refrigerated compressed air dryer

Types of Refrigerated Compressed Air Dryers

A refrigerated compressed air dryer is a device used to reduce the temperature of compressed air in order to remove moisture from it. Refrigerated compressed air dryers come in two main types: cycling and non-cycling or constant models. Both work basically the same way. Warm, wet compressed air passes over a refrigerant-filled evaporator coil in the dryer, which cools the air. As the air cools, moisture in the air condenses, forming water that is then blown out through an auto-drain.

A cycling refrigerated compressed air dryer includes a compressor that works to regulate the refrigerant's pressure, enabling the dryer to adjust its cooling cycle and function efficiently. On the other hand, a non-cycling or constant refrigerated compressed air dryer maintains a constant coolant flow inside the coil.

• Cycling Refrigerated Compressed Air Dryers: Cycling air dryers are designed to conserve energy by reducing their cooling power when the inlet temperature of the compressed air drops. This is made possible by the evaporator coil's blower fan, which normally rotates the chilled water around the coil to cool back the refrigerant. Usually, a cycling compressed air dryer has a digital controller that reverses the flow of cold water in the coil. This allows the blower fan speed to be reduced. The blower fan speed reduction lowers the flow rate of cold water that passes through the coil. The cooler runtime is extended, and the idle time for the water to warm up is increased. The blower fan speed is reversed or changed whenever the compressed air temperature changes. This is how a cycling compressed air dryer saves energy while still effectively drying compressed air. Another common feature of a cycling refrigerated compressed air dryer is the blower fan operating and ambient temperature sensing. With this feature, the blower fan will run only when there is sufficient ambient temperature to achieve the required cooling.
• Non-Cycling Constant/Dryers ON: A non-cycling constant compressor air dryer does not have any adaptive feature that could let it conserve energy. Instead, it constantly uses power to refrigerate its evaporator coil. One advantage of a non-cycling constant dryer is the simplicity of its design. This allows for easy installation. Because there's not really much going on in the mechanism, maintenance and servicing are also easier to carry out. The constant running of the compressor means that the refrigerated compressed air dryer will provide consistent drying. Users can conveniently use the product when they need to. Nevertheless, non-cycling constant models use more energy than their cycling counterparts.

Specifications & Maintenance

The performance of refrigerated air dryers primarily depends on their specifications. Understanding the specifications is critical for matching the proper refrigerated dryer to the application's distinct compressed air demands and analyzing the expected operating expenses.

• Dryer capacity: Dryers with capacities of 50 to 5,000 SCFM are common. Higher capacities often correlate to larger physical dimensions and greater energy costs because they need more significant refrigeration equipment to chill more excellent volumes of coolant gas. The average refrigerated air dryer has a capacity of about 1,000 SCFM, and capacities can be as great as 5,000 SCFM or more for more giant, specialized models. Fittings that allow the compressed air supply line to connect to the dryer are often available in varying sizes.
• Pressure drop: A refrigerated compressed air dryer will generate a pressure drop of about 5.0 psi at a typical operating temperature. The bulk of the pressure loss is caused by the aftercooler and air-to-air heat exchangers, which contain significant air passage areas to maximize the cooling of the air. Higher pressure losses limit the use of dryers with a higher typical pressure loss within an air compression system.
• Separation mechanism: All refrigerated dryers use the same basic design, an evaporator-based refrigerator that cools and condenses the water vapor. However, the method for separating the condensed water is different. Up to 80 of the water is removed by an air separator upstream of the evaporator. A centrifuge uses high centrifugal forces to extract water after cooling. Refrigerated dryers typically achieve water separation through a mechanical valve that passes water into a drainage system or a manual valve for water separation.
• Energy efficiency: The amount of energy needed to operate the dryer can greatly influence the network's operating expenses. Different drying processes have different energy efficiencies. For example, the desiccant drying process generally has low energy efficiency due to the regenerative heating needed for this drying method.

Maintenance

A properly functioning refrigerated compressed air dryer is essential to the overall health of the compressed air system and connected tools and parts. Regular maintenance is vital to the dryer's performance and the entire air system's longevity and efficiency. Some daily, weekly, and monthly maintenance procedures should be performed to keep air dryers functioning well.

• Daily maintenance: Daily, operators should visually inspect the unit to look for any obvious signs of wear, failure, or damage, such as puddles, pooling water, or water mist around the unit. The water separator reservoir level should also be checked and drained if the water level exceeds the safe or fill level. If the cooling fan is running continuously, it may be malfunctioning, and the service manual should be reviewed, or a professional technician should be contacted. If LPG is used, make sure the fuel is full.
• Weekly maintenance: The separator reservoir level should be checked weekly and drained as instructed. The operating temperature should be recorded to ensure the unit operates within an acceptable temperature range. The fan's run time should be recorded to ensure it is functioning correctly and for the expected duration.
• Monthly maintenance: The monthly maintenance checks are critical for the dryer's well-being in monthly AC maintenance. Air filter cleaning or replacement as recommended and a compressor inspection and testing, including inspection of the refrig dryer refrigerant circuit

Scenarios of Refrigerated Compressed Air Dryer

Refrigerated compressed air dryers play an essential role in different types of industries applications that use compressed air. Below are some merits of using a refrigerated compressed air dryer.

