MAINTENANCE PROCEDURES
9
MECHANICAL CLEANING
Keeping your evaporative cooling equipment (and the associated
system) clean will maintain its efficiency and help to prevent
uncontrolled bacteriological growth. The recommended cleaning
procedures are described below :
1. Disconnect fan and pump motor(s) and shut off make-up supply.
2. Remove screens, eliminators, access panels and doors and
drain system. Do not remove sump strainer.
3. Clean debris from exterior and fan(s) with soft brush, if
necessary use water and soap.
4. Clean interior with (soap) water and soft brush, if necessary use
high pressure water jet.
5. Remove any debris from water distribution system and clean any
nozzles if clogged. If necessary nozzle and grommet may be
removed for cleaning.
6. Remove debris from heat transfer section (coil/fill) . Do not use
steam or high pressure water to clean cooling tower wet deck
surface.
7. Flush with clean water and drain to remove accumulated dirt.
8. Remove, clean and replace sump strainer(s).
9. Clean debris from screens and eliminators with water jet and
install.
10.Remove debris from access doors and panels with soft brush
and (soap) water and install.
11.Close drain and open make-up supply. Fill system to overflow
level with clean water.
DISINFECTION
Disinfection of your cooling system may be needed in case of high
concentration of aerobic bacteria and/or Legionella. Disinfection is
also recommended for evaporative cooling systems with known or
suspected high bacteriological levels, prior to a cleaning procedure.
Some local or national guidance also recommends disinfection
prior to initial start up, after a prolonged shut down, after routine
cleaning operations or when significant alterations have been made
to the cooling system.
Disinfection must be carried out in accordance with a proper
procedure and take into account the safety of the cleaning and
disinfection staff.
Typically disinfection is achieved using a sodium hyperchloride
solution to maintain a residual value of 5 - 15 mg/l of free chlorine
and circulate this around the system for up to 6 hours. Higher
chlorine levels for a shorter period are possible, but require a higher
level of corrosion protection than galvanized steel only. Consult your
BAC Balticare representative for further information.
Excessive levels of chlorine must be avoided as this quickly can lead
to corrosion and damage to your system.
Chlorinated water should be de-chlorinated before draining and
after disinfection the system must be thoroughly flushed through
with clean water.
Note: A proper regularly monitored biocide programme reduces the need for
cleaning and disinfection actions significantly.
Cleaning Procedures
