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In Fall 2007, the team investigated the effect of introducing obstacles into the flow. Currently, the only sources of shear (and thus mixing and flocculation) are the 180° bends between the vertical flow channels. In the channels between those bends, there is very little shear - it is similar to pipe flow. There is therefore a large variance between the maximum shear (at the bends) and the average shear. That means the plant is The flocculator is not as space-time efficient as it can be. By introducing suitable obstacles (that create shear and mixing) into the vertical channels, the average shear is increased significantly without increasing the maximum shear. The results of the experiments were mixed and inconclusive. While theoretically, the obstacles should improve the performance of the plant, the actual results did not show those trends. Many parameters, some of which are still unidentified, affect the performance of the plant. The team has yet to determine the limiting factors and the problems with the experiments.
In Spring 2008, the team went "back to basics" to redesign the demo plant, and to characterize the performance of the demo plant without introducing obstacles. Aside from the plant to be built for demonstration only, the team also built a plant for experimentation. It is hoped that the results of the performance tests will shed some light on the limitations of the plant and thus help explain the results of the experiments done last semester.
Spring 2008 Experiments
- Determining Flocculation Efficiency
In order to redesign the Demo Plant, the team needed to determine the flocculation efficiency factor, which accounts for the fact that not every collision between particles sticks.
- Performance Tests
Experiments were performed on the new plant to characterize its performance. The detailed description and results of the experiments can be found in this section.
Fall 2007 Experiments
- Introducing Obstacles
The Demo Plant team experimented with introducing obstacles into the flocculator. The detailed descriptions and results of these experiments can be found in this reportFall 2007 report.
Spring 2008 Experiments
The team redesigned the demo plant in Spring 2008. Additionally, the following experiments were performed:
General Demo Plant Instructions
- Process Controller Instructions
Instructions on how to set up the process controller program for lab set up of the demo plant - Experiments were performed on the new plant to characterize its performance. The detailed description and results of the experiments can be found here.
- Determining Flocculation Efficiency