Below are a few guidelines to follow when preparing a cooling tower for shutdown that will ensure your system remains protected throughout the winter and starts up again problem-free when spring rolls around.
Preparing Cooling Tower for Seasonal Shutdown
Preparing for Shutdown/Layup
- Two to three days prior to the cooling tower shutdown, increase the bleed-off to reduce the amount of solids in the system. Reduce the bleed-off set point to 1-1.5 cycles (1-1.5 x makeup conductivity).
- One day prior to the shutdown, add twice the normal amount of non-oxidizing biocide and recirculate for 4 to 6 hours. If a non-oxidizing biocide is not used, an oxidizing biocide can be used as an alternative.
- Sweep off the distribution deck while the system is operating. Drain down the tower and wash out the tower fill and sump. Remove and clean all strainers. Reinstall the strainers.
- Isolate the tower controllers. Remove and protect the tower conductivity probe and shut the controller off (do not unplug the controller power source).
- Refill the tower system (it does not need to be refilled to the operating level in order to reduce the system volume). Vent all chillers to ensure that they are completely filled with water. Close the vents.
- Add layup water treatment to the tower and recirculate the system for a minimum of 8 hours using all pumps.
- Completely drain the system from the lowest point.
- Clean and flush the chemical feed pumps. Place the suction line (foot valve) of each pump in water and operate the pump to completely flush it of treatment products. Leave the foot valve out of the chemical tank for the off-season.
- Open the chiller condenser end bells and brush the tubes. This should be done right away to avoid stagnant water sitting in the chiller.
- Store the chiller with the end bells removed when not in use.
By following these shutdown instructions, you will be guaranteed a worry-free winter and a trouble-free start-up in spring!