Cooling Tower Cleaning From a Watery Perspective — Dive, Dive, Dive

One recurring challenge for every utility plant cooling system is cooling tower cleaning. That’s mainly due to deposits of particulates being brought into the cooling system from outside the system as well as particulates generated from within the system itself. This challenge is exasperated when the cooling tower is submerged in water. The types of particulates can vary greatly depending on the treatment, nature of the water and the location of the plant. For example, below is a video of a diver cleaning a potable water tower filled with sediment.

A few years ago, while transiting the Prussian Gulf and stopping off in Bahrain, (home of the U.S. Navy 5th Fleet), I was asked to assist in the evaluation of a cooling problem at a major power plant. As I worked my way methodically through, the issue became obvious to me – major inefficiency of the cooling towers!

Cooling tower cleaning is one of the most important procedures you can perform to boost system performance. By virtue of its open-air design, a cooling tower is a giant collector for atmospheric dirt (in my example, desert sand), mineral deposits, and corrosion by-products. All of this ends up in the basin, which left unattended, will eventually fill up with water-displacing sludge.

Like any other piece of machinery, a cooling tower needs periodic maintenance. If it doesn’t operate in a distinguished manner, neither will your plant. If it’s out of commission, so is your facility.

Traditional maintenance methods usually involve costly shutdowns, manpower, vacuum trucks and expensive disposal of hazardous material. Scheduling required maintenance is often difficult…and sometimes impossible.

Diving the tower is an innovative and cost saving solution to these problems and it keeps your cooling tower on line! Using a vacuum separation system, a diver can clean a tower basin, conduct visual or video inspections, and make repairs in less time — and at far less expense than with any other method. And the bonus, as I said earlier, is that a diver can do the whole job while the tower stays on line!

This is done by using a cooling tower vacuum separation system and a series of separators — the resulting solids left behind will pass a paint filter test. The material can then be deposited in any landfill as non-hazardous waste at a fraction of the cost normally associated with disposal.

Here in the United States, finding an experienced & qualified diving company is extremely important! The diving company should conduct its diving operations in accordance with 29 CFR 1910.430 OSHA standards, 46 CFR U.S.C.G regulations, and the Association of Diving Contractors Consensus Standards.

Using surface supplied certified breathing air, each diver is dressed in a totally sealed diving dry-suit — the same as when we conduct nuclear diving operations. All divers should be trained in confined space entry procedures. Two-way communications are maintained through the diver’s umbilical.

Working closely with plant operations personnel, all lock out/tag out procedures should be monitored and a Job Safety Analysis (J.S.A.) should be conducted prior to the start of diving operations.

In the mean time don’t forget to:

• Check the casing, basin, and piping for corrosion and decay. Without proper maintenance, cooling towers may suffer from corrosion and decay. Welded repairs are especially susceptible to corrosion. The protective zinc coating on galvanized steel towers is burned off during the welding process. Prime and paint any welded repairs with a corrosion-resistant coating.
• Properly seal all cracks, holes, gaps, and door access panels. Leaks in the cooling tower casing may allow air to bypass the fill.
• Remove dust, scale, and algae from the fill, basin, and distribution spray nozzles to maintain proper water flow.

Next Steps:

• Check out our learning center on how best to maintain your facility’s existing cooling tower.
• Subscribe to our blog to stay informed on the latest HVAC maintenance news and insight.
• Work smarter by using inspection and test equipment to better understand system performance and efficiency.
• Stay up to date on facility maintenance tools such as chiller tube cleaners, boiler tube cleaners, hose/pipe cleaners, descaler systems, industrial vacuums, commercial pressure washers, and drain cleaners.

Vince DaSilva
Goodway Blogging Team