Tennessee Wastewater Operator Practice Exam

What screening method is characterized by having a rectangular opening?

1. Perforated plate screen

2. Continuous self-cleaning screen

3. Catenary screen

4. Manual bar screen

The correct answer is: Continuous self-cleaning screen

The screening method characterized by having a rectangular opening is the continuous self-cleaning screen. This type of screen is designed to filter out solids from wastewater by using a series of angled screens with rectangular openings. The rectangular shape allows for effective screening of various sizes of particles, improving the efficiency of the screening process. Continuous self-cleaning screens often incorporate mechanisms to remove collected debris automatically, which helps maintain the flow and reduce maintenance needs. This feature is advantageous in high-flow situations where manual cleaning would be impractical and labor-intensive. The other methods, while effective in their own rights, do not primarily utilize rectangular openings. Perforated plate screens typically have holes that may be circular or another shape rather than rectangular. Catenary screens usually employ a different configuration that focuses on the design of the screen surface and flow dynamics rather than the shape of openings. Manual bar screens utilize bars that have gaps but are not structured with rectangular openings, as the spacing is generally fixed.