Sanitary Engineering

Lecture 14

Manhole cover

gutter example

gutter example

Wastewater Pump Station

Example:For flow rate 18000 m3 /d , design wastewater pump station ,consider the dry part = 40% and wet part = 60%.

-------------------------------------------------------------------------------------------Qave = 18000 m3 / dQmax = 2 Qave = 36000 m3 / dD.T. = 15 minVol = Q * D.T. = {3600 / (24 * 60)}* 15 = 375 m3. Depth = 4.00 mArea of wet well = Vol / depth = 94 m2

Dry well = 40%Wet well = 60% wet area / Total aerea = 60 / 100Total area = Wet area *100 / 60 = 94 / 0.6 = 157 m2

D = 14.15 m.   

Design of rising pipe: Q = 375 / 15 * 60 = 0.417 m3 / secNo . of units = 2

q = Q / 2 = 0.209 m3 / sec. Velocity = 1.1 m / sec .Diameter = 50 cm. = 20 inch.Transport pipe = 70 cm. = 28 inch.