2.1 Design of Pumping Machinery at Intake Structure

Design Flow (Q) = 18 MGD

Add 5 % losses due to backwashing and
underflows from the sedimentation tank = 0.9

Total Design Flow = 18.9 MGD
Working Hours = 18

Design of Pumping Machinery for Ph I & II

Since the project is to be developed in three phases and Ph I & II will be developed under the ongoing scheme, therefore pumps requirement has been worked out separately for Ph I & II and for Ph III separately.

Demand of Ph I & II inclusive of 5 % losses = 12.6 MGD
Working Hours = 18
Total Design Flow = 12.6 x 1000000 / 6.24 x 18 x 3600
= 31.20 Cusecs
Capacity of proposed Pumps = 6.0 Cusecs
No of Pumps = 5.20

It is proposed to install 6 Pumps (5 working, 1 standby) each of 6.0 Cusecs capacity.

Design of Pumping Machinery for Ph III

Calculations of pump requirements for Ph III are as follows:

Demand of Ph III inclusive of treatment losses of 5 % = 6.3 MGD
Working Hours = 18
Total Design Flow = 6.3 x 1000000 / 6.24 x 18 x 3600
= 15.58 Cusecs
Proposed capacity of each pump = 6.0 Cusecs
No of pumps required for Ph III = 15.58 /6.0
= 2.60

It is proposed to install 4 Pumps (2 working, 1 standby) each of 6.0 cusecs capacity.

In the light of above calculations, it is proposed to build a Pump House that can accommodate 9
Pumps each of 6.0 Cusecs capacity. Under the present scheme of development 6 pumps will be installed whereas space will be allocated for the installation of additional 3 pumps under Ph III in future.