Water Treatment; Antifreeze Protection On The Heat Exchanger - Trane CXAO Installation Operation & Maintenance

Water piping
Hydraulic connection heat recovery
WARNING!
Install a mechanical fi lter at the entrance of each heat
exchanger. Failure to install the fi lter mechanic allows
access of solid particles and / or welding slag inside the
heat exchanger. We recommend the installation of a fi lter
having a fi ltering net with holes not exceeding 0.5 mm in
diameter. The manufacturer can not be held responsible
for any damage to heat exchangers, due to the lack of
the mechanical fi lter.
2.13

Water treatment

Before putting the unit into operation, clean the
hydraulic circuit. Dirt, scales, corrosion residue and other
extraneous material can accumulate inside the heat
Table - Acceptable water quality limits
PH (25°C)
Electrical conductivity S/cm (25°C)
Chloride ion (mg Cl - / l)
Sulphate ion (mg SO 24- / l)
Alkalinity (mg CaCO 3 / l)
2.14 Antifreeze protection on the heat
exchanger
Evaporator and recovery exchangers anti-
freeze protection
All evaporators are supplied with a thermostatically
controlled anti-freeze electrical resistance, which
provides adequate anti-freeze protection up to –25°C.
However, this method is not the only protection
system against freezing, unless the heat exchangers
are completely emptied and cleaned with anti-freeze
solution.
Two or more protection methods should be foreseen
when designing the system as whole:
1. Continuous water fl ow circulation inside piping and
exchangers.
2. Addition of an appropriate amount of glycol inside the
water circuit
3. Additional heat insulation and heating of exposed
piping
4. Emptying and cleaning of the heat exchanger during
the winter season
20
exchanger and reduce its heat exchanging capacity.
Pressure drops can increase, as well, thus reducing
water fl ow. Proper water treatment therefore reduces
the risk of corrosion, erosion, scaling, etc. The most
appropriate water treatment must be determined
locally, according to the type of system and to the local
characteristics of the process water.
For units equipped with plate exchangers the fi lter
should warranty a fi ltration of particles until 0,8 mm.
For units equipped with shell&tube exchangers the fi lter
should warranty a fi ltration of particles until 1,2 mm.
Trane is not responsible for damage to or malfunctioning
of equipment caused by failure to treat water or by
improperly treated water.
6,8÷8,0 Total hardness (mg CaCO 3 / l)
800 Fe (mg Fe / l)
200 Sulphide ion (mg S 2- / l)
200 Ammunium ion (mg NH 4+ / l)
100 Silica (mg SiO 2 / l)
It is the responsibility of the installer and/or of local
maintenance personnel to ensure two or more of the
described antifreeze methods. Continuously verify,
through routine checks, that appropriate anti-freeze
protection is maintained.
Failure to follow the instructions above could result in
damage to some of the unit's components. Damage from
freezing is not covered by the warranty.
200
1.0
Absent
1.0
50
RF-SVX003A-GB