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IDX-OM-Y002
Chapter 5
Checks
, Maintenance and Adjustment
5.2
Regular maintenance
IDF190D/240D Series
5-2
5.2 Regular maintenance
5.2.1
Maintenance for water-cooled condenser
When a water-cooled air dryer is used for a certain amount of time, the compression performance
decreases due to the contamination of the cooling water side of the water-cooled condenser.
Because of this, compression pressure abnormally increases, starting the protection equipment
installed in the air dryer, stopping the air dryer operation.
When the air dryer is operated, perform maintenance for the water-cooled condenser after reading
8-1 and 8-2 below carefully.
(1) Cooling water
Ground water or tap water may be used for cooling water for water-cooled condenser. There are 2
types of method for cooling; once-through water cooling and circulated water cooling.
With once-through type, ground water or tap water is continuously supplied to the water-cooled
condenser, discharging warmed water to the outside. This method is used where cooling water
source is abundant.
With circulated type, heat is absorbed by water-cooled condenser and warmed water is cooled down
in the cooling tower for reuse.
In most cases, cooling performance of the water-cooled condenser is deteriorated by the
contamination of the cooling water of adhesion of scales.
(2) Cooling Water Quality Standard
1
)
Water quality standard
As a guideline for cooling water quality which does not cause abnormal level of contamination or
scale, JRA-GL-02-1994 Guideline of Water Quality for Refrigeration and Air Conditioning
Equipment shall be referred. Table 4 -1 shows the values.
Table 4-1
The water that passes through the water-cooled condenser is referred to as cooling water. This applies
to both once-through and circulating type condensers.
Items
Cooling water system
Circulating type
Non circulating type
Circulating fluid
Make-up water
Non circulating water
Sta
n
d
a
rd
i
te
m
s
pH
[25
o
C]
6.5~8.2
6.5~8.0
6.8~8.0
Conductivity (mS/
m
)
[25
o
C]
80 or less
30 or less
40 or less
Chloride ion (mg/L)
200 or less
50 or less
50 or less
Sulphate ion (mg/L)
200 or less
50 or less
50 or less
Acid consumption
[pH4.8](mgCaCO
3
/L)
100 or less
50 or less
50 or less
Total hardness (mgCaCO
3
/L)
200 or less
70 or less
70 or less
Calcium hardness (mgCaCO
3
/L)
150 or less
50 or less
50 or less
Ion state silica (mgSiO
2
/L)
50 or less
30 or less
30 or less
Ref
e
re
n
c
e
i
te
m
s
Iron(mg/L)
1.0 or less
0.3 or less
1.0 or less
Copper (mg/L)
0.3 or less
0.1 or less
1.0 or less
Sulfide ion (mg/L)
Should not be
inspected.
Should not be
inspected.
Should not be
inspected.
Ammonium ion (mg/L)
1.0 or less
0.1 or less
1.0 or less
Residual choride (mg/L)
0.3 or less
0.3 or less
0.3 or less
Free carbon dioxide (mg/L)
4.0 or less
4.0 or less
4.0 or less
Stability index
6.0~7.0 or less
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