Water treatment of cooling circuits
The use of untreated or teilenthärtetem water as feed water for the operation of cooling water circuits, or air scrubbers usually leads to problems such as:
- Deposition of mineral substances (calcium deposits),
- Formation of biological slime deposits by bacteria and algae,
- Attack of the metallic materials due to corrosion, if the recycled water is not controlled by an automatic monitoring and control of quality, and by the conditioning with special chemicals.
In response to this problem, the GEWA designed water treatment plants. These are connected via a sub power line to the cooling water circulation or air scrubbers and continually monitor the water quality by means of the following components:
- Conductivity controlled to limit the salinity desalination device,
- Dispenser for a hardness stabilizer and corrosion inhibitor
- Dispenser for a biocide (time) or UV disinfection plant (air scrubbers)
Due to the evaporation of the water cycle of the accumulation in the water (dissolved salts will thicken). Through continuous measurement of conductivity, this process can be monitored and regulated. The conductivity reaches the set at the control unit of the desalination device set point, the blowdown valve is opened and derives a portion of the cycle of water in the canal. About Walda water top leads to a dilution of the water cycle and a decrease in conductivity. The built-in feed-water pulse water meter records the amount of feed water and are enforced control pulses to the metering pump inhibitor. This is then metered the required amount of inhibitor directly into the circulating water. As the dosage is proportional to the quantity of fresh water and thickening in the cooling tower by monitoring the total salt content remains constant, is always a sufficient and constant concentration of chemicals to ensure the cooling water. The capacity of the metering pump, the size and the pulse sequence (liter / stroke) must be matched to the size of the circulation and the quality of the added water werdenDas biocidal shock dosing schedule as regularly added to the biocidal dosing pump. It is controlled via the timer. Biocide by the uncontrolled growth of algae, fungi and slime bacteria is prevented.
Depending on the quality of the used feed water (city water or well water), additional measures described above, water treatment necessary, or even under consideration of economic factors may be advantageous. The crucial cost factor in the operation of heat exchangers, the consumption of water and wastewater. By optimizing the thickening of this factor can be positively influenced. A softening and grading of the feed water allows a rule, a substantial increase in the concentration figures. The use of-extended water from a reverse osmosis unit or a Entcarbonisierungsanlage allows the highest Eindickungsfaktoren and allows, to stop the feed water to an optimum between deposition tendency and corrosiveness
