|
Compressed air is used in industries for various applications in pneumatic tools, instruments and machines and in a variety of production processes. The consequences of using wet air causes rust and scale deposits in steel pipes, increases resistance in flow, malfunctioning of process control instruments, corrosion and damage to electromagnetic valves and pneumatic system, peeling and blistering effect on spray painted surface etc. Thus it will affect the quality of product and leads to excessive maintenance cost.
|
| Compressed system & Oil filter :- |
| |
Air from the compressor has excessive moisture and contaminants. The sketch below shows a typical Compressed air system to remove these damaging impurities and getting Clean Dry air. When compressed to
7Kg/cm2g the temperature of discharge air reaches around
140oC. The after cooler and Separator installed after the compressor will cool the air and remove 90% of moisture and oil. For instance, when the compressor takes in 100 NM3/hr of ambient air at
40oC and 50% relative humidity at 7Kg/cm2g, the after cooler will condense an average of 30 liters of water in 24 hours. If the outlet air temperature from the after cooler is
40oC, it still contains 8000-ppm of moisture. At
45o C compressed air contains 10,500 ppm, at
50oC, 13,500-ppm moisture that is removed by Air Dryer. Therefore, lower the temperature of air at dryer inlet, smaller would be the size of Air Drying Unit. |
| |
|
|
| Dew Point :- |
| "Dew point is the measurement of moisture in Air. It is the temperature at which moisture present in the Air starts condensing. Lower the Dew Point, more dry is the Air”. |
CHART OF DEW POINT |
Dew Point At Atmospheric pressure |
Moisture Contents by volume (ppm/ vol.) |
Zero |
6020 |
- 50
C |
3955 |
- 100
C |
2562 |
- 200
C |
1015 |
- 300
C |
374 |
- 400
C |
126 |
- 600
C |
10 |
- 800
C |
0.54 |
- 1000
C |
0.0138 |
|
| |
| |
| OIL FILTER :- |
Oil present in Compressed air is detrimental to the desiccant of Air Dyer. If not removed, it gets coated on the desiccant and reduces moisture adsorption capacity resulting in frequent replacement of desiccant. Therefore if your compressor is oil-lubricated type, an oil filter before the air dryer is essential. This oil filter has Activated Carbon, which removes oil from the air completely and thus enhances life of desiccant.
|
|
| |
