Water Quality Requirement - Pfannenberg PWI 6302C/ 115 V Betriebsanleitung

GB
3.4.5

Water quality requirement

 Observe the VGB cooling water guidelines for safe operation of the air/ water heat exchangers
(VGB-R 455P).
Cooling water must fulfill the following requirements:
 It may not cause any mineral scale deposits or loose discharges.
 It must be of a low degree of hardness, especially having a low carbon hardness (especially for recooling)
 In the case of recooling, the saline content may not increase excessively due to the evaporation of large
amounts of water.
 In the case of substances dissolving with an increasing concentration, the electric conductivity of the water
increases and the water becomes more corrosive.
 The degree of softness of the water must be within a range in which it does not negatively affect any materials.
 Fresh water should be added to the cooling water at regular intervals and part of the enriched water is to be
removed.
 Water containing gypsum is not suited for cooling purposes. It causes the formation of boiler scale, which is
difficult to remove.
 Cooling water must be free of iron and manganese, because deposits result in blocked pipes.
 Organic substances (e.g. Mud discharge or microbiological loads) may only be present in very small quantities.
The most frequent contamination and most useful procedure for its removal are:
Type of contamination
Mechanical contamination
Comparatively high degree of hardness
Moderate content of mechanical impurities and hardeners
Moderate content of chemical impurities
Biological impurities (e.g. biofilms and algae)
The quality of the additional or system water used must agree with the hydrological data listed as follows:
Hydrological data
pH value
Carboxylic acid
free carbonic acid
affiliated carbonic acid
aggressive carbonic acid
Sulfides
Oxygen
Chloride ions
Sulfate ions
Nitrates and nitrites
COD
Ammoniac
Iron
Manganese
Conductivity
Evaporation residue
Potassium permanganate consumption
Suspended matter
Operating manual PWS and PWI 6302 C 086100048 © Pfannenberg GmbH
Version: Standard
7 - 8.5
°dH >3 <8
mg/dm³ 8 - 15
mg/dm³ 8 - 15
mg/dm³
free
mg/dm³ < 10
mg/dm³ < 50
mg/dm³ < 250
mg/dm³ < 10
mg/dm³ < 7
mg/dm³ < 5
mg/dm³ < 0.2
mg/dm³ < 0.2
S/cm
< 2200
mg/dm³ < 500
mg/dm³ < 25
mg/dm³ > 3 < 15 partial current cleaning recommended
> 15 continuous cleaning recommended
Procedure for removal
Filter water with:
 sieve filter, gravel filter, cartridge filter or
precoat filter
Soften water through ion exchange
Inoculate water with stabilizers or
dispersants
Inoculate water with passivators and/or
inhibitors
Inoculate water with biocides
Device version: VA
0
< 3
6 - 9
1 - 12
1 - 100
free
0 - 400
free
< 10
< 200
< 500
< 100
< 40
< 20
free
free
< 4000
< 2000
< 40
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