SPX Cooling Technologies Marley MH 05-116E - Manual (Page 21)

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Fluid Cooler Cleaning:
Any evaporative-type fluid cooler must be thoroughly cleaned on a
regular basis to minimize the growth of bacteria, including Legionella
Pneumophila, to avoid the risk of sickness or death. Service personnel
must wear proper personal protective equipment during decontami-
nation. Do NOT attempt any service unless the fan motor is locked
out.
Operators of evaporative cooling equipment, such as closed circuit cool-
ing towers, should follow maintenance programs which will reduce to an
absolute minimum the opportunity for bacteriological contamination. Public
Health Service officials have recommended that “good housekeeping”
procedures be followed, such as: regular inspections for concentrations
of dirt, scale, and algae; periodic flushing and cleaning; and the following
of a complete water treatment program including biocidal treatment.
The visual inspection should take place at least once a week during the
operating season. The periodic flushing and cleaning should be done
before and after each cooling season, but in any event at least twice a
year. The louvers, drift eliminators, easily accessible fill surfaces and the
coil should be flushed by use of a moderate-pressure water nozzle, being
careful not to cause physical damage. A reliable water treatment program
should be installed and maintained. Filtration devices may be employed
to reduce the suspended solids concentrations, thus increasing the ef-
fectiveness of the water treatment program. See Fluid Cooler Startup
instructions on page 13.
Blowdown:
A fluid cooler cools water by continuously causing a portion of it to
evaporate. Although the water lost by evaporation is replenished by the
makeup system, it exits the tower as pure water—leaving behind its
burden of dissolved solids to concentrate in the remaining water. Given
no means of control, this increasing concentration of contaminants can
reach a very high level.
In order to achieve water quality which is acceptable to the fluid cooler, the
selected water treatment company must work from a relatively constant
level of concentrations. This stabilization of contaminant concentrations
is usually accomplished by blowdown, which is the constant discharge
of a portion of the circulating water to waste. As a rule, acceptable levels
on which to base a treatment schedule will be in the range of 2-4 con-
centrations. The following table shows the minimum amount of blowdown
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Maintenance
Warning