Page History

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• Steve Mitchell
• Julia Schoen
• Henry Zeng

Challenges

Linear

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Chemical Dose Controller

• Test if the pipe is sized too small to accommodate the flow rate which the orifice pattern is designed to deliver and if the LFOM will fail for all flow rates. This hypothesis could be easily tested by using the momentum approach to determine the maximum flow rate out of the bottom of the LFOM for all water depths. This should be tested by doing the analysis in MathCAD. Henry and Steve February 14th

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• Reassess all of the tubing connections and mechanical design of the dose controller to see if there are improved fabrications techniques that would make the whole system work better.
  • Set up linear CD system (like the one in Tamara) in the lab: Henry and Steve, Feb. 20th
    • Order parts
    • Set-up a meeting with Nicole once it's finally set-up
  • Communicate with APP to figure out how the prototype is working: Nadia, Feb. 15th
  • Experimentally, determine how small the chemical doser vertical drop tubing can be before the open channel flow or free fall fails. Henry and Steve, Feb. 27th
    • Obtain various tubing diameters and test them
    • The size of the open channel flow tube controls the change in the mass of water held by the lever system. This determines the minimum size of the float that will provide a reasonably small dosing error. The size of the float and the length and angle of the lever determines the amount of horizontal motion that the float has. And that determines the minimum size of a small float tank that could be used. We might replace the controller float tank with a large PVC pipe that has a tiny tube connected to its side.
  • For example, it would be possible to eliminate the Guest Fittings and use a hole drilled in a half inch PVC pipe (the open channel flow pipe) to connect the ¼" OD tube from the flow controller to the open channel flow pipe.
  • Test any ideas that arise as we are building the system.

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Nonlinear Chemical Dose Controller

• Design a dose controller that will work for chemical flow rates in excess of 400 mL/min. This dose controller would use orifice flow in the entrance tank flow meter and in the flow controller. The design could be used at the Gracias plant.
  • Sketch Ideas: Julia and Nadia, Feb. 20th
    • Issues: Headloss through float valve restrictive. We must focus on the minor losses instead of the major losses.
  • Build: Julia and Nadia, Feb. 27th
  • Test: Julia and Nadia, Feb. 29 - March 11th
  • Document the design: Julia and Nadia, March 25th

Linear Chemical Dose Controller Paper

• Write an initial draft of paper for the Journal of Water Supply: Research and Technology (AQUA) documenting the design and performance of the dose controller. Henry, March 7th

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• Midterm Wiki Report: All, March 13th

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MathCAD

• Compile Mathcad MathCAD files from CD, LFOM, and FC into one APIS file and then show the rest of the team how the code works. Steve, Feb. 17th
• Add a float size algorithm to the current CD Mathcad file: Steve, Feb. 20th
• Use mathcad to determine what size of a float valve is needed to handle flows in excess of 400 ml/min. Steve, Feb. 20th

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• Follow up: All, By end of semester miscellaneous
  • Create descriptive sketches/animations that will go into the journal article. Also, consider the need for documentation for our future partners: Ecuador and Pakistan.
  • Find a way to effectively provide APIS CDC designs to these new partners
  • Integrate our designs with the Design Team's code

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