drum swirl filter

[overkill]

hi guys i was trying to think of a cheap way to make a good quality swirl filter. my system will be run as two seperate systems and i need two filters,this is the way i did it. you need a plastic welder which worked for me cause i wanted a good reason to get a plastic welder.i used two drums to make one filter, i was hoping to make it out of one but their isnt enough material to work with, you could make two filters out of two drums if you were happy to use the top of the drum as a base of a filter.this one is just a test to see if i could get the plastic to form the cone.

First i made a template.Their is a good free metric cone calculator at
http://www.red-bag.com/engintools/calccone.php


This is the drum i cut the cone out of, you can see thier is enough material to make another cone


this is the finshed cone,the plastic forms the cone pretty easily i just rolled it up like a cone and then clamped it to weld


Like my scroll saw. I used it to trim the excess material from the fitting that i cut of the top of one of the drums. No responsibility is taken by me for the loss of fingers if you try this at home.


I decided to put this fitting in the base of the drum because these drums dont have flat bottons to seal on and you dont have to buy a fitting for it




this is the finished product not bad for a first try, all the welds turned out good,its really strongand no leaks


when i make the the real ones i will do a few things differently, use a drum with a large lid and section it so its chopped low and i will get some proper hdpe threaded fittings for the inlet and outlet and use a jig to keep it round this one is a bit out of round.if anyone wants it in perth make a offer

[RupertofOZ]

Nice welding... you've obviously done a bit before...

[Biggles1212]

Looks great,

Did something similar as well on my post here

Try to get a lot more height into you filter and then fill it tangentially from the side. It's basically a thickener we use a lot in the mines to float water out of slurry in a dewatering process.

With a plastic welder the sky is the limit. I think every aquaponic fanatic needs one.

[overkill]

hi rupe,biggles

ive never done any plastic welding before but ive done heaps of metal fabrication work, but its really easy i just reserched it on the web and if you get a speed tip its similar to using hot glue gun. I was restricted on the height of the filter because i had already cut the side out of the drum that used for base but in saying that my real ones arent planned to be much taller does the height of the vortex make it more efficent, they will be fed from the side i just didnt want to waste a fitting until i make a flash one like yours.your right about needing a welder all i need now is a lathe and im set. thanks for your input guys.

[Biggles1212]

Hi,

The height gives the fish waste time to settle. So there's a minimum height you need. If you take a normal class 10 hdpe pipe and cut it at say 25 degrees it should come in press tangential, you just weld it in.

The diameter of the swirl filter controls the settling velocity. Water is constantly flowing up and out so the bigger the diameter the slower the water moves. So for a given flow into the filter, there is a minimum diameter for the swirl filter, or the other way round, for a given diameter, there is a maximum inlet flow rate.

A blue drum is around 60cm so if your using a 25mm standpipe for you bell siphon, and it works, you should be safe as the operating flow rates of the bell siphon are within spec.

[jprs22]

Nice! what kind of plastic welder did you use?

[Biggidaman]

do you have any finished photos of it in action i'm courious to how it works