ThermoKey Wet Fin Systems Manuel Technique page 9

ThermoKey Heat Exchange Solutions
TC 9. Water Quality
The "Wet Fin System" is designed for a maximum annual utilization period of 1,000 hours
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The spray water must comply with the requirements of Council Directive 98/83 / EC on the quality of water for human
§ §
consumption.
Furthermore, the following limits are defined:
Position Parameter Unit
1 El. conductivity µS/cm
2 pH -value
3 Total hardness °dH
4 Chloride mg/l
5 Sulfate mg/l
6
Nitrate mg/l
7 Iron dissolved mg/l
8
Silicon mg/l
9 Colony forming units KBE/ml (22°/37°C)
10 Legionella CFU/ 100 ml
SAC 254 (spectral
11 m -1
absorption coefficient)*
12 Water pressure bar
* Mandatory when using a UV lamp
TC 9.1 MICROBIOLOGICAL CONTROL OF THE SPRAY WATER
To control the microbiological proliferation of the intake spray water, an UV lamp can be installed into the feed water
line. Therefor the spray water must have a SAC 254 (spectral absorption coefficient) of < 20 m-1 and the lamp must have
a radiation power of ≥ 400 J/m 2 .
Monitoring the quality of the spray water:
The quality of the spray water must be controlled online by an electrical conductivity probe.
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The WFS system is delivered without such a system. Please contact your water treatment company to install one.
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TC 9.2 MAINTENANCE
It should be ensured by installer that the chemicals added in order to respond to these parameters, do not cause any
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stress corrosion on the materials used in the unit or indeed damage them.
The water values must be tested during the commissioning procedure by a testing institute and thereafter every six
§ §
months. The results must be documented and recorded.
If the water values change, the appropriate countermeasures must be taken without delay and spraying is prohibited in
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15 MT TC R WFS EN 03 2018
Limits
< 1.500
6,5 – 8,2
3,5 – 4,0
< 50
< 90
< 50
< 0,1
< 20
< 100/ml
< 100
< 20
1 - 6
this case.
If the notification times are not observed, ThermoKey is entitled to refuse to carry out work under the warranty.
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For any other information please examine the Installation and Maintenance Manual of the remote air-cooled unit on
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which the adiabatic system is installed and Adiabatic Manual.
TC 9.3 NOTES
Hardness conversion
1 °dH (°dH) German hardness: Ca and/or Mg salt, which is equivalent to 1 °dH=17.85 mg/l calcium carbonate
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(CaCO3) or 1 °dH=10 mg/l calcium oxide (CaO), is dissolved in 1 liter of water.
German Degrees (°dH) =1,78 X French Degree (°F)=1,24 X English Degree (°E).
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Electrical Conductivity
The treated water must be balanced: to prevent spontaneous corrosion and/or fouling the Langelier Saturation Index
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( LSI ) and Ryznar Stability Index ( RI ) should be in the following range: -1<=LSI<=+ 1 ; 5.5<=RI<=6.6.
The cooling water must be in any case conditioned by the addition of suitable inhibitors of corrosion/fouling . With
appropriate conditioning is possible that they are acceptable even waters with characteristics that do not meet the ideal
characteristics indicated above.
TC 10. Maintenance
TC 10.1 NOZZLE MAINTENANCE
Lifetime of materials and efficiency of working can only be guaranteed, if the sprayer is inspected on a regular basis
(recommended 5hours after the first use and then every 100 hours).
Common factors of spray nozzles problems:
Erosion/wear: gradual removal of metal causes the nozzle orifice and internal flow passages to enlarge and/or become
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distorted. As a result, flow is usually increased, pressure may decrease, the spray pattern becomes irregular, and drops
become larger.
Clogging: unwanted dirt or other contaminants can block the inside of the orifice. Flow is restricted and spray pattern
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uniformity disturbed.
Caking: over spraying, misting, or chemical buildup of material on the inside or outer edges of the orifice from
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evaporation of liquid can leave a layer of dried solids and obstruct the orifice or internal flow passages.
Temperature damage: heat may have an adverse effect on nozzle materials not intended for high-temperature
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applications.
Improper reassembly: misaligned gaskets or other re-positioning problems can result in leakage as well as poor spray
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performance.
Accidental damage: scratching through the use of improper tools during installation or cleaning can cause inadvertent
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harm to an orifice.
MT TC R WFS EN 03 2018
Technical Manual TC Instruction and technical data
16