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 / d Qmax = 2 Qave = 36000 m3 / d D.T. = 15 min Vol = Q * D.T. = {3600 / (24 * 60)}* 15 = 375 m3. Depth = 4.00 m Area of wet well = Vol / depth = 94 m2 Dry well = 40% Wet well = 60% wet area / Total aerea = 60 / 100 Total 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 / sec No Design of rising pipe : Q = 375 / 15 * 60 = 0.417 m3 / sec No . 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.