Vertical Flow Hydraulic Flocculator
Overview
Currently, the AguaClara team has built a new, more robust baffle system for the small scale vertical flow hydraulic flocculator that models flocculation tanks built in plants in Honduras. This new baffle system allows for faster and easier adjustments to baffle spacing and arrangement. With the ability to adjust the spacing quickly, turbidity profiles of the tank can be compared for different baffle arrangements to determine which configurations work best for different raw water turbidities and will help verify the equations used by the Design team for energy dissipation. Uniform baffle spacing and tapered spacing will be tested. In tapered flocculation the flocs are exposed to high velocity gradients in the beginning of the tank and lower gradients as they travel through the tank. The key to having reliable and pertinent results is to keep the main variable, raw water turbidity, as standard as possible, meaning that multiple tests need to be run on the same day, when turbidity is over a small range. Having an easily and quickly adjustable baffle system will allow us to run multiple configurations in a short time period, making our results directly comparable to one another.
Methods and Research
Process Controller
Process Controller is used to control plant processes such as alum dosing, turbidimeters, etc and to collect data.
Sampling Method
The method used to collect data along the flocculator.
Turbidity Profiles
In spring 2008 turbidity profiles were developed for the flocculator. Turbidity profiles are a clear way to present data regarding flocculator performance.
How to Calibrate Turbidimeters
A guide on how to calibrate turbidimeters. For accurate results, turbidimeters should be calibrated every two months.
Results
Tapered vs. Uniform Baffle Configuration
- Determine whether or not tapered flocculation is more efficient than uniform flocculation.
- Determine the optimal alum dose for the flocculator
Turbidity Profiles for the Tapered Flocculator
- Find the optimal alum dose on the day of testing and running the Profile Test and develop and implemented a procedure to determine the turbidity profile.
Testing of Uniform Baffle Configuration
- Determine the turbidity profile for the Uniform Baffle Configuration.
- Develop a grab sample method to test the accuracy of the turbidimeters.
Construction History
Testing and Tank Modifications
Construction of Tapered Baffles
Construction of Adjustable Baffle System
Design
Flocculator Methods and Maintenance
Flocculator Maintenance Procedures