A concrete trunck sewer with a diameter of 075 m is designed

A concrete trunck sewer with a diameter of 0.75 m is designed to carry the sewage from a proposed collection system. If a minimum cleaning velocity of 0.75 m/sec is to be maintained and the interior surface of the pipe is in good condition a) What is the maximum flow rate that the sewer can carry? b) At what slope should the sewer be laid in order to insure self cleaning at all times? c) Given that the minimum flow rate is one third of the maximum flow rate, what is the minimum depth of the flow?

Solution

Solution:-

Given

Self cleaning velocity (V) = 0.75 m/s

Diameter of sewer(D) = 0.75 m

(a)   Maximum flow rate (Q) = A*V

= /4 *D²*0.75

= /4 * (0.75)² *0.75

= 0.33 m³/s   Answer

(b) Answer:- Slope for self cleaning velocity are 30 degree to 37.5 degree .

(c) Solution:-

Given

Q_mini = Q_max/3

A_mini *V = (A_max *V)/3

/4 *d² = (/4* D²)/3

d = 1/3 *(0.75)

Minimum depth of flow(d) = 0.433 meter    Answer