"Lishan Zhu"'s Individual Contribution Page

"Fall 2013" Contributions

I joined Aguaclara in the spring semester of 2013. Last semester, I worked on the foam filtration team. This semester, my team members Alexandra Green, Sarah Sinclair, Chris Wen, and Jeanette Liu and I are working on the Low Flow Stacked Rapid Sand filter (LFSRSF). 

In the fall semester, I joined the 12in. subteam that is responsible for creating the new filter along with my teammates Sarah Sinclair and Chenxi Wen. This semester, we have designed a created a filter column that can be used to test and make improvements on a design that was used in India.

A large challenge we faced with designing the filter was how the slotted manifolds, inflow, and outflow tubing would be installed with the constraint of only being able to reach arm's length. This created the solution of cutting the main filter column into two pieces, but we then needed a plan to securely join the two halves of the filter column with a leak-proof seal. By the end of the semester, we successfully devised a system that involves joining the two columns with a Fernco coupling gasket, surrounded by shim stock for support, and tightened together with two hose clamps. This method of construction will join both the filter column in the middle and attach the PVC sheet caps to the top and bottom of the filter column.

The next step the team took to complete the new filter was deciding what kind and size of PVC piping would be optimal for the filter we were about to build. When we were designing the connection between the inlet tank and inlet piping, our subteam realized using flexible clear PVC piping would eradicate the problem of the complex geometry involved with connecting rigid PVC pipes from the inlet to outlet tanks. After consulting Professor Weber-Shirk and Julia Morris of the design team about the existing stacked rapid sand filter Mathcad file, my team and I decided that a  1 in. inner diameter flexible PVC tubing would be best for the intended design. 

A non-leaking entrance and exit tank have preliminarily been designed using a 6 in. PVC pipe with PVC sheet caps to form the bottom of the "tank." The team is still working to test the water containing abilities of the system. The final design of the inlet and outlet tanks and the effluent waste pipes will be tackled by next semester's Low Flow Stacked Rapid San Filter team. Also, the manifold calculations and method of installing the slotted manifolds will also be designed by next semester's team.