• Industrial Manufacturing: In any industry manufacturing area, a refrigerated compressed air dryer can be used to remove moisture from the air. This allows a reliable source of dry air that can be used by different tools like spray guns, sandblasting equipment, and paint booths. Having a dry air supply helps to achieve clearer and greater quality of air that ensures effective surface coatings and a reduced level of equipment jams.
• Food and Beverage: In the food and beverage area, it's crucial to have a compressed air dryer installed. Doing so provides a protected level of dry air that is clean for use in food processing and packaging activities. This helps to prevent any problem that can be caused by excessive moisture on processing equipment to achieve hygiene standards and food safety compliance. It also helps to prevent contamination and product spoilage that is necessary for quality control.
• Electronics and Telecom: A refrigerated compressed air dryer can be used to protect delicate electronic and telecommunication components from oxidation and moisture damage. It does this by providing clean and dry air to the pick-and-place machines and soldering equipment during circuit board assemblies. Using a dry air supply protects electronic integrity and reliability of the final product.
• Pharmaceuticals: In the pharmaceutical industry, air quality must be well-managed to achieve the standards for aseptic manufacturing. A refrigerated compressed air dryer can be used to achieve this by removing moisture from the compressed air that is used in critical processing and packaging activities. Using this refrigerated dryer helps to minimize microbial growth, protect product purity, and achieve compliance with stringent regulatory standards.
• Construction and Workshops: In construction sites and workshops, a refrigerated compressed air dryer can be used to prevent tool freezes during welding, painting, and pneumatic tool operations activities. It can also be used to prevent condensate build-up and clogging in air lines. This is possible by providing dry compressed air for lubricated pneumatic tools and air-operated machinery.
• Automotive and Assembly: Automotive manufacturers often use a refrigerated compressed air dryer in their assembly line for spray painting and tool automation. The dry air produced by the refrigeration dryer helps to achieve smooth finishing in spray painting with no obstacles in paint guns.
• Textiles: The textile industry can use a refrigerated compressed air dryer in the spinning and weaving equipment. This will provide a moisture-free air supply needed to ensure reliable operation and minimize the risk of machine jams during work processes.

How to choose Refrigerated Compressed Air Dryers

Selecting the suitable refrigerated compressed air dryers for a specific application can make a significant difference in the final air quality, energy consumption, and system performance. The following tips will help customers choose the right refrigeration air dryer for their needs.

• Understand the specific requirements

  Users should first identify their compressed air system's specific requirements. Consider the factors, including the maximum allowable upstream temperature, the desired downstream pressure, the air flow rate, and the level of moisture removal required. Understanding these factors will help users select a dryer that meets their system's needs.

• Evaluate the drying performance

  Not all refrigerated air dryers offer the same level of performance. Users should look for dryers that can effectively remove moisture from the compressed air to the desired level. Pay attention to the dryer's dew point rating (expressed in degrees) - the lower the dew point, the drier the air.

• Check the energy efficiency

  Compressed air refrigeration dryers consume energy to cool the air and remove moisture. Users should select a dryer with high energy efficiency to minimize energy consumption and operating costs. Look for features such as fine-tuned cooling capacity, intelligent control systems, and low-pressure drop design that can help reduce energy consumption.

• Consider the design and build quality

  A refrigerated air dryer is often a critical component of a compressed air system, and its failure can have significant consequences. A well-designed refrigerated compressed air dryer built with quality materials can provide better system protection and longer service life.

• Think about service and support

  It is essential to consider the service and support options available after purchasing a refrigerated compressed air dryer. Select a supplier that offers prompt technical assistance, spare parts availability, and repair services. This ensures users can receive the necessary support to maintain their dryer's performance and reliability.

Refrigerated compressed air dryer FAQ

Q1 What is the lifespan of a refrigerated air dryer?

A1 The average lifespan for a refrigerated air dryer is 6-10 years, depending on the factors such as the quality of the equipment, frequency and quality of maintenance, operating environment, usage and operating hours, etc.

Q2 What is the biggest advantage of a refrigerated air dryer?

A2 The major advantage of a refrigerated air dryer is the ability to remove moisture from compressed air effectively. By cooling the compressed air to condense the moisture out, refrigerated air dryers help prevent water from entering downstream equipment and processes.

Q3 Does a refrigerated air dryer need maintenance?

A3 Like any other equipment, refrigerated air dryers do need maintenance. Regular maintenance helps ensure optimal performance and prolong the lifespan of the dryers. Neglecting maintenance could lead to a decline in drying efficiency, potential damage, and increased energy consumption.