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Heat Exchanger
Refrigerant Circuit #1
Refrigerant Circuit #2
Isolation Ball Valve (2”)
Service Port (3/4”)
Isolation Ball Valve (2”)
Service Port (3/4”)
From Cooling Tower
To Cooling Tower
Header
Header
Connected to City Water
To Drain
Heat Exchanger
Refrigerant Circuit #1
Refrigerant Circuit #2
Isolation Ball Valve (2”)
Service Port (3/4”)
Isolation Ball Valve (2”)
Service Port (3/4”)
From Cooling Tower
To Cooling Tower
Header
Header
Connected to City Water
Cleaning Pump
Cleaning Tank
Fig. 1
City Water
Cleaning Arrangement.
Fig. 2
In Place
Cleaning Arrangement.
Heat Exchangers
higher than the normal flow, and, in the opposite direction.
The difficulties and practicality of this method depends on
the back wash pumping system itself. Another method would
be to back flush each heat exchanger using city water as
opposed to system water (see Fig. 1, City Water Cleaning
Arrangement). The back washing procedure is accomplished
by isolating each individual heat exchanger, and introducing
the city water using a connection hose to the 3/4” service
port to flow in an opposite direction from the "normal" heat
exchanger flow direction. On the opposite 3/4” service port,
connect a drain hose to run to a suitable floor drain. Continue
back flow until all debris is removed.
Chemical in Place Washing
"Chemical Clean In-Place Washing" will typically provide
the best debris removal, even from severely clogged heat
exchangers. It is only necessary to mechanically and
electrically isolate one chiller module at a time which
undergoes the "Clean In-Place Washing". The rest of the
chiller modules can continue to operate to satisfy the cooling
load required. The cleaning tank, pump and pump strainer
should be arranged in the manner shown in Fig. 2, In Place
Cleaning Arrangement. The flow of the cleaning is arranged
in the opposite flow to the normal operational direction.
Connection points are provided using the 3/4” service ports
at each heat exchanger. The cleaning solution used can be
either a detergent or hot water to remove particles and simple
cleaning. If correct water treatment has been implemented
this should provide adequate cleaning for most situations.
The solution can be pumped through the heat exchangers and
allowed to “soak” for a time and then pumped again.
If it is required to remove carbonates, then an acidic wash
should be used. A 2% solution of phosphoric or sulfamic
acids in pure water are generally acceptable. These acid
solutions should only be allowed to circulate within the heat
exchanger for 10 to 15 minutes, followed by a thorough pure
water flush for 10 to 15 minutes.
Hydrochloric or sulfuric
acids must not be used.
In any case, consult the chemical
supplier to establish the correct formulation and handling
process. The materials, which will be exposed to the wash,
are stated on page 15 - Water Treatment.
Once the washing is complete, the solution should be flushed
out completely by pumping clean, fresh water through the
chiller. To achieve a reasonable level of dilution, it may be
required to change the water several times. After cleaning, the
water quality and water treatment should be confirmed.
If you have questions related to the suitability of a solution,
please contact ClimaCool for more information.
