Question

A rectangular settling tank is being designed to settle sand particles that have a settling velocity of 2.0 cm/s. The water flow is 10,000 m3/d. The tank length should be four times the width and the width is equal to the depth. Please find the dimensions for the tank in meter.

Answer 1

Answer:

b = 1.2 m

L = 4.8 m

d= 1.2 m

Explanation:

Lets take

Width of the tank = b

Depth = d

length = L

Given that L = 4 b

v= 2 cm/s

Flow rate Q= 10,000 m³/d

We know that 1 d = 24 hr = 24 x 3600 s

1 d= 86400 s

Q= 0.115  m³/s

Flow rate Q

Q= Area x velocity

Q= L . b .v

0.115 = 4 b . b . 0.02

4 b² = 5.78  

b = 1.2 m

L = 4.8 m

d= 1.2 m

This is the dimension of the tank.