[Delphinus]

I'm resurrecting this ancient thread, because a couple of us have built reactors recently using this design.

Hindsight being 20/20 I have a few suggestions for anyone comtemplating this design for their own DIY reactors.

1) Go with 3/4" PVC for the piping. I went with 1/2" because the mag drive inlet and outlet are both 1/2". But 1/2" does reduce pump output due to friction. With 3/4" and just bushing'ed down to 1/2" at the pump, you would be able get better flow from your pump.

One drawback with this design is that the piping is in place permanently. Once it's in and glued you're never going to be able to say, swap up from 1/2" to 3/4" without first hacksawing the reactor to pieces and rebuilding from scratch. So go with the 3/4" from the start.


2) The pump sits on a localized high point of the piping. Ie., it sits higher than it's intake, and the piping on the outlet goes DOWN before goes back up. This means that any air in the line will stay trapped in the pump, and it makes for priming the pump to be a chore. The pump basically cannot prime itself whatsoever. To prime it, you have to turn on your pump, undo one of your unions, and let the air out until the pump is pushing water. This lets out a lot of water onto your floor.

One potential way around this, is take the output of the pump and aim it UPWARDS rather than sideways. Have your reactor effluent on the high point of this pipe. This way the pump can push out the air by itself. Yes, one drawback is that there is now yet another 90-degree bend in the piping and this means reduced pump efficiency. BUT, if you go with 3/4" PVC instead of 1/2" maybe that will work to somewhat reduce the losses due to friction.

3) I'm not sure what the solution is just yet, but, I'm having a heck of a time clearing the lower chamber of bubbles. I was going to not worry about it, but, as I leave the reactor running for long periods of time, the bubbles in the lower chamber grow. And eventually it becomes a level drop in the lower chamber because the air bubbles just grow, and grow, and grow. I think that what is happening is that the holes joining the two chambers don't allow enough flow, thus, the pressure in the lower chamber just drops and drops. This suggests to me, that left unchecked and without some kind of corrective measure, eventually the pump will end up cavitating because it will not be able to draw from the lower chamber any longer (because it's pulling against negative pressure).

Hopefully if there is no air in the lower chamber, the risk of this might be reduced. But since I am having trouble even clearing the chamber of "that last little air bubble that refuses to leave" .... I think maybe I don't have enough holes or my holes are too small. So I'm going to empty my reactor and see what kind of action I can take (it's going to be difficult to get into that chamber and enlargen them holes ... maybe with a dremel snake thing .. there's no way I'm going to be able to get a drill down that tube .... :?