Water-Efficient Technology Opportunity: Side Stream Filtration for Cooling TowersThe Federal Energy Management Program (FEMP) identified cooling...
Published on by Water Network Research, Official research team of The Water Network
The Federal Energy Management Program (FEMP) identified cooling tower side stream filtration as a technology that offers key benefits to the federal sector, including the potential to reduce energy and water use, decrease operating costs, and extend cooling equipment life. This overview provides agencies with key information to deploy side stream filtration systems that may otherwise be overlooked.
Cooling towers reject heat from buildings and/or processes through evaporation of water to the atmosphere. Cooling towers are generally exposed to the surrounding environment and move large volumes of air through water to reject heat to the atmosphere. This makes them susceptible to dirt, debris, and biological contamination.
The combination of these environmental factors, cooling tower process, and source water quality contribute to four primary treatment concerns encountered in most open-recirculating cooling systems: corrosion, scaling, fouling, and microbiological activity. A portion of water must be periodically flushed from the system in a process called "blowdown" to keep these concerns under control.
Filtration and/or treatment can be used minimize these concerns, increasing the "cycles of concentration," e.g., the number of times water is recirculated in the cooling tower before blowdown is required. Increasing the cycles of concentration reduces the amount of water used for blowdown.
Technology Description
Side stream filtration systems constantly filter a portion of water to remove suspended solids and organics, reducing the likelihood of fouling, scaling, and microbiological growth. Side stream filters may be installed parallel to the collection basin or between the pump and heat exchanger as shown in Figure 1.
Illustration shows two locations for a side stream filter on a cooling tower.
Figure 1. Cooling tower with two possible locations for side stream filtration
Technology Benefits
Technology Considerations
Technology Options
Four common and commercially available side stream filtration technologies are described below. This information is intended to provide a brief overview of each technology and its advantages and disadvantages.
Individual system requirements should be evaluated when choosing the most appropriate technology for a given cooling tower. Cooling tower performance and filtration requirements can vary significantly by cooling tower design and environmental conditions.
Centrifugal Separators
Automatic Screen Filters
Plastic Disc Filters
Sand Filters
Technology Option Comparison
Table 1 provides an overview of the side stream filtration technologies and key characteristics.
Attached link
https://www.energy.gov/cmei/femp/water-efficient-technology-opportunity-side-stream-filtration-cooling-towersTaxonomy
- Filtration
- Technology
- Filters
- Filtration
- IT
- Cooling tower maintenance and repairs