SP 3A-FLOCCULATION PROCESS DESIGN

Design a flocculation process for a surface water treatment plant designed for turbidity

removal;

No. of parallel trains: 3, each train shall be capable of treating 1/3 of the flow

No of stages: 3

Flocculator Type: Horizontal Paddlewheel

Depth

Flow Direction

W

Train Configuration: Rectangular, as shown above

Design G values 75, 35, and 15 sec¹

Design Flow Rate (Total into Plant) = 75,000 m³/d

Gt = 75,000

Water temperature ranges from = 12°C to 22°C (you decide which will need the most power)

Max depth of water = 4 m, L shall be equal to the depth

a) Determine the hydraulic retention time for each train and stage

b) Determine the dimensions of each stage and train of the flocculation process

c) Determine the power to the water and the motor driver power for each train, assume a

mixer to water transfer efficiency of 0.75.

d) Analysis Problem: Assume that one of the trains is out of service and all the flow

must be treated by two trains. Assume the same power and dimensions (can't

change since it has been constructed). Determine the new HRT, G values for each

stage, and Gt.