Team:Exeter/Hydrocyclone
The Filter: Stage 1 - Hydrocyclone
Hydrocyclone 1
For the second design, I wanted to learn to use the software package Autodesk Fusion 360. I decided to use Autodesk Fusion 360, as it is free for students and is extremely intuitive for beginners. After getting to grips with the software, I generated a design specifically created for 13mm piping which we have in the labs. The design was quite simply influenced by the shapes of other hydrocyclones seen on the internet. Unfortunately, the 3D printer printed support structures on the interior of the hydrocyclone which were impossible to remove (note to self, always check where the printer will print support structures). Thankfully, I did learn from this model that the inlets were marginally too small for the piping and I was afraid of leakages, so I went away and made the design slightly larger in order to ensure a tight fit. To prevent the support structures from affecting the interior of the cyclone, I split the design into four seperate components which I plan to glue together using Loctite Ultra Control Gel. I chose to use Loctite Ultra Control Gel following some brief research into the most effective adhesives for PLA plastic. Ideally, I would have used a 3D printer that can print dissolvable, PVA support structures so I could have printed the hydrocyclone as a single piece.
After gluing together the hydrocyclone - which went exactly as I had planned, thankfully - I realised that to achieve the desired vortex I needed a more powerful pump than the peristaltic pump we have in the labs. My initial idea was to source a pond pump from an aquatics supplier, however to achieve the desired 800ml/s (approximately), I would need a pump that would cost somewhere in the region of £120. Unfortunately this meant that the hydrocyclone was pretty much useless. The only testing I was feasibly able to accomplish was running a tap through the cyclone to explore whether the volume of underflow still vastly exceeded the volume of overflow. Literature suggests that the ratio of overflow to underflow should be approximately 80:20. Annoyingly, the overflow:underflow ratio was closer to 20:80 with this cyclone. Because of this minor set back, I went back to the drawing board to work on Hydrocyclone 2.
Hydrocyclone 2
Design adaptations
After stumbling across a paper titled The Sizing and Selection of Hydrocyclones by Richard A. Arterburn, I was able to design the hydrocyclone with much clearer direction. For example, I have shortened the cyclindrical feed chamber to promote the development of the inner cyclone. To futher promote this development, I have also extended the length of the vortex finder. In order to solve the flow rate problem, I have designed hydrocyclone #3 to be much smaller; the total volume is now 20cm^{3} as opposed to the volume of hydrocyclone #2, which had a total volume of 100cm^{3} . However, I still wanted this design to be able to seperate slightly larger particulate contaminants from water, such as sand, so I had to ensure that the inlet and outlets were large enough to prevent clogging.
After the initial testing of Hydrocyclone 2 revealed an overflow:underflow volume ratio of 42:100 (an improvement on Hydrocyclone 1, but still not sufficient), I went back to reading literature, seeking instruction on how to adapt the design to increase overflow output.
