Mixing eductor-driven fractionation

[uryy4me]

WOW! What size tank is this suited for?

[dattack]

Hewo??

[Stoney Reef]

I found setting them very touchy but after discussing it with galleon, it appears we skimmed everything out of the water and that is why it was being touchy, so I would have to say, we would need to run it intermittantly on the 600 gallon coral tank. There are maybe 3 fish in the tank, and a couple of cucumbers and a couple of stars, so except for the corals there is significantly no bioload. Thus the intermittant skimmer performance.

[dattack]

Originally posted by Stoney Reef
I found setting them very touchy but after discussing it with galleon, it appears we skimmed everything out of the water and that is why it was being touchy, so I would have to say, we would need to run it intermittantly on the 600 gallon coral tank. There are maybe 3 fish in the tank, and a couple of cucumbers and a couple of stars, so except for the corals there is significantly no bioload. Thus the intermittant skimmer performance.

Thanks for the info. Is the concept the same "eductor" that aquatiecosystems sells on their website? If so, can I fit it like a beckett instead of making one out of pVC?

[Geoff]

i do not see why that would not work. keep us posted.

G~

[Stoney Reef]

yes, you could fit it like a beckett, but that is the whole reason for the PVC one, no acrylic fabrication neccessary, this is made for those people, who are DIY untalented! Thus the only real requirements are being able to swab some glue on some fitting and slide them together!

[Dman]

Being up here in the Great White North (c) I had a hard time finding the exact same PVC parts.
Namely the 2" tee and the square bottomed reducer.
So I had to improvise:

[Dman]

and here is the internals:

[Dman]

One last question before I try and put this puppy into action.
Is there a reason that the air/water mixture is directed UP once it reaches the skimmer body proper?
I was actually thinking of directing the mix downward at a 45 degree angle. Rather than intersect the skimmer body with a Tee fitting intersect with the body of the skimmer with a Wye fitting.
Whadday think?
Dman
:spin:

[Geoff]

the reason i think it was shot upwards is (Chris, by all means correct me if i am wrong) to keep the bubbles from being prematurely evacuated from the chamber. the force coming out of the eductor could possibly shoot some of the bubbles out of the bottom. on the pics on page one. had to shoot the mixture somewhere, sideways i could see being a problem, so up it is.

so depending on where your skimmer outlet is you may also run into bubble problems with where you inject the mixture into the chamber.

G~

[Dman]

The exit point is about three feet below the injection site, with another three feet above. I was thinking that that would be enough room.
Perhaps I'll try running briefly press fitted together.
Geoff, you mentioned that injecting sidways was going to present a problem, why was that?
Not that I'm completely new to this, perhaps angling the nozzle into the sidewall to create a swirl may be useful?
Thanks
Dman

[snazlord]

The air-water mixture is injected up to create a counter-current effect (air and water moving in opposite directions). This increases the contact time betweent the bubbles and the water. The air water mixture enters the reaction chamber moving upwards, then the water "turns around" (it has to exit at the bottom) while the bubbles continue to travel upwards.

Theoretically, the same counter-current effect would be achieved by injecting downwards, but in reverse: the mixture would be injected downwards and the water would continue down to the exit while the air bubbles would have to "turn around" to get to the top. The problem with this set-up, as Geoff mentioned, is that the very small size of the air bubbles makes it much harder for them to turn around if injected downwards; rather, many of them will get swept away by the current and will end up in your sump.

Injecting sideways would not be a problem (as long as the jet wasn't to forcefully directed at a seam which may over time cause a leak), but i don't think you'd get the same counter-current effect, which may reduce the skimmer's effectiveness somewhat. (purely theoretically speaking; no data whatsoever to back up that point)

[Dman]

Snazlord,
Thanks for the explanation.
So it looks like a balancing act in regards to where the air/water mixture comes in, the direction it's travelling in, the initial exit point of the "scrubbed" water, height of the overflow and the height of the reaction chamber above the injection site.
Sould keep moi busy for a week or so
Thanks again
Dman

p.s. I'll post more pics as I make progress.

[Stoney Reef]

Don't forget the sound of the jet engine taking off in your room!!!!! That is an added bonus and makes it worth it all by itself!

[Dman]

The sound isn't a concern as the unit will be in the basement along side a 1/2 HP Iwaki. So it will sound like two jets throttling up.
Dman