Thermal Care Oiltherm RO, Руководство по эксплуатации, установке и обслуживанию

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poisonous, easy to handle, widely available, and
inexpensive in most industrialized areas.
When using water as a heat transfer fluid it is
important to keep it within certain chemistry limits to
avoid unwanted side effects. Water is a “universal
solvent” because it can dissolve many solid
substances and absorb gases. As a result, water can
cause the corrosion of metals used in a cooling
system. Often water is in an open system (exposed
to air) and when the water evaporates, the dissolved
minerals remain in the process fluid. When the
concentration exceeds the solubility of some
minerals, scale forms. The life giving properties of
water can also encourage biological growth that can
foul heat transfer surfaces.
To avoid the unwanted side effects associated with
water cooling, proper chemical treatment and
preventive maintenance is required for continuous
plant productivity.
Unwanted Side Effects of Improper Water Quality
•
Corrosion
•
Scale
•
Fouling
•
Biological Contamination
Cooling Water Chemistry Properties
•
Electrical Conductivity
•
pH
•
Alkalinity
•
Total Hardness
•
Dissolved gases
The complex nature of water chemistry requires a
specialist to evaluate and implement appropriate
sensing, measurement and treatment needed for
satisfactory performance and life. The
recommendations of the specialist may include
filtration, monitoring, treatment and control devices.
With the ever-changing regulations on water usage
and treatment chemicals, the information is usually
up-to-date when a specialist in the industry is
involved. The table below shows the list of water
characteristics and quality limitations.
Table 1 - Fill Water Chemistry Requirements
Water Characteristic Quality Limitation
Alkalinity (HCO
3
-
) 70-300 ppm
Aluminum (Al) Less than 0.2 ppm
Ammonium (NH
3
) Less than 2 ppm
Chlorides (Cl
-
) Less than 300 ppm
Electrical Conductivity 10-500µS/cm
Free (aggressive) Carbon Dioxide (CO
2
)† Less than 5 ppm
Free Chlorine(Cl
2
) Less than 1 PPM
HCO
3
- /SO
4
2- Greater than 1.0
Hydrogen Sulfide (H
2
S) Less than 0.05 ppm
Iron (Fe) Less than 0.2 ppm
Manganese (Mn) Less than 0.1 ppm
Nitrate (NO
3
) Less than 100 ppm
pH 7.5-9.0
Sulfate (SO
4
2- ) Less than 70 ppm
Total Hardness (dH)k 4.0-8.5
† Dissolved carbon dioxide calculation is from the pH and total
alkalinity values shown below or measured on the site using a test
kit. Dissolved Carbon Dioxide, PPM = TA x 2
[(6.3-pH)/0.3] where TA =
Total Alkalinity, PPM as CaCO
3
Table 2 – Recommend Glycol Solutions
Chilled Water Temperature Percent Glycol By Volume
50°F (10°C) Not required
45°F (7.2°C) 5 %
40°F (4.4°C) 10 %
35°F (1.7°C) 15 %
30°F (-1.1°C) 20 %
25°F (-3.9°C) 25 %
20°F (-6.7°C) 30 %
CAUTION: When your application requires the use of
glycol, use industrial grade glycol specifically
designed for heat transfer systems and equipment.
Never use glycol designed for automotive
applications. Automotive glycols typically have
additives engineered to benefit the materials and
conditions found in an automotive engine; however,
these additives can gel and foul heat exchange
surfaces and result in loss of performance or even
failure of the chiller. In addition, these additives can
react with the materials of the pump shaft seals
resulting in leaks or premature pump failures.
WARNING: Ethylene Glycol is flammable at higher
temperatures in a vapor state. Carefully handle this
material and keep away from open flames or other
possible ignition sources.