Challenges for Spring 2010

Subteam Leader: Karen Swetland

Number of team members needed: 5-6 total

Important team member skills:

• MathCAD
• Fluid Mechanics
• AutoCAD
• Vendor Purchasing and Relations
• Process Controller

Challenges

Though much progress has been made in the development of a reliable and fully-functional nonlinear chemical dose controller, many challenges still remain. On the whole, the current designs need to be validated by various experiments.

Orifice Sizing and Dual Scale

The dual scales on the lever arm currently do not include major head loss in the dosing tubes. The team will investigate the effect this head loss could have on dosing accuracy. Ensure that major head losses are insignificant to some percent error and will not have a large effect on the total head loss for all flow rates.

Rapid Mix Tube

• Collaborate with the tube floc team.

• Utilize the newly designed system to eliminate the pulse dosing of the peristaltic pumps to test the hypothesis that pulse dosing could create pockets of dirty water that could go through the flocculator.

• Design ways to effectively incorporate different designs of a scaled down rapid mix section for FReTA. With the final design of the system, try to make a system where different residence time and energy dissipation rates can be tested in rapid mix.

• Measure the potential impact of poor macroscale mixing by adding approximately 10% of the turbidity AFTER the rapid mix process. Possibly compare the effect that different energy dissipation rates and residence times in both flocculation and rapid mix can have on floc's ability to sweep up residual turbidity.

Float Sizing

Investigate the feasability of adding a counterweight to the slider assembly. Run a control experiment without a counterweight and compare to having a counterweight added. Note the feasability and reliability of having an operator use a counter weight on the slider.

Prototype Frame

Subsequent iterations and design changes will be made to the prototype frame, one version of which has been installed in Agalteca.

Orifice Clogging

The clogging experiment is the first step in ensuring that the orifice sizes we designed are feasible for the given alum doses. Further clogging experiments will be done to reproduce the results and isolate the cause of the clogs. Continue to run the orifice clogging experiment. Potentially look at varying the chemical composition of the water, i.e. starting with a low alkalinity water to a high alkalinity water to see if this has any effect on how long it takes to clog. Try utilizing different sizes of orifices to gather more data on how long it takes to clog. A smaller diameter orifice could potentially clog more quickly and give us a better idea of the range of orifices that could work that would eliminate most clogging.

Prepare for EPA Competition

Finalize much of the experiments and design with any subsequent iterations before March so that the team can prepare the required material to present.