This is my fifth or sixth hydroclone design, this is the best working model so far.
The hydroclone is designed to separate solids from water in a pond. It can separate algae but it works best with removing debris from the water.
The input to the hydroclone is the off-centre 19mm inlet. The discharge is at the bottom and is designed for a 2L cocacola bottle to be attached to capture solids. The outlet -out of the top through a 19mm outlet.
It's basic operation is similar to a bagless vacuum cleaner. The water enters the inlet, it spirals around the first chamber in a vortex and gets accelerated past the accelerator. The vortex then makes a sharp turn at the bottom (near the coke bottle attachment) in which solids fall down into the coke bottle and clean water exits through the top.
All attachments are designed for 19mm piping. A standard 1.25, 1.5 or 2L coke bottle screws into the thread on the bottom (see pictures).
The design has been tested and works really well, there's not too much loss of flow and it does separate algae from the water (which is very similar in density to water).
This is suited more for small koi ponds (i.e. where there is debris in the water from the fish stirring up the silt on the bottom).
Apparently putting hydroclones in parallel is better than putting them in series, not sure why, just seems to be what's done. If your pump is too big for one hydroclone, print many and put them in parallel.
The design has been updated to include a more aggressive accelerator, parabolic nozzle, and a smaller outlet to significantly improve performance. It removes more than twice the amount of solids and also removes even smaller particles than the previous design.
A second design labelled NOT FOR ALGAE has been included and is only for water that needs solid separation only. If the water has any algae in it the algae will quickly block up this hydroclone design so use the normal one if you plan to put it in a pond.
This has been design to print up-side down. You should not need any support material. You can create a brim at the bottom to help it stick to the bed of needed.
Make all walls 1.2mm thick as a minimum if using PLA. If using ABS make the walls thicker as ABS is less rigid.
I used 20% infill but you don't need any infill if your printer is good at bridging gaps.
I used 0.3mm Z res for a fast print with a 0.4mm nozzle. You can really do whatever layer height you want.