NAILI supply professional and honest service.
We often think of water as being essential to life, but it can be very detrimental in manufacturing. In an air compressor set up, water vapor becomes concentrated during the process of air compression. If allowed to build up, this excessive water can lead to a variety of operational problems and production complications.
An industrial compressed air dryer is used to separate water vapor from process air and cool it, so the air can be compressed efficiently. This step is necessary to prevent such production failures as freezing outdoor air lines, dangerous corrosion in piping and equipment, and malfunctioning of pneumatic process control instruments.
JHFOSTER distributes a variety of compressed air dryers to keep production running smoothly. Our line includes regenerative, breathing air system, membrane, and refrigerated cycling and non-cycling. Air dryers are essential to keep your air compressor set up free of moisture, and prevent rust build-up. This article looks at the different types of compressed air dryers, and discusses some possible applications for each.
Refrigerated air dryers are typically used in industrial applications because they are easy to maintain, relatively low-cost, and have few special requirements. Similar to a home refrigerator or air-conditioner, the industrial refrigerated air dryer works in the following way:
Refrigerated air dryers are typically best used for general plant operations, as opposed to critical processes that may require extremely dry air.
Variable Speed Refrigerated Air Dryer from QuincyIn these dryers a desiccant is used to adsorb water vapor in the air stream. Here the moisture adheres to the desiccant itself, and collects in the pores of the desiccant beads. Because they are capable of achieving a very low dew point, these dryers are perfect for use in colder climates or for industries which require super dry air.
Although a single tower set-up is possible, desiccant-type air dryers usually have a twin tower construction. One tower is used to dry the air, while spent desiccant is regenerated in the second tower. Moisture is driven off by a dry air purge, heat, or some combination of both.
The dry air process utilizes purge air to expel moisture, which can fall in a range of up to 18% of the total air flow. The dew point rating in the desiccant dryer is about -40°F, but it can be driven as low as -100°F. The heated process has a heater in the circuit, with similar dew points. Valves are used to divert about 8% of the air which is leaving the drying tower and send it through the heater. The hot and dry air is then passed through the regenerating tower, with captured moisture discharged to the outside.
Cost is an important deciding factor in choosing a desiccant-type air dryer. A heated dryer may use about half of the compressed air for regeneration, but they do require a lot of electricity. On the other hand, the heatless dryer offers great energy savings. With these dryers, you also need to remember the cost to periodically replace the desiccant bed, usually every 3-5 years.
Regenerative Desiccant Dryer from ZEKSA membrane air dryer incorporates a specially designed, permeable membrane which allows water vapor to pass through it. A high purge air loss is required to achieve the required pressure points. This process has a low installation and operating cost, and involves no moving parts, but the membrane can become fouled by oil and other contaminants. This type of dryer is particularly suited to low-volume operations, outdoor installations or hazardous environments.
Choosing the proper air dryer for your air compressor setup can be a complicated process, but it is not one you have to experience alone. From start to finish, the compressed air specialists at JHFOSTER have the knowledge and experience to help you easily navigate the journey towards maximizing the efficiency of your air compressor system. We also maintain the JHFOSTER Compressed Air Library, which is full of free compressed air resources.
Want more information on air dryer machine? Feel free to contact us.
Headquartered in Eagan, Minnesota, JHFOSTER is a leading distributor and service provider of automation and compressed air systems. We are committed to providing successful solutions that exceed production demands, reduce costs, and increase overall efficiencies. Contact us online, request a quote, or call 855-688- for more information on air dryers.
&#;In several types of automated industries, compressed air is used for various purposes such as spray painting or pneumatic tools (compressed air equipment). A common problem in compressed air systems is the condensation of humidity. It appears along distribution pipes, blocking filters and machinery, and causes malfunction of the system. The water can cause corrosion and considerable damage to the equipment using the air. The condensation is due to the water vapor in the compressed air. This vapor is cooled along the pipes, and thus transformed to water droplets.
To avoid water condensation in a pneumatic system, an air dryer can be installed in the system (see Figure 10.21). The basic function of the air dryer is to remove moisture from the air by cooling it with a refrigerant. Thus, the water vapor is condensed, and the air can be compressed. The result is dry compressed air, which can be used in compressed air equipment without causing any damage.
In a pneumatic system, the air leaving the compressor (point 1 in Figure 10.21) contains a significant amount of water. In the after-cooler (2), up to 70% of the moisture can be removed. After the separator (3), the compressed air is still saturated with moisture. The air is then stored in a receiver (4), which can be installed before or after the air dryer (6). The goal of the air dryer is to eliminate the remaining 30% of the moisture.
The system design with the air dryer after the receiver, as shown in Figure 10.21, is recommended when the compressor operates intermittently and the air demand is not more than the maximum compressor capacity. If the air demand can exceed the maximum capacity of the compressor, the installation of the air dryer before the receiver is recommended. The cooling conditions in a pneumatic system can be demonstrated by monitoring the pressure, temperature and humidity during the compressing and cooling stages, as shown in Figure 10.22.
In the compressor, free air at 20°C, 1 bar and 50% relative humidity is compressed to typically 7 bar g. During compression, the temperature increases (from 20 to 80 0C), and the relative humidity decreases. Because no vapor condensation takes place, the absolute humidity is constant. When the air is cooled in the after-cooler, the relative humidity increases to 100%. After the "dew point" (where the air is saturated), the vapor condenses with a reduced absolute humidity as a result. Most of the remaining humidity is condensed in the air dryer. During this condensing process, the air is in saturated conditions, which correspond to a relative humidity of 100%. When re-heating the air in the air dryer, the relative humidity will again decrease, as shown in Figure 10.22.
SWEP air dryers are an ingenious version of the compact brazed heat exchanger. They transform the moist warm air from an ordinary air compressor to dry air at ambient temperature. Figure 10.23 explains the flow pattern, and shows the port locations.
The warm, moist air from the compressor (point A in Figure 10.23) is pre-cooled in an air-to-air heat exchanger (the air from the compressor being cooled by the leaving dry air). Then the moist air enters the second chamber of the brazed plate heat exchanger where it is further cooled by the refrigerant from the refrigerant compression cycle (E-F). The condensate is then separated from the air stream at point (B). The cold dry air then makes a second pass through the air-to-air heat exchanger to be reheated before leaving the dryer.
The SWEP brazed plate heat exchanger air dryer offers a very compact and cost-effective alternative to other heat exchange solutions by combining high heat transfer with stable performance and creative engineering.
The B12 has been specifically developed as a heat exchanger for air dryers. The majority of the conventional brazed plate heat exchanger models create relatively high pressure-drop in air dryer applications. If the pressure drop in the heat exchanger is too high, it will reduce the overall performance of the pneumatic system, i.e. the system will not be able to deliver the required pressure to the pneumatic tools. The B12, however, has a low pressuredrop.
It can handle asymmetrical flows and can be used as a combined air-to-air and refrigerant-to-air heat exchanger.
<< back | next&#;&#;&#;&#;&#;&#;&#; >>
Contact us to discuss your requirements of portable tank vane compressor. Our experienced sales team can help you identify the options that best suit your needs.