YORK INTERNATIONAL
69
FORM 160.60-O1
GENERAL
Maintenance of condenser and cooler shells is important
to provide trouble free operation of the unit. The water
side of the tubes in the shell must be kept clean and free
from scale. Proper maintenance such as tube cleaning,
and testing for leaks, is covered on the following pages.
CHEMICAL WATER TREATMENT
Since the mineral content of the water circulated through
coolers and condensers varies with almost every source
of supply, it is possible that the water being used may
corrode the tubes or deposit heat transfer resistant scale
in them. Reliable water treatment companies are avail-
able in most larger cities to supply a water treating proc-
ess which will greatly reduce the corrosive and scale form-
ing properties of almost any type of water.
As a preventive measure against scale and corrosion and
to prolong the life of cooler and condenser tubes, a chemi-
cal analysis of the water should be made preferably be-
fore the system is installed. A reliable water treatment
company can be consulted to determine whether water
treatment is necessary, and if so, to furnish the proper
treatment for the particular water condition.
CLEANING COOLER AND CONDENSER TUBES
Cooler
It is difficult to determine by any particular test whether
possible lack of performance of the water cooler is due to
fouled tubes alone or due to a combination of troubles.
Trouble which may be due to fouled tubes is indicated
when, over a period of time, the cooling capacity de-
creases and the split (temperature difference between
water leaving the cooler and the refrigerant temperature
in the cooler) increases. A gradual drop-off in cooling ca-
pacity can also be caused by a gradual leak of refrigerant
from the system or by a combination of fouled tubes and
shortage of refrigerant charge. An excessive quantity of
oil in the cooler can also contribute to erratic performance.
Condenser
In a condenser, trouble due to fouled tubes is usually
indicated by a steady rise in head pressure, over a period
of time, accompanied by a steady rise in condensing
temperature, and noisy operation.
TUBE FOULING
Fouling of the tubes can be due to deposits of two types
as follows:
1. Rust or sludge, which finds its way into the tubes and
accumulates there. This material usually does not
build up on the inner tube surfaces as scale, but does
interfere with heat transfer. Rust or sludge can gener-
ally be removed from the tubes by a thorough brush-
ing process.
2. Scale, due to mineral deposits. These deposits, even
though very thin and scarcely detectable upon physi-
cal inspection, are highly resistant to heat transfer.
They can be removed most effectively by circulating
an acid solution through the tubes.
TUBE CLEANING PROCEDURES
Brush Cleaning of Tubes
If the tube fouling consists of dirt and sludge, it can usu-
ally be removed by means of the brushing process. Drain
the water sides of the circuit to be cleaned (cooling water
or chilled water) remove the heads and thoroughly clean
each tube with a soft bristle bronze brush. DO NOT USE
A STEEL BRISTLE BRUSH. A steel brush may damage
the tubes.
Improved results can be obtained by admitting water into
the tube during the cleaning process. This can be done
by mounting the brush on a suitable length of 1/8" pipe
with a few small holes at the brush end and connecting
the other end by a means of a hose to the water supply.
The tubes should always be brush cleaned before acid
cleaning.
Acid Cleaning of Tubes
If the tubes are fouled with a hard scale deposit, they
must be acid cleaned. It is important that before acid
cleaning, the tubes be cleaned by the brushing process
described above. If the relatively loose foreign material is
removed before the acid cleaning, the acid solution will
have less material to dissolve and flush from the tubes
with the result that a more satisfactory cleaning job will
be accomplished with a probable saving of time.
COMMERCIAL ACID CLEANING
In many major cities, commercial organizations now of-
fer specialized services of acid cleaning coolers and con-
densers. If acid cleaning is required, YORK recommends
the use of this type of organization. The Dow Industries
Service Division of the Dow Chemical Company, Tulsa,
Oklahoma, with branches in principal cities is one of the
most reliable of these companies.
TESTING FOR COOLER AND CONDENSER TUBE
LEAKS
Cooler and condenser tube leaks in R-134a systems may
result in refrigerant leaking into the water circuit, or water
leaking into the shell depending on the pressure levels. If
refrigerant is leaking into the water it can be detected at
CONDENSERS AND COOLERS
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