Operating a cooling tower requires technical knowledge to assist in the tower’s ability to cool the system with water’s heat transfer abilities. Although the system may function properly with high water usage, there is a significant cost to all of that water. There are various stages in cooling tower’s operation such as cycling, blowdown, etc. where water can be saved. This leads to higher efficiency and benefits such as “Energy Star Certification.” Efficient systems cost less for water and are more environmentally friendly.
The efficiency of water usage in cooling towers can be measured by the number of times water can be cycled through the system. This is also known as cycles of concentration. As pure water evaporates from the cooling tower, the dissolved solids in the water remain behind and steadily increase in concentration. The ratio of the concentration of dissolved solids in the cooling tower water to the concentration of dissolved solids in the make-up water is used to measure the cycles of concentration.
Make-up water can be described as the water used to compensate for the loss of water through evaporation and system bleed. The composition of the make-up water determines how many cycles of concentration may be attained in a cooling tower. When the pH and calcium of the make-up water is too high, the number of cycles of concentration is limited by the solubility and possible precipitation of scale.
Water and sewer savings are significantly higher at maximized cycles of concentration. If make-up water is limiting your system to less than 3 cycles, feeding acid may provide a more economical operation for your cooling tower.
To have an expert develop a plan to reduce water usage, or any other water treatment needs contact Chardon Laboratories here.
Use centrifugal separator filtration systems to capture possible contaminants in the cooling tower. Contaminants such as microbiological growth stick to surfaces of the cooling tower. This impedes heat transfer as the water cycled through the system is not in direct contact with the surface. Additionally, contaminants can cause corrosion, which means uneven surfaces, holes, and pockets for more microbiological bacteria to grow. Filters aim to catch these contaminants, so clean water can pass through to clean surfaces.
Acid can be useful as it balances pH and can help prevent scale.
Additionally, adding acid will neutralize alkalinity. Sulfuric acid reacts with natural carbonate alkalinity in the water forming carbon dioxide (which is dispelled to the atmosphere) and an all-natural compound called sulfate.
The amount of acid required depends on the alkalinity of your make-up water. Certain areas of the country have very hard water. Additionally your desired cycles of concentration can make a difference. You will need to add enough acid to neutralize the alkalinity to a point where the calcium hardness remains soluble. This will require you to consider what the alkalinity will be once the make-up water has cycled up and after the acid is added.
It is important to understand how alkalinity is “cycled up” in systems and it is dependent on many factors that will vary from water source to water source.
To have an expert check your system’s acid and water usage contact Chardon Laboratories here.
