Advantage BG-N4 Series, Инструкция по эксплуатации

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BG-N4 Glycol Chiller
Page: 63
ADVANTAGE ENGINEERING, INC.
525 East Stop 18 Road Greenwood, Indiana 46142
317-887-0729 Fax: 317-881-1277
Service Department Fax: 317-885-8683
Email: service@AdvantageEngineering.com
8.2 INHIBITED PROPYLENE GLYCOL
A. To operate liquid chillers below 48°F, it is necessary to add inhibited propylene glycol
to the circulating system to lower the freeze point and prevent damage to the cooling
system. Inhibited propylene glycol contains corrosion inhibitors which are compatible with
most industrial heat transfer surfaces. Inhibited propylene glycol is manufactured by:
• Dow Chemical - “DowFrost” (1-800-258-2436)
• Monsanto “Therminol FS” (1-800-459-2665)
• Advantage Engineering “Thermofluid” (1-317-887-0729)
• Chempoint (distributor) 800-485-9569
B. Automotive anti-freeze must never be used in industrial heat transfer applications.
Automotive anti-freeze contains silicate type corrosion inhibitors designed to be
compatible with automotive components. In an industrial application, the silicates will
form a gel on the heat transfer surface which will result in substantial reduction in cooling
capacity and is virtually impossible to remove.
C. Even though uninhibited glycols do lower the freeze point, they are often more corrosive
than water. The corrosion rate of ethylene glycol on iron, for example, is more than 2.5
times faster than plain water. On steel, it is 4.5 times faster.
D. MAINTENANCE RESPONSIBILITY:
A refractometer (shown below) should be
used on a regular basis to determine the
mixture strength according to freeze point.
The freeze point temperature should be 25°F
below the lowest required setpoint (see chart)
or the lowest expected ambient temperature
whichever is lower. Water may evaporate
from the mixture and if you continue to add
a premixed solution eventually you will have
too much glycol. Or, if water/glycol from the
system is spilled during operation and is
made up with straight water the glycol level
will be diluted and the freeze point of the
mixture will not be low enough which can
cause catastrophic damage to the system by
freezing and rupturing the chiller evaporator.
It is necessary to add water or glycol to
maintain proper freeze point temperature. The
refractometer pictured below is accurate and
easy to use for maintaining and checking for
proper glycol levels.
Usa a Misco or equivalent to test your glycol on a regular basis.
Misco Products Model #7084VP 1-800-358-1100
FREEZING POINTSFOR
WATER/PROPYLENE GLYCOL SOLUTIONS
°F
FREEZE POINT
2
32
20
15
10
3
-15
-20
0
-6.7
-9.4
-12.2
-16.1
-20.6
-26.7
°C WATER GLYCOL
1
0
20
25
30
35
45
50
100
80
75
70
65
55
50
PERCENTAGE OF
1. Prophylene glycol.
2. Information shown is a general guide. Check your specific glycol specifications
for actual glycol percentage and freeze protection level.
The coolant freeze point is indicated on the line
between the dark and light areas on the scale. In
this example, the freeze point is about -5°F to -6°F.