Why you should buy the correct air dryer for your application.
How do you select the correct Air Dryer?
The air dryer must be sized correctly. If the air dryer is too small, you may flood the dryer and water moisture will still go through to your application. You can install an energy-efficient air dryer for one application in your factory or you can install it to dry all the compressed air being used in the factory.
If you size it for the one application, you must know the air consumption of this application. Go to Tools on this web site and calculate the air consumption (liter/min). If you want to dry all the compressed air of the factory, you must know the air compressor’s output. Go to Tools on this web site and calculate the air delivery of the compressor(s). Airpower can calculate it from the total compressor kW.
All dryers must have a pre-filter with an automatic drain. The water drained before the compressed air enters the air dryer reduces the load on the dryer. Air Dryers, such as membrane air dryers, are designed to have a maximum air inlet temperature of 40 °C. If you can keep your hand indefinitely on the inlet pipe, the temperature is fine. If not, you will need an aftercooler between your compressor and your dryer.
Refrigerated air dryers cool the compressed air down to 4°C. It filters the air under pressure at 4°C. The dew point is then 4°C under pressure. Refrigerated air dryers are limited to 4°C, because lower than 4°C, water starts to freeze in your system and blocks the flow.
The after filter is just a safety filter to take out the last bit of impurities, oil, or odors. With a refrigerated air dryer, you can get an ISO 8573-1 Class 1:4:1. The first 1 is for the particle size let through, the 4 is for the dew point and the last 1 is for the oil carryover.
If you need a dew point under the pressure of less than 4°C, you must select a desiccant dryer, also known as a heatless dryer. With a desiccant dryer, you can reach a dew point of -70°C. Desiccant dryers also use a pre and after the filter. You can reach an ISO Class 1:1:1 with a desiccant dryer.
Desiccant air dryers work with desiccant crystals. These crystals always adapt to their environment. If the environment is wet, it absorbs moisture, to become wet. If the environment is dry, it gives moisture off and becomes dry.
The desiccant dryer has two chambers. One under pressure and drying the compressed air. The other chamber is purging with approximately 15% of dry air, from the first chamber. When the second chamber is dry, it gets pressurized and starts to dry the air while the first chamber is getting purged again.
Refrigerated air dryers from 750 liters/min up to 6500 liter/min ex-stock. Larger ex overseas. Dew point 4°C under pressure. Automatic drain pre and manual drain after filters.
Screw compressors have no valves or other mechanical forces to cause imbalances unlike piston compressors.
Airpower keeps universal spare parts for compressors. Pressure switches, non return valves and safety valves are universal to all compressors. Bottom entry filters/ regulators, electric motors and starters can be used for many makes of compressors.