My 2.5” Bok build

[Eskymo]

Hey all, after many years of using my 2” bok, I’m getting around to building a 2.5” bok over a 50lt keg. I’ve gone thru the LM/VM,CCM debates, and the 2” vs 3” vs 4” etc, but will stick to what I’m comfy with. My needs are modest... I just built a 2” bok for my son, and by using scoria rock instead if scrubbies, we can pull 95% at 30ml/min instead of my usual 20ml/min.
Now, for a chuckle, I’m putting a 4” perf plate under my new 2.5” column. My question is, will there be any measurable benefit? (btw, I’m using 2.5” as all the 2.5” gear is +30% over 2”, whereas 3” gear is +200% dearer.)

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For the RC, I’ve simply used 3/8th inch copper tube, single wound.

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I’m not sure why more don’t use 2.5”, I can’t seem to find any builds at all. Only comments from the past.
I was happy with 30ml/minute at 95% on the 2”, so it’ll be interesting to see what this one gives out.
Comments, critiques welcone ;-)

[RC Al]

Nice looking rig mate

What hole size - count are you using on the plate? Bath depth?
The ball may have to be a bit taller to work efficiently, Most go 4"+ high on a 4", my research so far suggests 6" or so to avoid entrainment on even the larger diameter rigs, any more is for cleaning access

How much power are you using?

[scythe]

Had to do the calculations on 30ml/min = 1.8L/hr.
Not as slow as i first thought.

[Eskymo]

Nice looking rig mate

What hole size - count are you using on the plate? Bath depth?
The ball may have to be a bit taller to work efficiently, Most go 4"+ high on a 4", my research so far suggests 6" or so to avoid entrainment on even the larger diameter rigs, any more is for cleaning access

How much power are you using?

I just ‘guesstimated’ after reading as much as i could find. 2mm hole on a 5mm grid. I haven’t installed the heater yet, but being restrained to a 10amp circuit, I’m thinking a 3kw low density coupled to my 10kw controller. That way I’ll wring as much as i can out of it. It’ll be a bit slow to heat up... Yeah, i wondered about the small ball and its efficacy. Looks more of an afterthought now i look at it. Worst-case, it may help to break up the vapour flow a little. Bath depth is only about 20mm. I put a copper piece under the downcomer to stop vapour blowback Once i finish the build, I’ll be better able to judge how much more than the 2” it’ll do. :smile: