KA IMO 2021 6 V2.1

60 systemair
Bleed-off factor
With a given water quality, the bleed-off factor (f0) is determined by means of the water quality diagram.
If the water bleed-off factor, fo, exceeds 2, the application of a direct water system is recommended, or the water
quality should be improved.
Direct water system:
E = (V x 60 x 1.2 x (X2 - X1)) / 1000
O = f
o
x E
S = E + O
E - amount of absorbed water (l/min)
O - amount of bleed-off water (l/min)
S - total water consumption (l/min)
V-volumetricairowrate(m3/h)
1.2-standardairspecicmass(kg/m3)
X
2
-outletairhumidity(g/kg)
X
1
-inletairhumidity(g/kg)
f
o
- bleed-off factor
60 - conversion factor ((m3/s) to (m3/min))
1000 - conversion factor ((g/min) to (l/min))
Example calculation:
V = 2.8 m3/s
pH = 7.1
Calcium concentration
(Ca2+) = 100 mg/l (100 ppm)
Bicarbonate concentration
(HCO3) = 100 mg/l (100 ppm)
Inletairhumidity(x1)=2g/kg
Outletairhumidity(x2)=9g/kg
From the water quality diagram: (fo) = 0.3
E = (2.8 x 60 x 1.2 x (9 - 2)) / 1000 = 1.41 l/min
O = 0.3 x 1.41 = 0.42 l/min
S = 1.41 + 0.42 = 1.83 l/min
Commissioning
• Onthehumidiedairoutletside,providethehumidiersectionwithaservicespace300-300mminwidth.
• Upon installation, seal all the gaps to the casing.
• Connectthewatersupplyanddrainfromthehumidierwithasyphon.
Caution
Asregardsmicrobiologicalparameters,thellingsupplywatermustmeettherequirementsforpotable
water and the requirements of the applicable regulations.