Tapered vs. Uniform Baffle Configuration
Abstract
The vertical flow hydraulic flocculator has been used to test tapered and uniform baffle configurations during previous semesters, but the two configurations have never been compared with similar raw water conditions. For this reason the Fall 2008 Pilot Plant Flocculation team focused on determining which flocculation configuration is optimal. The tapered flocculation configuration model is based on the G-theta Model, while uniform configuration is based on the energy dissipation model. In our final results, the tapered baffle configuration produced marginally better turbidity than the uniform baffle configuration. However, due to low temperature conditions, the incoming turbidity was too low in order to produce conclusive results.
Introduction and Objectives
Recently development in Aguaclara technology have shown that the Gtheta model may be inappropriate to describe flocculation. A main goal of the pilot plant flocculation team was to determine the optimal flocculation configuration: Tapered or Uniform Baffle Spacing. Using the Gtheta model a tapered configuration would expose flocs to high shear initially and as flocs grew they would be exposed to less shear. Using an energy dissipation model the uniform configuration would be optimal. The tapered flocculator
The Pilot Plant flocculation team approached this problem by first determining the optimal spacing for the tapered flocculation configuration. It was then determined that the two configurations would only be comparable if the uniform spacing was equal to the last section of the tapered spacing. The tapered and uniform spacings were compared consecutively. The tests were then run in the same day to ensure similar environmental conditions and comparable data.
An important aspect of the vertical flow hydraulic flocculator is the alum dosing One of the main issues of this semester was determining appropriate alum dosing in the cold. This problem was approached by inquiring the staff at the Water Filtration Plant about their Polyaluminum Chloride dosing. Their dosage was then converted so that the Pilot Plant can insure proper dosage with a simple equation based on the plant's dosage.