...
The purpose of this experiment is to determine the optimal plate settler spacing using tube settlers and a tube flocflocculator.
Methods
The experimental apparatus was 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 an ideal conditions for floc blanket formation and sedimentation in the settling column.
...
Design Parameters (parameters/equations/length and diameter values/critical settling velocity values)
Uniform Flow
We want uniform upward flow so flow through tube settlers is laminar
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.
Flow in to the system from the bottom of the settling column creates a jet in the center of the column, which is far from uniform flow. A typical Cone
Typical jet dissipation ratio is 1:10
Ratio of cone diffuser 4:6
Mesh
Break up inlet jet into several
weaker jets ; therefore, it would take on the order of 10 m for jet to dissipate in a column with a diameter 10 cm, as in the current setup. A cone with a ratio of 4:6 is used a diffuse to maximize the lateral spread of the jet. In addition to the cone, there is a mesh directly on top of the cone made of a 1 cm thick plastic sheet with uniformly distributed holes of 0.5 cm diameter. This mesh will break up the single jet coming from the column inlet, into several smaller, weaker jets that will dissipate quicker. The preliminary stages of the experiment will test the effectiveness of the cone and mesh system in dissipating the jet and allowing for optimal floc blanket formation.
Results and Discussion
Obstacles
...