|
 Passive
intake screens, for the withdrawal of large volumes of water from streams,
lakes/reservoirs is a very important segment of the products designed and
manufactured by Hendrick Screen Company.
What Is Passive Screening?
Passive screening admits water through the intake point at a low, uniform
velocity. Water passes through the screen while aquatic life and debris
remain in the water source. The screens have no moving parts, therefore
the term “passive screening”. The screens can be placed away from the
shoreline for better water quality and distant from high concentrations of
debris and marine life.
Advantages of Hendrick
Passive Screening
Passive water intake screens offer these Advantages:
 | Reliable water delivery |
| Lower screen cost |
| Simple intake and pump station design |
| Lower maintenance cost |
| Very low slot velocity and uniform flow. |
| Environmentally fish friendly |
| Bio-fouling resistant screen material |
Keeping A Passive Hendrick
Intake Screen Clean
Installing an intake screen at the proper depth, distance from the
shoreline and proper distance from each other is a crucial step in
avoiding clogging debris. Proper screen design is another. A Hendrick
intake screen minimizes plugging problems with a perforated core tube that
provides very low velocity uniform flow. Potentially plugging
materials are not held against the screen surface.
In high debris environments, debris removal is achieved
with the installation of a Hendrick airburst system. Debris is carried up
and away from the screen surface with a rapid release of air through
manifold of nozzles designed into the intake system.
Other design considerations will also determine whether
or not a passive intake screen will remain free of debris. These factors
include:
| The screens proximity to the water surface |
| The proximity of screens to one another |
| Additional structures required to protect the screen |
| Support of screens in the water |
| The location of the air connection |
| The use of screens in multiple-level withdrawal |
| Rail systems for easy screen removal |
| The use and placement of a chemical feed line |
| Space requirements for airburst systems |
| Water temperature and ice formation |
Intake
Screen Sizing Spreadsheet
See the Engineering
Section for Sample Engineering Specifications & Documents |
