rash wrote:Pretty sure mine are like this for my 3" column.
Per plate;
2 x 1" caps with 5mm high slots, 5mm apart. Caps are 30mm high.
Risers are 3/4" diam, 25mm high.
Downcomers are 3/4" diam, 20mm above plate but about 75mm total length with a 1" cup on the bottom (cap is about 15mm deep i think).
Works well so far. :handgestures-thumbupleft:
Ash.
db1979 wrote:Just make sure the hole you drill in your riser is not lower than the top of the downcomer. The caps in my 2" build were soldered to the plate so that the risers were not attached to them and a gap exists between them.
db1979 wrote:Why did you want 7mm slots in your caps? If you're going for only 10 - 15 mm bath depth I think you'll want bubbles forming lower than 7 mm off the plate. I think my 1" caps on my 2" bubbler had slots only about 2 or 3 mm deep. And they work fine.
Otherwise, hit go and build it :handgestures-thumbupleft:
scythe wrote:Also why are your caps so small?
I would have thought a cap height of 25mm would be better, allowing your riser to be higher.
With cap design its mainly about open area, if you match it all up it will work better, it will still work if you don't, but it will be better if you do.
And by all of it i mean:
Cross sectional area of the ID of the riser,
Area of the holes you drill at the top of the riser,
Area between riser OD and cap ID,
And area of the slots you cut out.
Makes those the same and the vapour will flow freely, not smoothly.
ThePaterPiper wrote:would it not be slightly advantageous to make the area of the slots very slightly less than the area of the riser ID and holes at top to create a very slight pressure to stop liquid entering the bubble cap? Not that it would be that big an issue, but for maximum efficiency? :think:
scythe wrote:No don't restrict a bubble cap.
The entire column will be under the same pressure.
The bubble cap is a more difficult path than the downcomer and liquids are lazy.
I wouldnt use 3/4" caps.
Unless you have a few of them.
But the work involved in a 3/4" cap is the same as a 1" cap.
3/4" cap area
Pi × R^2 = area
3.1415 × 9.53^2 = 286.2mm^2
Cap - riser
286-93 = 193mm^2
So there is plenty of area in the reversal zone.
2×Pi×R = circumference
2×3.1415×9.53= 59.9
59.9÷19= 3.1mm between slots
So you will only have 1.75mm between cuts or less which is going to be a pain.
Go bigger caps and risers.
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