Operation
the fluid cooler fan, execute one of the two alternative biocidal treat- ment programs described in the following:
•Resume treatment with the biocide which had been used prior to shutdown. Utilize the services of the water treatment supplier. Maintain the maximum recommended biocide residual (for the specific biocide) for a sufficient period of time (residual and time will vary with the biocide) to bring the system under good biological control or
•Treat the system with sodium hypochlorite to a level of 4 to 5 mg/L (ppm) free chlorine residual at a pH of 7.0 to 7.6. The chlorine re-
sidual must be held at 4 to 5 mg/L (ppm) for six hours, measurable with standard commercial water test kits.
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 fluid cooler storage vessel (collection basin, drain down tank, etc.) without circulating stagnant water over the fluid cooler or operating the fluid cooler fan.
After biocidal pretreatment has been successfully completed, cooling water may be circulated over the tower 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.
Fluid Cooler 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 cools the process fluid is established by the system heat load and the amount of fluid being circulated, in accordance with the follow- ing
The fluid cooler establishes only the cold process fluid temperature attainable under any operating circumstance.
Range – °C = | Heat Load (kilowatts) | ➠ | |
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Liters/sec x 4.187 | |||
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