January 28, 2021

Improving Cooling Tower Blowdown Operations With Flow Meters

Cooling towers are critical pieces of equipment in HVAC applications because they help optimize system performance and prevent malfunctions. Find out why facilities managers implement flow meters within cooling tower blowdown applications to maintain proper design flow.

The Insider Blog / 3 min read

The cooling tower blowdown process regulates system temperature, which is crucial to the operation of chillers, air conditioners and other HVAC equipment. To maintain accuracy and efficiency within their processes, facilities managers, engineers and other stakeholders use flow meters to monitor the water recirculation process and minimize water loss.

How the Cooling Tower Blowdown Process Works

Cooling towers regulate the temperature of HVAC systems by releasing excess heat into the atmosphere through evaporation. During this process, the concentration of dissolved solids—including magnesium, calcium, chloride and silica—rises, which can cause scaling and corrosion if left unaddressed. Cooling towers flush water out of the system and replace it with fresh water to cool the temperature and reduce the concentration of dissolved solids.

Reducing this level of scale buildup improves system performance and lifespan and reduces the need for maintenance. This process also protects equipment from insufficient cooling and potential malfunctions as well as reduces water waste to earn credits from the municipality. Blowdown meters monitor the process for optimization, including evaporation, by comparing make-up water meters to blowdown meters. Because this evaporated water was not flushed down the train, it cannot be billed as sewer usage and is therefore subject to municipality credits.

Choosing Flow Meters for Your Application

Flow meters help maintain proper design flow within cooling tower blowdown applications by minimizing water loss through evaporation and drift; monitoring and managing blowdown and recirculated water to maintain efficiency; and helping engineers and facilities managers better manage processes. Many stakeholders choose flow meters that can capture low flow measurements with an accuracy of +2% or better. The most commonly selected technologies include:

Nutating Disc: Positive displacement meters feature a simple, efficient design that results in high accuracy and repeatability over the flow meter range. These meters are also rugged and reliable and require minimal maintenance.
Ultrasonic: These non-intrusive meters can be installed without interrupting service or cutting into a pipe. They simply clamp onto a pipe’s exterior, ensuring it never comes in contact with the highly concentrated cooling tower blowdown water.
Electromagnetic: Magnetic meters—also known as mag meters—are often selected for their excellent accuracy and low-flow capabilities. These meters can also have exceptional turndown ratios and repeatability.

Our solution experts recommend nutating disc meters in most cooling tower blowdown applications and are happy to help you find the meter that best fits your unique needs. Learn more about the cooling tower blowdown process and our lineup of flow metering technologies to improve your hydronic operations.