2.2 Design of Rising Mian

Rising Main from Raw Water Pump Station to Reception Tank of the Water Treatment Plant shall be designed to cater for the requirement of Ph I, II & III.

Design Flow for Rising Main = 18.9 x 1000000 / 6.24 x 18 x 3600
= 46.74 Cusecs

Length of pipe = 400.00 Ft

Dia of Pipe = 36 “
(Pipe has been designed to carry 18.9 mgd flow)

X - Sectional Area of Pipe = 7.065 Sft
Velocity = 46.74 / 7.065
(Velocity has been worked out for 18 mgd flow)
= 6.61 Ft /s

Head Loss in Pipe = 4 x .01 x 400 x 6.612 2 2 x 32.2 x 3.0
= 3.61 Ft

Add 10 % head loss due to bends & specials = 1.0 Ft

Total Headloss due to friction = 4.61 (Say 6.0 Ft)

Suction Lift of Pump (987 - 966) = 21.0 Ft

Full Supply Level (FSL) in the Stilling Basin is 979.0 and water will be drawn in to the sump of the Pump Station from the bottom of the basin at a level of 966.0 by laying three inlet pipes. Under normal conditions when the Khari Canal is flowing full, water level in the sump will remain at 979.00. However, under acute dry conditions when the channel is not flowing, water stored in the Stilling Basin will be utilized. Under the extreme dry conditions water level in the Stilling Basin will be reduced to extreme low i.e 966.0. Raw water pumps have been designed to cater for this extreme condition.

Difference of G.L between Intake Structure &
Reception Sump of Treatment Plant (1042.88-987) = 55.88 Ft
Head Loss in the Rising Main = 6.0 Ft
Suction Lift = 21.0 Ft
Total Head = 82.88 Ft

Say = 90 Ft

Electrical Horse Power of proposed pumps =62.4x6x90x.746/550x 0.65
= 70.31 Kw
= 75.0 Kw (Say)