karimwassef
Active member
I realize that this may not be desirable by many others but since it took me a while to get right, I thought I'd post it here in case someone else is looking for a solution.
I had a 2" PVC center overflow that I needed to support >3000 gph flow but without a full siphon. I intentionally wanted it to pull air and create a large mass of bubbles. I also needed to have a large opening mesh guard to keep living things from getting sucked into the sump.
To get the overflow to support the gph, I used a 3" to 2" reducer backwards. The large 3" opening created a large vortex and funneled the frothy flow down the 2" overflow pipe. To get more air, I was able to add a tee.
The difficulty came in adding the protective mesh. It ran fine for a few minutes but then the vortex disappeared as the flow rate dropped dramatically. It wasn't debris getting caught in the mesh. I think it was a thin layer of frothy flow over the center of the mesh that changed the surface tension there and stopped a vortex from forming.
The solution was a short piece of 1" PVC and a 1" coupler above the mesh. This ensured that the flow inside the mesh had a channel of air above it so a vortex could form.
It sounds convoluted but it works great (for my intended application).
Oh - and I did have an emergency overflow that saved the day multiple times while I experimented.
Pics:
<a href="http://s1062.photobucket.com/user/karimwassef/media/2A545162-48B3-4563-88F2-CD032417BBE9_zps8vwh6bje.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/2A545162-48B3-4563-88F2-CD032417BBE9_zps8vwh6bje.jpg" border="0" alt=" photo 2A545162-48B3-4563-88F2-CD032417BBE9_zps8vwh6bje.jpg"></a>
<a href="http://s1062.photobucket.com/user/karimwassef/media/9265A31C-0308-4A07-AA94-1F69C8F42861_zpscjgz4f9n.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/9265A31C-0308-4A07-AA94-1F69C8F42861_zpscjgz4f9n.jpg" border="0" alt=" photo 9265A31C-0308-4A07-AA94-1F69C8F42861_zpscjgz4f9n.jpg"></a>
The tee alternates as an air inlet and a secondary purge. It oscillates in function.
I'm not sure I understand all the fluid dynamics but it works consistently now.
If anything changes, I'll update here.
I had a 2" PVC center overflow that I needed to support >3000 gph flow but without a full siphon. I intentionally wanted it to pull air and create a large mass of bubbles. I also needed to have a large opening mesh guard to keep living things from getting sucked into the sump.
To get the overflow to support the gph, I used a 3" to 2" reducer backwards. The large 3" opening created a large vortex and funneled the frothy flow down the 2" overflow pipe. To get more air, I was able to add a tee.
The difficulty came in adding the protective mesh. It ran fine for a few minutes but then the vortex disappeared as the flow rate dropped dramatically. It wasn't debris getting caught in the mesh. I think it was a thin layer of frothy flow over the center of the mesh that changed the surface tension there and stopped a vortex from forming.
The solution was a short piece of 1" PVC and a 1" coupler above the mesh. This ensured that the flow inside the mesh had a channel of air above it so a vortex could form.
It sounds convoluted but it works great (for my intended application).
Oh - and I did have an emergency overflow that saved the day multiple times while I experimented.
Pics:
<a href="http://s1062.photobucket.com/user/karimwassef/media/2A545162-48B3-4563-88F2-CD032417BBE9_zps8vwh6bje.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/2A545162-48B3-4563-88F2-CD032417BBE9_zps8vwh6bje.jpg" border="0" alt=" photo 2A545162-48B3-4563-88F2-CD032417BBE9_zps8vwh6bje.jpg"></a>
<a href="http://s1062.photobucket.com/user/karimwassef/media/9265A31C-0308-4A07-AA94-1F69C8F42861_zpscjgz4f9n.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/9265A31C-0308-4A07-AA94-1F69C8F42861_zpscjgz4f9n.jpg" border="0" alt=" photo 9265A31C-0308-4A07-AA94-1F69C8F42861_zpscjgz4f9n.jpg"></a>
The tee alternates as an air inlet and a secondary purge. It oscillates in function.
I'm not sure I understand all the fluid dynamics but it works consistently now.
If anything changes, I'll update here.
