The 8-Steps Of Shutting Down Your Cooling Tower For The Winter

Industrial & Manufacturing Blog

Cooling towers reject excess heat from a buildup of manufacturing processes, lights, people, and computers, even the sunlight that heats up buildings through windows. They tend to operate 24/7, so occasionally they will need to shut down for maintenance or scheduled industrial or seasonal shutdowns like during the winter months.

The Shutdown Process Overview

Since cooling towers act as specialized heat exchangers by using air and fans to cool and evaporate streams of water from a building, they need to shut down periodically so that bacteria and sediment do not corrode and damage the tower's parts. It takes a couple of weeks to go through the shutdown process and the steps must be followed in order.

The Seven Shutdown Steps

You should begin the cooling tower shutdown process two weeks before scheduled maintenance, factory shutdowns, or for the winter off-season. Industrial and manufacturing settings often have many cooling towers, some of varying sizes and types sitting on the roof.

1. Flush the cooling tower and any related cooling tower products, like drift eliminators, thoroughly to reduce material deposits floating around the system. Remove scale in any drift eliminators before adding a protective cooling tower corrosion inhibitor. This step is done two weeks prior to the shutdown.
2. A week before shutting down the cooling towers, remove any accumulated scale and sludge with a spray dispersant designed to break down larger particles into smaller, easier-to-remove particles.
3. Three days before the shutdown, add a dispersant and biocide to remove biofilm and sanitize the cooling system by breaking down bacteria that are harmful to you and your cooling tower system.
4. This step depends on what kind of cooling tower you have: crossflow or counterflow. If you have the crossflow system, you will need to sweep out the hot water distribution basin, flush it out, and refill it. You'll need to clean strainers as well. If you have a counterflow system, you'll have to remove the drift eliminator to visually inspect the nozzles. You will have to do this while the cooling tower is running so you can check for clogged nozzles that need either cleaning or replacement.
5. Controller and chemical feed systems must have the chemical pump lines removed and the pumps flushed with clean water before unplugging. Foot valves should just hang free to dry.
6. Chemical pumps get turned off and sealed up for the winter. Flush the chemical control water lines. Inspect and clean the conductivity and pH probes as necessary. 
7. Finally, brush the chiller's condenser tubes. Store them without the end bells. This way air can flow through freely and when you turn everything back on in the spring you won't risk damage or bacteria buildup that can sicken those in the building.

Of course, there are other cooling tower parts you can inspect, clean, or replace as necessary. A few examples are capacitors, fan belts, and motors. You may need extra steps depending on the size of your cooling towers, but these are the basic 8-steps that you can count on needing to be done. 

15 November 2021