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# Settling Basin Design

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Settling Basin Design

Settling Basin

Drawing water through the intake, its is not possible to
extract clear water only, certain percentage of bed
with water.
If the water along with sediment enter into the turbine,
it will cause damage to the turbine due to abrasion.
Therefore, its very necessary to supply as much clear
water into the turbine.
In order to exclude the sediment settling basin are
provided in the water conveyance system.
Settling basin is a wider section in the water
conveyence system that decrease the velocity and
allow the sediment to settle.
Width and length of the settling basin is based on the
required size of the sediment to settle.

Types of settling basin

Periodic Flushing type
Continuous Flushing Type
Intermittent Flushing Type

Periodic Flushing type

It has to be drained completely for the
flushing.
After draining, 10% of the design discharge is
used for the flushing of the settled sediments.
Effect the power plant operation

Continuous Flushing Type

Continuous Flushing Type

The Bieri Settling basin ensures energy
production even during the flushing procedure.
The sediments which settle in the settling
basin are flushed vertically through the
opening into the flushing channel and back to
the river.
The flushing water volume is therefore kept to
a minimum.
Sensors permit fully automatic operation.

Intermittent Flushing Type

A special conduit filled with water can
float and drawn and may close and
open the slot of flushing channel.
Modified form of continuous flushing
type

Design parameters for
Silting

Fall Velocity
Concentration of flow

Fall Velocity
Fall velocity is average terminal
velocity of a particle falling in quiscent
distilled water of infinite extent.
It depends upon
1.Shape and size of the particle
2.Weight of the particles
3.viscosity

Fall Velocity
Settling velocity formula:
ω = [4*g*d*Δ/3*Cd]1/2
where
Cd =Drag Coefficient = 24/Re =
Δ=
d = diameter of settling particle

Concentration of flow

## Recommended

#### Settling Ponds

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