Wedge Wire Water Intake Design Considerations

When designing an intake system, the water intake screen is a critical element to a well-designed system. The entire water intake system is dependent on the functionality of the water intake screen in order to work correctly. If the screen is designed properly, it leads to an efficient system that will reduce maintenance costs over the system’s lifespan. However, cost savings isn’t the only consideration to a good design.

Key qualities of a properly designed water intake system:

1.Meets the requirements of the operating environment

2.Provides operational efficiency

3.Minimizes head loss in the intake system

4.Meets EPA 316(b) requirements

5.Protects aquatic life

There are several different types of intake screens on the market. Knowing the types of screens and their benefits can help you design the most efficient system. The three most common are:

- Drum Screen: Drum screens are used in quiet waters where the water current passing the screen is minimal. This would include lakes and reservoirs where water conditions are stable and have a low velocity water flow. Drum screens are also ideal for tight spacing conditions. The screens can be mounted vertically or horizontally to prevent debris from collecting on the screened surface. The drum screen is also the most economical form of intakes.

- T-intake Screen: The most common installation is for a T-intake screen. They are often designed for cooling plants, pulp and paper mills, and other industrial facilities that require the intake of large amounts of water from lakes, rivers or oceans. T-intakes are designed to withstand multiple water conditions including the harshest environments. Screen manufacturers offer flexibility in the design of the T-intake to accommodate special conditions where the unit will be installed. For example, the intake screen can be designed with a conical end to deflect debris that flows toward it (also see Early Involvement of the Screen Manufacturer).

- Half-Barrel Screen: The half-barrel screen is designed for shallow water conditions, it provides the same screen flow characteristics as a larger T-intake screen. However, its half-size allows it to be placed on the bottom of streams and rivers where a T-intake wouldn’t work.