QUESTION
Objective Question
The self cleaning velocity of waste water flowing through sewer should be
Answer
( Option B)
A minimum velocity maintained at 0.45 m/s at minimum flow
Solution
(i) Self cleaning velocity is the minimum velocity at which no solid gets deposited at the bottom of sewer.
|
S.No. |
Minimum velocity |
Type of flow |
|
1. |
0.8 m/sec |
Design peak flow |
|
2. |
0.6 m/sec |
Current peak flow |
|
3. |
0.45 m/sec |
Minimum flow |
(ii) Maximum velocity To avoid erosion of pipe surface maximum velocity should be limited as follows
Concrete sewer → 2.5 - 3 m/sec
Cast iron sewer → 3.5-4.5 m/sec
Stone ware sewer → 3-4 m/sec
