Operation - SPX Marley LW032 B Series User Manual

10

operation

If the fluid cooler has been in operation and then shut down for a duration
of time and not drained, perform one of the two previous biocidal treatment
programs directly to the recirculating water storage vessel (collection
basin, drain down tank, etc.) without circulating stagnant water over the
coil(s) or operating the fan(s).
After biocidal pretreatment has been successfully completed, cooling
water may be circulated over the coil(s) with the fan off.
When biocidal treatment has been maintained at a satisfactory level for
at least six hours, the fan may be turned on and the system returned to
service. Resume the standard water treatment program, including biocidal
treatment.
Operation
General:
The cold process fluid temperature obtained from an operating fluid cooler
will vary with the following influences:
1. Heat load: With the fan in full operation, if the heat load increases, the
cold process fluid temperature will rise. If the heat load reduces, the cold
process fluid temperature will reduce.
Note that the number of degrees ("range") through which the fluid cooler
Range – °F
cools the process fluid is established by the system heat load and the
amount of fluid being circulated, in accordance with the following formula
Range – °C
which is only valid for 100% water as the process fluid:
The fluid cooler establishes only the cold process fluid temperature at-
tainable under any operating circumstance.
2. Air wet-bulb temperature: Cold process fluid temperature will also vary
with the wet-bulb temperature of the air entering the fluid cooler. Reduced
wet-bulb temperatures will result in colder process fluid temperatures.
However, the cold process fluid temperature will not vary linearly with the
wet-bulb. For example, a 20°F reduction in wet-bulb may result in only a
15°F reduction in cold process fluid temperature.
3. Fluid flow rate: Increasing the process fluid flow rate (gpm) will cause
a slight elevation in cold process fluid temperature, while reducing the
Heat Load (Btu/hr)
=
gpm x 500
or — in SI units
Heat Load (kilowatts)
=
Liters/sec x 4.187