15
1
/
2
˝
10. Notes on discharge
of condensate
A drain hose must be fitted to the
1
/
2
˝ flanged
socket protruding from the unit, to discharge any
condensate water accumulating.
For
SK 3219.100 / SK 3249.xxx
connect drain
hoses with elbow sockets (do not kink!) and direct
immediately downwards to avoid reflux and over-
flow of the condensate into the inside of the unit.
Fig. 10.1
Condensate discharge
SK 3219.100 / SK 3249.xxx
In order to ensure the safe discharge of conden-
sate, the following points must be observed:
●
Discharge hose must be routed free from kinks!
●
Do not reduce the hose cross-section!
●
Always install the drainage hose with a
downward slope!
In order to prevent increased development of con-
densate and also in the interest of energy savings,
the cooling water temperature should be matched
to the required cooling output (see performance
diagrams).
11. Safety instructions
●
When installing the device, the condensate
discharge must be routed out of the enclosure!
●
In order to avoid frost damage, the minimum
permissible water temperature of +1°C must
not be undercut at any point in the water cycle!
●
It is essential to obtain the manufacturer’s
permission before adding anti-freeze!
●
During storage and transportation below
freezing point, the water cycle should be
drained completely using compressed air!
●
Only set the thermostat as low as is strictly
necessary, because of undercutting the dew
point with a falling water inlet temperature
(condensation)!
●
It is very important that the enclosure is sealed
on all sides (IP 54), particularly the cable entry
(condensation)!
12. Notes on water quality
For safe operation of the equipment, it is essential
to observe the VBG guidelines on cooling water
(VGB R 455 P).
Cooling water must not contain any limescale
deposits or loose debris; in other words, it should
have a low level of hardness, particularly a low
level of carbon hardness. For recooling within the
plant, the carbon hardness should not be too
high. On the other hand, however, the water
should not be so soft that it attacks the operating
materials. When recooling the cooling water, the
salt content should not be allowed to increase
excessively due to the evaporation of large
quantities of water, since electrical conductivity
increases as the concentration of dissolved sub-
stances rises, and the water thereby becomes
more corrosive. For this reason, not only is it
always necessary to add a corresponding quan-
tity of fresh water, but also to remove part of the
enriched water.
Gypsiferous water is unsuitable for cooling pur-
poses because it has a tendency to form boiler
scale, which is particularly difficult to remove.
Furthermore, cooling water should be free from
iron and manganese, because otherwise de-
posits may occur which settle in the pipes and
block them. At best, organic substances should
only be present in small quantities, because
otherwise sludge deposits and microbiological
contamination may occur.
12.1 Preparation and maintenance
of the water in recooling systems
Depending on the type of installation to be
cooled, certain requirements are placed on the
cooling water with respect to purity. According
to the level of contamination and the size and
design of the recooling systems, a suitable
process is used to prepare and/or maintain the
water. The most common types of contamination
and most frequently used techniques to elimin-
ate them in industrial cooling are:
Contamination of the water
Procedure
Mechanical contamination
Filtering of water via
– Mesh filter
– Gravel filter
– Cartridge filter
– Precoated filter
Excessive hardness
Water softening via ion exchange
Moderate content of mechanical contaminants
and hardeners
Addition of stabilisers and/or dispersing
agents to the water
Moderate content of chemical contaminants
Addition of passifiers and/or inhibitors
to the water
Biological contaminants, slime bacteria and algae
Addition of biocides to the water
In order to ensure correct operation of a recooling
system which is operated with water on at least
one side, the properties of the added or system
Hydrological data
SK 3212.xxx / SK 3247.000 /
SK 3219.100 / SK 3249.100 /
SK 3214.100 / SK 3215.100 /
SK 3216.xxx / SK 3217.100 /
SK 3218.100
SK 3218.104
1)
SK 3249.104
1)
pH value
7 – 8.5
6 – 9
Carbonate hardness
> 3 < 8 °dH
1 – 12 °dH
Free carbon dioxide
8 – 15
mg/dm
3
1 – 100 mg/dm
3
Accompanying carbonic acid
8 – 15
mg/dm
3
free
Aggressive carbonic acid
0 mg/dm
3
0 – 400 mg/dm
3
Sulphides
free
free
Oxygen
< 10 mg/dm
3
< 10 mg/dm
3
Chloride ions
<
50 mg/dm
3
< 200 mg/dm
3
Sulphate ions
< 250 mg/dm
3
< 500 mg/dm
3
Nitrates and nitrites
<
10 mg/dm
3
< 100 mg/dm
3
COD
< 7
mg/dm
3
< 40 mg/dm
3
Ammonia
< 5
mg/dm
3
< 20 mg/dm
3
Iron
< 0.2 mg/dm
3
free
Manganese
< 0.2 mg/dm
3
free
Conductivity
< 2200 μS/cm
< 4000 μS/cm
Residue on evaporation
< 500 mg/dm
3
< 2000 mg/dm
3
Potassium permanganate consumption
< 25 mg/dm
3
< 40 mg/dm
3
Suspended matter
< 3
mg/dm
3
> 3 < 15 mg/dm
3
part current purification recommended
> 15 mg/dm
3
continuous purification recommended
water used should not deviate substantially
from the following list of hydrological data:
1)
The complete absence of corrosion under experimental conditions suggests that solutions with a
significantly higher salt content and greater corrosion potential (such as seawater) may still be
tolerated.
13. Spares list
(see page 28)
Summary of Contents for SK 3214.100
Page 22: ......
