StaRS Filter Injection and Extraction (FInE)

StaRS Filter Injection and Extraction (FInE)

The AguaClara StaRS (Stacked Rapid Sand) filter originally used slotted pipes to inject water into and extract water out of the sand bed. These slots can gradually clog especially if the water from the sedimentation tanks isn’t very clean. The goals for this team are to explore and invent alternatives to slotted pipes that would be less prone to clogging.

Fall 2015

The goals for the Fall 2015 FInE Team are to complete fabrication and commence testing of the proposed extraction unit. The new extraction unit is a PVC pipe with orifices along the sides of the pipe and wings extending tangentially from the top. The major concerns with this system are whether or not the gravity-based sand exclusion zones still exist below the wings and whether or not backwash initiation will drive sand into the extraction unit, thus reducing the filtering capability of the FInE system. 

Spring 2015

The team faced the problems of clogging of slotted pipes, fluidization of sand and need for larger holes of new sand exclusion. The team has successfully worked on optimizing wing design and changed the inlet pipe by replacing the wings with only orifice design after several trials of vertical wings on inlet pipe. For the outlet pipe, the capped system has been tested and improved backwash fluidization movement. Still, further work, including accomplishing fabrication and testing outlet pipe with cap on the top, needs to be continued.

Fall 2014

Under the name of "Alternative Backwash without Slotted Pipes," this team was the precursor to the current FInE team. This team began the process of designing and fabricating an alternative to slotted pipes for backwash and filtration. The team built a model of the StaRS filter for testing purposes, and tested several different options for inlet and outlet valves. First, the team tried a rectangular prism cut in half, facing downwards. This design had performance and practicality issues, so the team created an alternative design, which was a hollow cylinder with protective wings extending from the sides and a row of holes in the bottom of the cylinder. Unfortunately, sand was still entering the pipes with this design, so the challenge was passed on to the Spring 2015 team.