Brady Blog- Trends and Talk

​Understanding And Preventing Legionnaires’ Disease

Thursday, March 23, 2017

Understanding And Preventing Legionnaires’ Disease

The Legionella bacteria was named after an outbreak in 1976 at the American Legion Convention that lead to 221 cases of illness and 34 deaths. The legionella bacteria can cause the serious respiratory disease, Legionellosis, or what is commonly referred to as, Legionnaires’ disease. As a facility owner, it’s important to recognize that cooling towers are susceptible to harboring and spreading the bacteria. Regular testing and proper treatment for Legionella can help protect your facility and surrounding area.

Knowing The Risk Legionella is a waterborne bacterium that can live and grow in all surface water, including ground water and wastewater. The bacteria thrive in the presence of a biofilm (slime) and can live inside amoebas, protozoan, and other microbiological organisms in the fouled water. Water between 75°Fand 115°F is the ideal environment for the Legionella bacteria, making cooling towers one of the main distribution methods of the bacteria. Hot tubs, decorative fountains, large plumbing systems, and hot water tanks and heaters are also prone to spreading the bacteria.

Spreading Legionella Legionella can only be contracted by inhaling contaminated mist or water droplets. It cannot be transmitted person to person. Cooling towers produce small water droplets that are propelled outside of the tower by thefan, making them a common source for spreading the bacteria.

Who’s At Risk? The majority of generally healthy people do not get sick after exposure to the Legionella bacteria. People with weakened immune systems, chronic lung disease, current or former smokers, and people over 50 are most vulnerable to the disease.

Preventing And Controlling The Bacteria The first line of defense against Legionella is a water treatment program that uses a dual alternating biocide program. One biocide needs to be an oxidizing biocide, like stabilized bromine, and the other needs to be a non-oxidizing biocide with or without a dispersant. The two chemicals work together to increase the effectiveness of your water treatment program, and can destroy and control the microbiological growth that canharbor the potentially dangerous bacteria.

When To Test There is currently no legislation mandating Legionella testing or the frequency but, there are recommendations based upon the facility type. Industrial sites should be tested at least twice a year, while office buildings should be tested quarterly. Schools, hospitals, and other locations where people are at a high risk of contracting the bacteria should be tested monthly.

If your facility receives a positive result after testing for Legionella, a water treatment technician will review the results and determine if system disinfection is necessary.

To learn more about Brady’s water treatment program and how it can help protect your facility fromLegionella, visit bradyservices.com/services or call (800) 849-1915.

 


Protecting And Preventing White Rust In Galvanized Cooling Towers

Wednesday, March 08, 2017

Protecting And Preventing White Rust In Galvanized Cooling Towers

Changes in the galvanizing process and water treatment chemistry have led to an increase in white rust in cooling towers and evaporative condensers. White rust, once it has formed can reduce the lifespan of a cooling tower from approximately 15-20 years to as little as 3 - 5 years if left untreated.

Understanding White RustWhen looking at a galvanized piece of steel, have you noticed white deposits on the surface? White rust is a white deposit that forms on wet galvanized steel surfaces, and the white deposit is the loss of zinc in the galvanized coating on the steel. As the zinc is lost on the surface, the base metal underneath is left vulnerable to corrosion. Once white rust has formed, it can be challenging to control, which is why protecting equipment is key in preventing irreversible damage to a cooling tower.

Protecting With PassivationManufacturers of galvanized cooling towers recognize the risks of corrosion and white rust and defend the steel by applying a protective coating containing zinc. The zinc bonds to the steel underneath, forming a sacrificial layer. If the water in the basin has a pH out of range and contacts steel that has not been passivated, the water will begin to strip away the sacrificial layer through oxidation, exposing the base metal, and leaving it open to corrosion.

Passivation process could take up to 12 – 14 weeks where the zinc coating is converting into a more stable form of zincthat can better withstand long-term exposure to various conditions in a cooling tower. The process uses specialized chemical additions and strict pH control to maintain specific water chemistry conditions. Passivation should be completed before a new tower has a heat load added. If the tower is already online it can still be passivated, but can be more difficult to accomplish successfully, and may require specific chemical additions to control the water’s pH and other parameters.

When white rust has formed on a cooling tower, the water treatment plan will pivot from prevention to control. During tower cleanups, the technician can scrape and brush away the rust, and coatings and paint can be applied. However, the inability to reach every piece of metal inside the equipment can make it difficult to successfully repair, and white rust can continue to develop.

