Angled Sieving Experiment

By Amy Kerrison

The group started off the new year by getting some more testing done, including the first of the angled sieving tests. Since the nurdle sand flow rate is currently unknown we treated these tests as a proof of concept to test the rig and judge if there was any promise for the system in future.

Currently keeping the mesh static (no vibrations) we poured a 180g:20g sand: nurdle mixture onto the top of the mesh to see if the sand will pass through leaving the nurdles to slide down to be collected. These tests were very promising, providing some good data to justify further experiments. A video of one of the tests is shown below.

The optimum angle found was between 20-30 degrees; lower and the nurdles didn’t slide down the mesh and higher closed off the mesh opening too much, so the sand was collecting with the nurdles at the bottom.

The photo below on the left shows the collection at 30 degrees, and the photo on the right is at 45 degrees.

Further tests are being planned to introduce different frequencies of vibrations at the optimal angle to see if that improves the efficiency of collection/separation. These values will then be used for tests with wet sand which has been a large obstacle in our project so far.

We are looking forward to wrapping up our lab testing in the coming weeks and starting to collate our results to optimise our final design.