Knurr CoolAdd - 9. Appendix; 9.1 Quality requirements for water used in CoolAdd

CoolAdd
®
Manual / Bedienungsanleitung
CoolAdd 01.998.350.0 issue a page / Seite 24/59
9. Appendix
9.1 Quality requirements for water used in CoolAdd
To ensure the maximum service life of air-water heat exchangers, supplied cooling water must comply
with the VGB cooling water regulations (VGB-R 455 P). Cooling water must be soft enough to prevent
deposits, but must not be so soft that heat exchanger corrosion occurs.
The following table contains the most common impurities as well as the methods for removing them:
Water impurity Method o f removal
Mechanical pre-treatment (dp < 1 mm) Filtering the water
Excessive hardness Soften the water using ion exchange
Moderate content of mechanical impurities and hardness formers Addition of dispersing agents or stabilising
agents
Moderate content of chemical i mpurities Addition of passivat ion agents and
inhibitors
Biologica l impurities (bacte ria and algae) Addition of bio cides
It is recommended to achieve the following hydrological data as far as possible:
Hy drological data
pH values
7-8.5
Carbonate hardness
>3 <8 °dH
Free carbon dioxide
8 - 15 mg/dm3
Bound carbon dioxide
8 - 15 mg/dm3
Aggressive carbon dioxide
0mg/dm3
Sulphides
<10 mg/dm3
Oxygen
<50 mg/dm3
Chloride ions
< 250 mg/dm3
Sulphate ions
<10 mg/dm3
Nitrates and nitrides
< 7 mg/dm3
CSB
< 5 mg/dm3
Ammonia
< 5 mg/dm3
Iron
< 0.2 mg/dm3
Manganese
< 0.2 mg/dm3
Conductivity
< 2200 μS/cm
Solid evaporation residue
< 500 mg/dm3
Potassium permanganate consumption
< 25 mg/dm3
Suspended matter
< 3 mg/dm3
(Partial flow cleaning is recommended)
>3<15 mg/dm3
(Continuous cleaning)
> 15 mg/dm3