Perhaps my eyeopeningest "thing" of my 120 things in 20 years yet. At least within aquaponics. I have to say moving enough electrons to make a light glow was pretty cool.
Anyway, I felt reasonably comfortable with my understanding of the bell siphon. I thought I understood how it worked, what caused it to trigger, and what caused it to stop.
It turns out, I have no idea.
This thing's a total mystery.
It wouldn't be the first time something made perfect sense, but went un-noticed by me.
What I thought I'd do is be very clever and make a cluster of siphons.
There is this phenomenon where, when a bell siphon triggers the height, or head, of water can actually rise above the height of the surrounding depth.
I figured this would allow me to make a device that had a cluster of bell siphons, that would be force triggered by an uber siphon.
mmm
Picture this... get a bell siphon, and fill it with smaller bell siphons.
The original standpipe would be the lowest. The bell surrounding this would also encompass all the other bells for each additional siphon in the cluster
3 of the standpipes had a mini bell, the 4th had a maxi bell that covered all the bells. The 4th standpipe was also slightly lower so that it would trigger first. This 4th standpipe was the one that didnt have a private bell on it. (unseen in the photo behind the glass bells)
The plan was, the 4th standpipe would fill first. This would drain the uber bell of air and actually raise the water level above the other standpipes. This would in turn, of course, decisively trigger them. (this worked)
What this would mean is that a tiny flow (enough to trigger only one mini-siphon) would instantly trigger all 4 siphons. It would also mean that the drain would be so fast that the siphon would shut down in a very decisive manner, because it would be effectively pulling four times as much water as it might be if only one siphon were involved. To aid the shut down there is an air breather pipe (seen sticking out on the left) with the other end inside the big cover all bell. The big cover all bell is not shown because it blocks everything else, but sits so the bottom rests at the level the small breather pipe on the left meets the brown tape.
Most importantly, if there was a flow anywhere greater than enough to trigger 1 siphon, and less than the amount 4 siphons could cope with, this system would start and stop very decisively.
In a few trials, the system worked perfectly. I could trigger the system so that it started and stopped repeatedly with a flow rate of ...
2.5 seconds to fill a 500ml jug (my laundry tap on full)
And the same siphon also triggered at...
39 or 29 (it's hard to read my note) seconds to fill a 500 ml jug (my laundry tap on a trickle so that the stream was breaking up before it hit the jug
So it worked. It worked over a massively variable flow rate, and I'd made some kind of revolutionary new device.
But strange stuff happened all the time when I tried to reproduce the results.
I couldn't do it.
Sometimes it would work, others not.
Keep in mind, this thing was made of blutac, wire, and brown packing tape, so there is a fair chance I'll be able to refine it, but in short, I'm left feeling that I have much less of an understanding of the dynamics existing within a bell siphon than I thought I had before I started. The siphons didn't even always trigger in the same order.
I hate it when that happens.
I love it when that happens.
The true value of the scientific method is that it can show you that you know less that you thought, or you are just plain wrong, just as easily as it can show you how fabulous you are. An independent judge of fabulousness!
Valuable, but never comfortable :)
We live and learn.
My next step, is of course, to figure out what's going on, and make this device work.
When it worked it was a pretty impressive thing to watch, and much too valuable to give up on.
Wheels within wheels.
Or at least bubbles within bubbles.
Way cool.
