Water TreatmentPackage Plant Design

Sedimentation TankDesign

1 of 4

Sedimentation Tank design

Typical design criteria for horizontal-flow rectangular tanks with tube settlers

MWH pp.823

"Tube settlers typically have detention time less than 20min, but they still have a settling efficientycomparable to that of a rectangular settling tank with a minimum 2h detention time."

Water TreatmentPackage Plant Design

Sedimentation TankDesign

2 of 4

General Data

Raw water, Q = m3/s

Number of basin = No.

Unit Load = m3/s

Adopted Parameters

Settling Zone Dimension by trial and error

Width W = m AssumedDepth D = m AssumedLength L = m Assumed

Settling Area, A= m2Vf Ɵ = m/sVf Ɵ = m/h < 2.5 to 6.25 m/h

Total TankWidth W = m

0.0289

2

1.21

0.01447

2.4

2.880.0164859.3303

1.22.4

Width W = mDepth D = mTotal Length L = m

Tank volume, V = m3 including additional % for settling.Thus, Total length = m

Detention time, T = s= 10 min OK

Tube settlers

Length Lp = mWidth d = m

Settling Velocity, Vs = m/s AssumedƟ = 60 degrees

3

0.7

8.64

597

0.00061

0.05

25

1.22.43