*** This version of Confluence is for testing only and contains a copy of content from June 29th 2026. No changes will be preserved. ***
...
The purpose of this experiment is to determine the optimal plate settler spacing using tube settlers and a tube flocculatorand by exploring the limiting design parameters. The goal is to consistently produce effluent water with an effluent turbidity of less than 1 NTU.
Methods
The experimental apparatus is designed to be as robust as possible allowing for various experiments to be conducted using the same setup. The setup is made up of three unit processes, the constant turbidity control, flocculation, and settling column. Our focus for the experiment is on the settling column, where we will be varying certain parameters. We optimized the turbidity control system and the flocculator to create ideal conditions for floc blanket formation and sedimentation in the settling column.
...
Design Parameters (parameters/equations/length and diameter values/critical settling velocity values)
The use of a tube flocculator allows for a more controlled flocculation environment as compared to flocculation with baffles. The flocculation design parameters are based on creating optimal conditions for floc blanket formation. For this experimental apparatus the flocculator is 17 m and the inner tube diameter is 3/8 in (see table). The average velocity gradient for the flocculator (G) is 71.4 s-1 , the residence time (θ) is 125.4 s and the G θ is 8.959*103.
These values are found using the following equations:
Average Velocity Gradient
Residence Time
The high G value and long residence time helps create the large amount of flocs needed for the initial formation of the floc blanket.
Based on the allowable space in the settling column the floc blanket height will be 50 cm.
Uniform Flow
Uniform flow in the settling column is key for having laminar flow in the tube settlers as well as the creation of the floc blanket. As seen in the image to the right, a uniform flow is needed at the inlet of the settling tube so the flow becomes laminar before reaching the end of the tube. All design assumptions and parameters for the column are based on a laminar flow through the settling tubes.
...