Air CompressorInstallation : Technical Data
Drain
Why is the power weak in summer? (Temperature increase, occurrence of drain)
A compressor generates heat, it also makes water.
Air contains moisture. The maximum content of the moisture in air is determined by temperature and pressure and it is called the saturated moisture amount (or the saturated moisture pressure if expressed by the partial pressure of the moisture). The saturated moisture amount increases as the temperature increases, and decreases as the pressure increases. This is the reason that the moisture condenses when air is compressed (called condensed water), and the condensed water grows as the compressed air is cooled. How much condensed water is generated when operating a compressor? The answer - the amount of condensed water generated is almost proportional to the amount of air taken in.
Examples of the calculation
If 10m3/min air is compressed to 7kgf/cm2.
(1) In summer
Temperature of intake air 30ºC
If the humidity of the intake air is 80%,
The water content in the intake air is 243cc/min.
| 30.4(g/m3) × | 80 100 |
× 10(m3/min) = 243(g/min) |
The water content in the intake air which is compressed to 7kgf/cm2 becomes 38cc/min, if the temperature at the compressor outlet is 30ºC.
| 30.4(g/m3) × | 1 8 |
(compression ratio) × 10(m3/min) = 38(g/min) |
The amount of the condensed water is 243 - 38 = 205cc/min
(2) Autumn
If The temperature of intake air is 20ºC
The humidity of intake air is 60%,
The amount of the condensed water in the intake air is 82.2cc/min, if the outlet temperature is 20ºC,Or 92cc/min, if the outlet temperature is 10ºC.
(3) Winter
If the temperature of the intake air is 10ºC and
The humidity of the intake air is 50%,
The amount of the condensed water in the intake air is 35.2cc/min, if the outlet temperature is 10, or42.1cc/min, if the outlet temperature is 0ºC.
The drain water generated throughout a year blocks the lubrication of the machine, prompts the deterioration of the lubricant, causes the corrosion of the air pressure system, and finally disables the compressor from working in a safe way. Therefore, it must be strictly controlled.
| Temperature ( ºC ) |
Saturated moisture amount (g/m3) |
Saturated moisture pressure (mmHg) |
|---|---|---|
| 0 | 4.9 | 4.58 |
| 5 | 6.8 | 6.54 |
| 10 | 9.4 | 9.21 |
| 15 | 12.9 | 12.79 |
| 20 | 17.3 | 17.54 |
| 25 | 23.0 | 23.76 |
| 30 | 30.4 | 31.82 |
| 35 | 39.6 | 42.18 |
| 40 | 52.0 | 55.32 |
| 45 | 65.0 | 71.88 |
| 50 | 83.0 | 92.50 |
| 55 | 104.0 | 118.00 |
| 60 | 132.0. | 149.50 |
| | | | | | |
| 100 | 597.0 | 760.0 |
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