Filtration for the Removal of Suspended Solids from Cooling Water Used in Power Generation

Most of the electricity in the US is generated by thermoelectric power plants that use fossil fuels (i.e. coal or natural gas) or nuclear fuel. The fuel is used to boil water to generate steam to turn turbines that generate electricity. Once the steam is used, it must be cooled.

Power generation and water consumption are linked together. As the demand for electricity increases, so does the demand for cooling water.

There are several sources for the cooling water, including:


  • Cooling Tower
  • Surface Water (River, Lake, Reservoir, Ocean) and Well Water
  • City Water and Recycled Water

Once-through cooling is, by far, the most common method. In once through cooling, water is pumped from a river, lake, reservoir or ocean and then returned directly back to the source. There are pros and cons to once-through cooling. The cons, such as water scarcity and thermal pollution are leading the industry to evaluate alternate cooling options.

The use of recirculating cooling systems such as cooling towers, and the use of recycled water is increasing.

All cooling water requires filtration! Cooling tower water, recycled water and surface water supplies can be contaminated by airborne debris, silt, sand, pollen, algae, and other suspended solids. All these water sources can also be contaminated with pipe scale and corrosion by-products. As the contaminants circulate through the system and deposit on the heat transfer surfaces, they cause a reduction in heat transfer efficiency and reduced power generation efficiency. When you lose heat transfer efficiency, then you need to pump more cooling water to realize the same cooling. The net effect of contamination is increased water consumption and reduced power generation efficiency.

Fouled piping and heat exchange surfaces can result in:

  • Higher Energy Costs
  • Lower Productivity
  • Increased Chemical Costs (in recirculating cooling systems)
  • Higher Water Usage, and
  • Increased Equipment and Infrastructure Maintenance.

Filtration of cooling water is often overlooked; but cleanliness of the cooling water can have significant impact on productivity and cost of power generation. The best in class choices for removal of suspended solids are ZGF Spring Filter and Tornado centrifugal separator technologies.

Water is also used for pollution control. Wet air scrubbers and Wet Electrostatic Precipitators (WEP) are devices designed to remove contaminants or impurities from a gas stream utilizing water. The need to remove the contaminants may be necessary for process, environmental (i.e. pollution control), and / or health & safety reasons.

Spray nozzle protection is critical. Clogged nozzles will negatively impact the effectiveness of the nozzles and thus the process. Filtration is highly recommended for spray nozzle protection. The best in class choices for removal of suspended solids are ZGF Spring Filter and Tornado centrifugal separator technology.

Nozzles are designed to perform a specific function. Nozzle performance is dependent upon maintaining the design criteria for flow, pressure, coverage pattern and atomization. Effective and efficient filtration will help keep the nozzles clear of debris enabling the nozzles to consistently perform as designed.

Oversized particles as well high quantities of very small particles will plug nozzle orifices. Once plugged, the spray becomes uneven and inconsistent, and the process becomes compromised. Partially and completely plugged nozzles can

  • negatively impact the performance,
  • increase maintenance costs, and
  • lead to environmental non-compliance

Ultimately, inadequate filtration leads to partially or completely plugged nozzles, resulting in environmental compliance issues which lead to higher operating costs!

Zero Gravity Filters offers two patented separation / filtration technologies to meet the needs of the Power Generation Industry.

  • Spring Filter –The ZGF Spring Filter is a 316 stainless-steel coil wound with a variable pitch that allows the filter element to open evenly from top to bottom ensuring that all contaminants are completely removed from the filter element with each backwash.  The “nidges” provide an absolute gap to ensure consistent and reliable particle capture. The Spring Filter element is utilized in the EZ Clean family of automatic filtration systems.
  • Tornado – The Tornado is high “G”-force, centrifugal separator.  The Tornado is a simple but extremely innovative device.  The Tornado has no moving parts and no media.  Tornado effectively removes particles without any regular maintenance.

ZGF technology can be installed in a variety of processes and applications.

To get a better understanding on where ZGF technology can provide value in the Power Generation industry, click on one or more of the Process Diagram links below.  The process diagrams show you where a ZGF technology can be implemented in a specific process and the benefits it provides.


ZGF technology provides value

Utilities in Michigan, Ohio and Illinois have installed ZGF technology to the reduce operating costs and manpower requirements associated with operation of the power generating station.

ZGF Spring Filter & Tornado technologies meet all purchasing and performance criteria by effectively and efficiently capturing and removing the contaminants from the process / cooling water.

ZGF technology will provide value because it is:

  • fully automatic
  • consistent & reliable
  • non-disposable
  • energy efficient - utilizing a minimal amount of electricity and air during purge/backwash
  • able to remove particles down to 20 micron
  • able to provide value and help optimize each process by effective and efficient contaminant capture and removal
  • environmentally responsible – does not generate additional waste, unlike bags, cartridges and roll media

The product data sheets provide a detailed description and comprehensive overview of each product technology. If you want to learn more about ZGF EZ Clean or Tornado technology, then click on one of the links to download the:

Seeing is believing!

Some people need to see something in operation to really get it.  Click on the links below to see how each technology works.

  • Spring Filter animation – The animation shows the basic principle of operation.
  • Spring Filter video - See the coil open and shimmer and the contaminants disappear!
  • Phoenix animation – The animation shows the basic principle of operation.
  • Phoenix video - The narrated video explains and allows you to see how the Phoenix works; and you can see how all debris is removed during backwash when the Spring Filter opens and shimmers
  • Tornado animation – View the Tornado in operation.

Simplicity, consistency, reliability and the lowest cost of ownership make ZGF technology the best solution and value for all your filtration needs!

ZGF is your preferred partner.

 Filtration should not be a burden.

 Filtration should be a tool that improves quality and reduces cost.

Let us help you meet your objectives and make your job easier!


ZGF has the experience and dedication to customer satisfaction that you are looking for. Contact us or request a quote today.