MIL-HDBK-1165
concentration of impurities in the water left behind. The solids
are introduced into the water through the make-up water, from the
air used in evaporation, or through corrosion in the re-
circulating plumbing. Bleed-off is the only use of water that
can effectively be reduced by water conservation.
5.4.1.2
Operation and Maintenance Procedures. The water
savings realized by implementing the following suggestions depend
on your individual cooling system setup.
a)
Locate and repair leaks.
Repair any malfunctioning
equipment.
b) If a conductivity meter is installed, change the
method of releasing bleed-off from a batch method to a continuous
method. The batch method involves discharging a large quantity
of bleed-off automatically when the water's conductivity reaches
a certain preset level. This causes fluctuations in the
conductivity of the circulating water and causes the average
conductivity to be lower than necessary. Continuous, low volume
bleed-off keeps the conductivity steady at the desired level,
which conserves water and reduces the need for treatment
chemicals.
c) Reduce the amount of bleed-off to the minimum
volumes that still produce acceptable circulating water quality.
d) Controlling the amount of bleed-off by the use of
chemical additives to the water can be considered a maintenance
procedure once established. (Chemical treatment methods are
discussed in 5.4.1.5)
5.4.1.3
Retrofits. The following suggestions will aid in
reducing the amount of bleed-off to minimum levels consistent
with good operating practices:
a) Install flowmeters to monitor the flow of both
make-up and bleed-off water to determine any required flow
changes.
b) Install a conductivity meter to determine proper
frequency of bleed-off. (Refer to par. 5.4.1.2 (2))
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