The capacity of the tunnel(s) is usually kept at about 20% of the
canal discharge, and they are designed to maintain a minimum velocity of
2–3 m s^1 (to avoid deposition in tunnels).
(b) Silt ejector or extractor
The silt ejector is a device constructed on the canal downstream of the
head regulator but upstream of the settling basin (if any), by which the silt,
after it has entered the canal, is extracted.
- Vane type ejector.The layout of a vane type ejector is shown in Fig.
9.22. A diaphragm at the canal bed separates the top layers from the
398 DIVERSION WORKS
Fig. 9.22 Silt ejector (vane type)
