Outside-flow drum screens — a rotating drum where water passes from the outside to the inside, trapping debris on the outer mesh; used at space-limited coastal intakes that benefit from outer-surface capture.
Intake Screening for Water & Desalination Plants
An outside-flow drum screen rotates about a horizontal axis with water passing from the outside of the drum to the inside, trapping debris on the outer mesh which is spray- or air-washed off at the crown. Less common than through-flow drums in desalination, it suits space-limited coastal intakes that benefit from outer-surface capture and continuous, low-head self-cleaning.
Rotating drum, outside-to-inside
Partially-submerged mesh cylinder turning on a horizontal axis.
Debris captured on the outer surface and lifted clear.
Crown wash removes the captured mat each revolution.
Large area gives very low through-mesh velocity.
Low approach velocity protects aquatic life.
1–10 mm mesh to suit debris and fish duty.
| Parameter | Typical | Notes |
|---|---|---|
| Flow path | Outside-to-inside | Debris on outer mesh |
| Head loss | Very low | Large screen area |
| Cleaning | Spray / air wash | Continuous, at crown |
| Mesh | 1–10 mm | Debris & fish duty |
| Use | Space-limited coastal intakes | Where outer capture is preferred |
Continue across the screening knowledge base
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