Challenges High Flow Chemical Dose Controller Spring 2011
Create an improved design for nonlinear flow controller and flow measurement that will work for high flow rate AguaClara plants. The transition flow rate between linear and nonlinear flow control is not yet determined, but it is likely on the order of 100 L/s.
A new design for a High - Flow Dose Controller (HFDC) will be evaluated. This design will eliminate the use of lever-arms, pivots, slides and multiple scales. There will be only three main components to the HFDC: the constant head tank, a float and a variable orifice (e.g. valve). More information about the actual design will be included in the first Research Report.
Deadline: Order valves by February 11, 2011
Week 3: Draw basic schematic of proposed design and supply full description. Select one or two valves for evaluation. Decision to be made based on material, orifice size and desired precision.
Deadline: Initial valve evaluation and documentation by February 25, 2011
Weeks 4&5: The next two weeks will be spent evaluating the valves and documenting their flow rates at various adjustments and at various changes in elevation of the constant head tank (which may need a new name if it ends up riding on a float!). Data pertaining to the valves will be collected and analyzed and documented in the first Research Report.
Deadline: Final valve evaluation and documentation by March 11, 2011
Weeks 6&7: At this point Agua Clara will need to decide if the HFDC is a technology worth further investigation. The next step would be to select two more valves to represent a wider range of scaling. Evaluate and provide data on these valves. Stretch these limits to determine if a failure point exists. Second Research Report and Midterm Wiki are due.
Deadline: Float design and ballast system by April 1, 2011
Weeks 8 & 10: Again, checkpoint as to whether the HFDC is a viable technology. Design work on the float will begin during Week 8. The float will need to be a stable platform that can be ballasted and de-ballasted for easy field calibration.
Deadline: Initial entrance tank design April 15, 2011
Weeks 11 & 12: Considerations for implementation of the HFDC will be explored during weeks 11 & 12. Investigation of entrance tank and how entrance tank connects to the flocculator will be evaluated and designed. Part of this stage of the design is to include how plant flow rate will be measured.
Deadline: Final project and recommendations
The remainder of the semester will be utilized to tie the project together and provide solid recommendations as to whether or not this technology is well suited for AguaClara.aims to provide AguaClara plants with a simple dose controller that requires minimal input and oversight from the plant operator. In keeping with AguaClara standards, this dose controller will not require the use of electricity, will be simple to understand and operate and will be constructed from robust components. Additionally, the relationship between the driving head and flow rates within the dose controller must match the relationship between plant flow rates and water elevation in the entrance tank. The mechanism for metering flow in both the dose controller and the plant must therefore be the same and will be evaluated as part of the new dose controller design. The High Flow Dose Controller will be designed for flow rates where the Linear Dose Controller is unable to meet flow demands.