What’s At Risk?  Galvanized metal in a cooling tower that is exposed to water must be passivated to prevent white rust. Even towers made from stainless steel,fiberglass, and plastic can contain pieces of hardware that are galvanized steel, leaving the tower susceptible to white rust.

Prevention is crucial in preventing white rust, so if you are planning to purchase a new galvanized cooling tower or concerned about an existing cooling tower, visit bradyservices.com/services.

 

 


Increasing the Effectiveness Of A Water Treatment Program

Tuesday, February 14, 2017

The goal of a good water treatment program should be to ensure that the water has constant contact with heat exchange surfaces and is free of biological fouling. Biological growth, scale deposition, and corrosion can force equipment to work harder because of reduced ability of the water to contact these surfaces. In order to increase the effectiveness of a water treatment plan, water treatment professionals recommend a dual alternating biocide program.

Oxidizing Biocides

Biocides are chemicals used to eliminate bacteria and algae found in cooling towers and other recirculating cooling systems. All biocides can be divided into two major classes- oxidizing and non-oxidizing. Each type of biocide approaches biological organisms in a different way.

Oxidizing biocides take a “shot gun” approach to destroying bacteria and biological growth. These biocides attack the cell structure of the organism to destroy the cell and ultimately kill the organism. Oxidizing biocides are effective because of the speed and nature of their approach and organisms are unable to build up a resistance to the chemicals used to treat the water.

However, there are a few drawbacks with the use of oxidizing biocides. These chemicals can increase the corrosiveness of water. Some oxidizing chemicals used in water treatment programs can also create undesirable byproducts that are bad for the environment.

All water treatment programs require consistent monitoring of water conditions and chemical levels. Oxidizing biocides can increase the need for observation because they can interact with other corrosion control chemicals used in the program, and render them less effective.

Non- Oxidizing Biocides

A non-oxidizing biocide attacks biological growth in a different way, by interrupting the organism’s metabolism, and effectively poisoning the cells to kill them. This class of biocides targets specific organisms and specific cellular processes, taking a “rifle” approach to treatment.

An added benefit of non-oxidizing biocides is that they can have little to no impact on other chemicals used to treat corrosion and scale. Unfortunately, due to the vast number of microorganisms that could exist in any recirculating cooling system, as a non-oxidizing biocide is used the organisms can become resistant to that particular chemical are not affected and continue to grow in the water and require the attention of a water treatment technician.

How Does A Dual Alternating Biocide Program Work?

Continuous use of one single biocide in a water treatment program can lead to resistant flora and damaging conditions in the water, making a dual alternating approach ideal to control the biological growth. In a dual alternating biocide program, both oxidizing and non-oxidizing biocides are fed into the system on an alternating slug dosage based off of the continued monitoring of water conditions. Often times, to increase the effectiveness of non-oxidizing biocides, a dispersant is added to loosen and penetrate bio-films attached to metal surfaces in a system which allows the biocide to be more effective.

If you are interested in learning more about a dual alternating biocide program and how it can improve water conditions in your facility’s cooling system, visit bradyservices.com/services or call (800) 849-1915.


Benefits of a Water Treatment Program

Friday, January 27, 2017

As a facility owner, you know that water plays a vital role in heating and cooling systems and process manufacturing. But, did you know that managing the quality of the water used in these systems is equally important? A water treatment program can help ensure your equipment continues to operate efficiently and safely for years to come.

Energy Efficiency

When the water used in cooling towers, air washers, steam boilers, and associated closed loop systems is left untreated, the results can be excessive microbiological growth, scaling, and corrosion in the equipment. This fouling creates a barrier on heat exchange services of your equipment that can interfere with the water’s ability to exchange heat, forcing the systems to work harder and increasing your facility’s energy costs.

Protecting Your Equipment

Corrosion can lead to irreversible damage of your equipment. It can cause pitting and rust that may bore holes and weaken the infrastructure.A water treatment technician will examine the equipment to determine the cause of corrosion and will treat the water to alleviate the issue. The technician will then monitor the corrosion rate to ensure it stays within the industry standard.

Safety

Uncontrolled microbiological growth in heating and cooling systems can cultivate potentially dangerous bacteria, such as legionella. This waterborne bacterium thrives in water between 75° and 115° and can be protected in a biofilm, making cooling towers ideal for growing the bacteria. Regular bacteria tests and treating the water can help ensure your facility does not develop or spread legionella.

To learn more about Brady’s water treatment program, and how it can help your facility, visit: bradyservices.com/services.html