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History

Zinvent has been developing the GreenScreens for the past 10 years. These screens have been successfully deployed primarily on the West Coast from California up to Alaska to protect various juvenile salmon species from water pump suction forces. Zinvent’s proprietary screen is based on the federal and state guidelines in the Pacific Northwest regarding the various salmon juvenile species. Often these guidelines can be applied to other fish species protected by federal regulations. 

GreenScreen Advantages

Each GreenScreen design ensures necessary water flow to the pump while meeting the federal and state fish screening guidelines. Since the GreenScreen is much less likely to pull in juvenile fish species, it is also less likely to attract miscellaneous debris in the water also.


Check out the initial reviews of Zinvent's GreenScreen.   

http://www.fs.usda.gov/detail/klamath/landmanagement/resourcemanagement/?cid=stelprd3810626

Design Criteria

All GreenScreens offer a method to help ensure uniform water velocity through all screen surfaces. Each design has been flow modeled to also ensure no 'hot spots' exist that may pull in fish or excessive debris in the water.  Each design meets these criteria when properly placed in the water:

  • approach velocity - less than 0.2ft/s per the state and federal regulations (standard, but we can design for other approach velocities as needed)
  • screen hole size 3/32" or less
  • screen open area - greater than 27%
  • screen area - derived from approach velocity, flow rate calculations, and computational fluid dynamics modeling


Standard and Custom Designs

Don't see a screen that fits your application, contact us for any custom design needed. We can alter the connection type, shape, size, etc to meet your needs. 

Engineered Design

3D flow modeling of each design helps validate each screen configuration.


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Non-compliant pump screen

What is wrong with the typical screen?

The typical water intake screen attached to a pump (pictured to the left) has very little screen area to spread out the water velocity entering the screen. These water velocities easily exceed the state and federal requirements for fish screening in certain waterways. Zinvent's ClearFlow Screens meet federal and state requirements for fish screening. The additional screen area allows for a much slower water velocity at the screen face so juvenile fish can escape safety, without reducing flow into the pump. On average, a user needs ten times the screen area to get close to compliant compared to the typical intake screen. 


Often the typical screen is laying on the stream bed. This has a tendency to pull in silt, sand, mud into the pump and also blocks flow through the side that is touching the stream bed. Zinvent's ClearFlow screens have an available option to be propped up off bottom so you can pump the maximum amount of water without causing harm to your equipment and meeting the fish screening rules and regulations in certain waterways.

 

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