Inlet Manifold Research Team
Introduction
The design challenge for the Inlet Manifold Research Team is to design an inlet manifold for the sedimentation tank that meets the following constraints:
- Maintain the velocity of the water high enough to prevent sedimentation prior to the tank
- Obtain an even distribution of the influent along the length of the sedimentation tank
- re-suspend the flocs in the bottom of the sedimentation tanks to promote a floc blanket
- prevent floc breakup
- test the theories of manifold flow and the effects of pressure recovery
The inlet manifold consists of a PVC pipe with a row of drilled holes facing down. The jets coming out of the ports will prevent floc accumulation in the bottom of the sedimentation tanks and hopefully the velocity will keep the floc in suspension to create a floc blanket.
Read more about the inlet manifold design. If you are new to the project, please check out the current challenges. Included are our team's [detailed task lists] for further information.
Manifold Theory
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Figure 1: Hydraulic Gradeline and Energy Gradeline profiles for an Inlet Manifold
By looking at this image on the right, we can observe that as the water runs through the manifold, the Hydraulic Grade Line (HGL) decreases due to major head losses (friction losses along the pipe walls). But, as the water passes each port and the flow inside the manifold decreases, the velocity inside the manifold decreases as well. As a consequence we should observe a decrease in the HGL slope after each port.
But the most interesting aspect of this study, is that as the velocity decreases we will have a pressure increase after each port (refer to eq-1 on theoretical information about manifolds), which leads to an HGL increase, if we keep the elevation constant, as is the case.
This is what we call pressure recovery!
Considering the major head loss along the manifold is small, due to the low velocities we have to prevent floc breakup,these local HGL increases will have a big impact in the overall HGL shape and we expect to have a higher HGL at the end of the manifold than at the beginning, and therefore a higher flow in the last ports.
Stay up-to-date on this project by checking
the Meeting Minutes, [goals] and Challenges for Future Semesters.
Current Research Teams
Spring 2010 Inlet Manifold Research Team
- Redesigning the inlet manifold for the sedimentation tank in an effort to maintain constant flow out of all of the ports.
- Measuring energy dissipation in a model flocculator using particle image velocimery.