ENVIRONMENTALLY FRIENDLY TECHNOLOGY SUPER ABSORPTION

Building table 19. Water quality standard values for cooling water and chilled water

Management of cooling water quality

Cooling water system Chilled water systemTendencyRecirculating type RecirculatingpH(25 Make-up waterOnce through(One way) typeMake-up waterCorrosiveScale formingbelow 20 ° CRecirculating ° C)Electricalconductivity 25 6.5 to 8.280 or less200 or less200 or less100 or less200 or less150 or less50 or less1.0 or less0.3 or lessNo detected1.0 or less0.3 or less4.0 or less60 to 7.0 6.0 to 8.030 or less50 or less50 or less50 or less70 or less50 or less30 or less0.3 or less0.1 or lessNo detected0.1 or less0.3 or less4.0 or less*** 7.0 to 8.030 or less50 or less50 or less50 or less70 or less50 or less30 or less1.0 or less1.0 or lessNo detected0.3 or less0.25 or less4.0 or less*** 7.0 to 8.030 or less50 or less50 or less50 or less70 or less50 or less30 or less1.0 or less1.0 or lessNo detected0.1 or less0.3 or less4.0 or less*** 7.0 to 8.030 or less30 or less30 or less50 or less70 or less50 or less30 or less1.0 or less1.0 or lessNo detected0.1 or less0.1 or less4.0 or less*** 7.0 to 8.030 or less30 or less30 or less50 or less70 or less50 or less30 or less0.3 or less0.1 or lessNo detected0.1 or less0.3 or less4.0 or less*** 6.8 to 8.040 or less50 or less50 or less50 or less70 or less50 or less 30 or less1.0 or less1.0 or less

Quality control of cooling water

° CChloride ionSulfate ionAcid consumptionpH 4.8 Total hardnessCalcium hardnessIonic silicaIronCopperSulfide ionAmmonium ionResidual chlorineFree carbon dioxideRyzner stabilityindex (ms / m)(mgCI- / I)(mgSO

The cooling water of an open-type recycling cooling tower lowers tem-perature of the cooling water using vaporized latent-heat, and is reused.At this time, the water is evaporated and dissolved salts. Hardness mate-rials sulfate ion, etc. in the water will increase. Namely, condensation phenomena of such materials occurs in the water, and water quality will gradually be degraded. As the water and air always come in contact witheach other in the cooling tower, sulfurous acid gas, dust, sand and etc. inthe atmosphere will mix into the water, further degrading the water qual- ity. In the cooling water system, problems with water are caused by thesefactors. Typical problems are corrosion, scales and slimes.

42 - / I)(mgCaCO
3 / I)(mgCaCO
3 / I)(mgCaCO

Water treatment

3 / I)(mgSiO
2 / I)(mgFe / I)(mgCu / I)(mgS

As with any system utilizing an open or closed loop water circuit, the useof water treatment is a necessity to insure long life and efficient operationof the entire system.Impurities in the water such as scale, dirt, bacteria, etc. will adhere to heat transfer surfaces causing a loss of efficiency, higher operating costs,and a potential for mechanical damage.Proper and continued water treatment by a reputable water treatment company should be continued for the life of the equipment. Water treat- ment specialists can also help determine the necessary time intervals for tube inspections and/or tube brushing/cleaning. Added attention must be given on retrofit jobs when the existing piping isreused. Air infiltration into the piping will cause a rapid build-up of rustand corrosion inside the piping. Scale and debris may break loose from the inside walls of the piping during retrofit operations. The use of waterstrainers and water treatment will be necessary to remove the larger par-ticles from the system and keep the smaller particles in suspension.

2 - / I)(mgNH No detected1.0 or less0.3 or less4.0 or less*** 6.8 to 8.040 or less50 or less50 or less50 or less70 or less50 or less30 or less1.0 or less1.0 or lessNo detected1.0 or less0.3 or less4.0 or less*** 6.8 to 8.030 or less50 or less50 or less50 or less70 or less50 or less30 or less0.3 or less0.1 or lessNo detected0.1 or less0.3 or less4.0 or less***
4 + / I)(mgCI / I)(mgCO
2 / )(RSI)
Reference itemsStandard items

Figure 69. Temperature control of cooling water

Table 20. Water quality standard values for mid-range temperature water

Mid-range temperature (20-90 ° C) water system TendencyLower level (20 to 60 ° C)Higher level (60 to 90 ° C)RecirculatingpH(25 ° C)Electrical conductivity 25 ° CChloride ionSulfate ionAcid consumptionpH 4.8Total hardnessCalcium hardnessIonic silicaIron CopperSulfide ionAmmonium ionResidual chlorineFree carbondioxideRyzner stability index (ms / m)(mgCI- / I)(mgSO
42 - / I)(mgCaCO
3 / I)(mgCaCO
3 / I)(mgCaCO
3 / I)(mgSiO
2 / I)(mgFe / I)(mgCu / I)(mgS
2 - / I)(mgNH

Water supplyChemicals adding pump Chemicals tankTo building chiller From chiller CoolingWater pump MV Cooling water thermostatfor three-way control valve Automatic three way control valve

4 + / I)(mgCI / I)(mgCO
Blow

Notes :

2 / )(RSI) Make-up waterRecirculatingMake-up waterCorrosiveScale forming

K indicates factors affecting the corrosive or scale-forming tendencies.3)When temperature is high (above 40

Reference itemsStandard items

1)The nomenclature of items, definition of terms and units shall comply with the JIS K 0101. 2)The mark ° C), corrosiveness generally increases.Especially, when the iron/steel surface has no protective film and directly contacts water, it is desirable to adequately take countermeasures against corrosion, such as the addition of acorrosion inhibitor and deaeration treatment.4)As for the cooling water system using a closed type cooling tower, the water quality standard forthe mid-range temperature water system shall be applied to the closed circuit recirculating/sprinklingwater and its make-up water, while the water quality standard for the recirculating cooling watersystem shall be applied to the sprinkling water and its make-up water, respectively.5)City water, industrial water and ground water shall be used as source water, and demineralized waterreclaimed water, softened water, etc. shall be excluded.6)The 15 items listed above show typical factors of corrosion and scale problems.

Cooling water thermostatfor cooling tower building fan Constant flowblow valveCooling tower

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