Air Dryers
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Air Dryers
Flow Range
We offer air dryers ranging from flows as low as 1 nm3/hr to very high flows up to 10,000 nm3/hr.
Dew Point
Dew point depends on the type of air dryer and we can offer dryers delivering dew point as low as (-) 80°C.
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TYPES OF AIR DRYERS
REFRIGERATED
A refrigerated air dryer is the most commonly used type of compressed air dryer / Gas Dryer for most plant applications for the drying of plant air and other utility gases like Seal gas, hydrogen gas for generator cooling, nitrogen Gas drying etc. where a dew point of +2°C at line pressure i.e. (-)22°C at atmospheric pressure is an acceptable norm.
HEATLESS
Two vessels filled with desiccant are provided in our heatless dryer design. These towers cycle automatically, producing Dry air continuously. Wet air enters the bottom of one vessel and passes upwards through the desiccant bed where the moisture is adsorbed. The dry air comes out from the top. A small portion of Dry air is passed downward through the desiccant bed in the second vessel, which is under re-generation. Moisture laden purge air is then vented out to atmosphere. The purge loss is around 7.5% of the total air flow. At preset interval, the vessels changeover automatically, and Dry air is available continuously, without any surges.
HEAT REACTIVATED
Heat Reactivated dryers are used when one needs compressed air of very low Dew point of (-)60°C or (-)80°C. In this design, the desiccant is regenerated at higher temperature, along with small quantity of Dry air purge. Due to purging with Dry air and thermal regeneration, residual moisture loading on desiccant becomes low and this gives very low Dew points.
HEAT OF COMPRESSION (HOC)
Our Hydrogen generators deliver very dry gas, with dew point as low as (-) 65°C. We also offer measuring instruments for online detection of gas dryness.
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DRY AIR – USEFUL INFORMATION
DEW POINT
All atmospheric air contains some water vapor, which will begin to condense into liquid water in the compressed air system when the air cools past the saturation point, i.e., the point where it can hold no more water vapor. The temperature at which this happens is known as the dew point. This dew point helps in determining how much compressed air drying is needed.
All atmospheric air contains some water vapor, which will begin to condense into liquid water in the compressed air system when the air cools past the saturation point, i.e., the point where it can hold no more water vapor. The temperature at which this happens is known as the dew point. This dew point helps in determining how much compressed air drying is needed.
| DEW POINT AT ATMOSPHERIC PRESSURE | MOISTURE CONTENT |
|---|---|
| 0°C | 3800 ppm |
| (-)5°C | 2500ppm |
| (-)10°C | 1600ppm |
| (-)20°C | 685 ppm |
| (-)30°C | 234 ppm |
| (-)40°C | 80 ppm |
| (-)60°C | 6.5 ppm |
| (-)80°C | 0.3 ppm |
MOISTURE IS NOT DESIRABLE
Compressed air is used as instrument air in most manufacturing plants and moisture in compressed air causes problems in the operation of pneumatic systems, solenoid valves and air motors. This can adversely affect the process or product being manufactured.
MOISTURE RELATED PROBLEMS
- Moisture is the leading cause of rust and increased wear of moving parts in production equipment as it washes away lubrication
- Where compressed air is used in painting, moisture can adversely affect the color, adherence, and finish of paint applied by compressed air
- Hampers functioning of process industries where many operations are dependent upon the proper functioning of pneumatic controls. The malfunctioning of these controls due to rust, scale, and clogged orifices can result in damage to product or in costly shutdowns
- May lead to corrosion of air or gas operated instruments, giving false readings, interrupting or shutting down plant processes.