I was thinking of how to make a tube cell, and do it with very few parts, and MODULAR. I came up with this. Now I might not have been the first to think of this, but I didn’t see it. I kind of took Spike's cell and ran with it. It uses 2 tubes. The first tube is 1" dia and 14" lg. it has 2 plugs in it about 2" from the ends. it also has 2 sets of holes on each end just outside the plugs. The next tube is 1.25"dia and 12'lg and slips over and has an o-ring on each end. Water then flows thru the inner tube to the first plug, transfers thru the small holes to the area between the tubes, travels thru to the other end and transfers back to the inner tube and to a reservoir where the hho and water can separate then pumped back into the cell. You could run them off a parallel manifold, and add as many cells as you need. Here is a model view and a section view of one end.
What do you all think??
Robert