CCVM Design

[Mr Sippy]

I briefly started on this column a couple months ago but only recently have picked it up again. But I’m having reservations about my design now. All recommend the takeoff port be same size as column to maintain 1:1 reflux ratio. Most of the dozen or so designs I’ve looked at also employ a downturned 90 of the same size before transitioning to the product condenser, although some do not.

In my configuration I wanted to use my existing condenser in which the vapor path reduces from the 3” tee to 1.5” to the 1” condenser entry over 14”, horizontal. The condenser itself is vertical. I wondered about that effect on reflux ratio and started poking around. DAD300 addressed this question (http://homedistiller.org/forum/viewtopi ... 17&t=41442) a while back when the CCVM was relatively new (I think) and while his logic seems sound, I don’t think I’ve seen any complaints about a reducing horizontal span. Maybe they’re under reported, maybe I’ve missed them. And because sensibilities can change with experience and observation maybe there are new opinions since 2013 on this matter. User problems with the CCVM seem to be mostly operational (power and/or cooling)

Like other column folks, my goal is to maximize purity and minimize time for a given a defined setup. So I’m wondering, from the experience of others, if my configuration will show as dramatic reduction (or is it increase?) in reflux ratio as DAD suggested back then. HookLine seemed to think it will not. I don’t mind the additional time and expense incorporating a 3” 90 with a new condenser, but if I don’t have to…

I purposefully left out other parameters (height, packing, reflux condenser, etc) for brevity and because I thought my question was independent of them. I intend to include all that and more as my build progresses.
Thoughts, advice,… clarity? Thanks

[kimbodious]

gday Sippy
I have gone from a CM to VM to CCVM reflux column still. I love the simplicity of running the CCVM. With a VM/CCVM still the vapour column splits off at the offtake. If there is no difference between the cross sectional area of the offtake and the column then the vapour column splits more or less evenly (half continues up, hald exits via the offtake). If there is a restriction at the offtake then the split of the vapour column is more or less proportional with the different cross sectional areas. With your setup, most of the vapour continues up to be refluxed (v. high purity) and a much lower (but purer) amount of vapour exits via the offtake. It is a tradeoff between output rates and purity (to a point). IMHO Keep the CSAs as close to each other at least until the product condenser. Check out the link below for my 2" CCVM system - I achieve about 1 litre per hour output but at 95% ABV.

[Mr Sippy]

gday to you kimbodious, thank you. So a 3" path to the condenser it is. That's a nice looking rig you've got. Mine won't be near that tall, being in the basement. I see that you have a reducer transition to the condenser. I think I may reduce from the 3" to 2" pipe which contains the ss corrugated tube. If I use a 3/4" over 1/2" liebig it will involve a 2nd reducer. But I'll have about 8" of narrowing instead of 14", although it's vertical rather than horizontal, if that even matters. With 70 looks and one reply I wonder if I'm overthinking this Thanks again.

[kimbodious]

gday to you kimbodious, thank you. So a 3" path to the condenser it is. ... I see that you have a reducer transition to the condenser.

Thanks. Nope it is 2" right through apart from the 2"-3/4" endcap reducer for the output tube (after the SD Big Baby condenser). Yours would be fine with a 3" tee for the offtake in to a 3" elbow and then reduce down to the Liebig.

Raise up to the growing band of CCVM reflux still operators