, depending on the system's requirements. For this reason, selecting the right dryer for your business is critical to ensuring smooth processing and avoiding any interruptions that faulty dryers may cause.
