2 inch Boka to CCVM. DAD300 was right.

[underdog]

Well, after about five years, I finally bit the bullet and re-did my 2" Boka still into a CCVM. It was originally built as a modular still, which made the conversion easy. I re-used my 3/8 copper reflux condenser and used a bunch of new stainless parts and tri-clamps bought off of eBay. I built the product condenser from parts purchased there as well. It's 3/4 over 1/2 copper and only had one leak when I pressured it up. It was a small water leak on the outside, so instead of dismantling the entire thing and re-doing the joints, I just brazed over the offending joint with sil-fos brazing wire usually used in HVAC work. The column is 48" of SPP (bought on eBay from that guy in Poland) over a 13 gallon milk can boiler powered by a 5500 watt water heater element.

I just did my cleaning run. Some observations:

1. This thing is fast. I have easily doubled my product make over the Boka. I have a stream now instead of a fast drip.
2. The vapor temperature seems locked in. It stayed at the same temperature until very late in the run. I know exactly how much 96% I put in the boiler (three liters) and I didn't see any increase until I was well into the last liter. The vapor temperature reacted immediately to any change in the condenser height. There's a K thermocouple in the vapor takeoff elbow, routed through an Omaga temp indicator to an old laptop that allows me to set alarms, graph the results, etc. Some folks have varying ideas about vapor temperature monitoring, but I have 34 years of commercial petroleum distillation experience, so it's information that I'm used to working with.
3. The reflux condenser let a small amount come out the product line - even with the condenser stuck in as much as I could - I've since cut 2" off of the top spool, which will allow me to push my condenser lower into the tee piece. Hopefully. we'll get it all next time. It was only a drip, but I'd like to condense everything at the start of a run.
4. The new Liebig product condenser does knock down all of the vapor, but the output temperature runs about 92F instead of the 65F that I used to get from the very low flow through my Boka's old product cooler (1/2 over 1/4). I'm going to have to use a table to adjust my hydrometer readings because they're calibrated for 60F.
5. As I approached the end of the run, the flow dropped way off and then the vapor temperature began to increase. This is going to be much easier to operate than the Boka, which didn't give me such obvious feedback.
All in all, I'm going to have to learn how to operate this new setup, but as of now, it seems a lot less finicky and much easier to operate than my old LM still. We'll see how I feel about it after a few more runs, but right now, I'm excited.
I'll be starting a new UJSSM batch up tomorrow after I run out for some sugar.

Thanks to DAD300's excellent posts and explanations. It made it easy.

[miletwo]

Sounds like good progress in the right direction. Congrats!

Might consider a more efficient condenser for a future upgrade as I bet you could knock a couple feet off the condenser length and height of your column at the same time. My god man, do you need a ladder to run that thing!?

[LWTCS]

Nice follow up post.

[Deplorable]

You're going to really enjoy that for making neutral. Once you figure it out, it will be boring. I agree with miletwo, build a shotty and knock 8 inches off the height. 40" of good packing under the take off is all you need for a 2" CCVM. I'm 5 inches shy of that and pull "e95" with copper mesh at a respectful rate.

[shadylane]

Thanks to DAD300's excellent posts and explanations. It made it easy.

The design is so obvious and effective.
It's amazing no one thought of it before DAD.
I figure, He gained a whole bunch of good karma for taking the time to share with us.

[LWTCS]

That's not Dad's.
Manu has the earlier time signature as I recall.

[Deplorable]

That's not Dad's.
Manu has the earlier time signature as I recall.

I think you're correct. I need to go back and look, but I think Dad even mentions Manu's work in his thread.
Either way if I can run one and get excellent results on my 2nd run, it's a pretty fool proof design. Because I've been called a damned fool a time or nine.

[shadylane]

That's not Dad's.
Manu has the earlier time signature as I recall.

I stand corrected
Manu de hanoi has made many great contributions.

[kimbodious]

I was blown away by the simplicity of the design and operation when I first read about it in the thread started by DAD300.

[Swingbattermn]

I’m 3/4 of the way through a nearly identical build… is there a need for the funnel type reducer and smaller pipe size between the lyne arm and the Liebig… or can the 2” output on the lyne arm just be reduced directly to the Liebig? Depending on the rate of heating, I imagine this will bottleneck the vapor path more than the funnel reducer… but will it create enough back pressure to be an issue? Thoughts from you pro’s who have likely tested it already?

[Hambone]

Swing,

I doubt that back pressure would be an issue, but vapor speed increase may induce a bit of huffing….

[ThomasBrewer]

Swing,

What you don't want is place for the condensate to pool. Without the funnel-type diameter reduction, you can get a little shelf of liquid that smears your run.

[kimbodious]

Swing,

What you don't want is place for the condensate to pool. Without the funnel-type diameter reduction, you can get a little shelf of liquid that smears your run.

It should only be vapour passing through the lyne arm to the product condenser.

[LWTCS]

Swing,

What you don't want is place for the condensate to pool. Without the funnel-type diameter reduction, you can get a little shelf of liquid that smears your run.

It should only be vapour passing through the lyne arm to the product condenser.

Yep.
Gotta read the title of the thread.

[ThomasBrewer]

Swing,

What you don't want is place for the condensate to pool. Without the funnel-type diameter reduction, you can get a little shelf of liquid that smears your run.

It should only be vapour passing through the lyne arm to the product condenser.

Been away for a bit. Nope. That's all good in theory, but if you leave a reservoir for liquid to pool, it will. Unless fully insulated (most folks don't after the column), you will get condensation and smearing.

Edit: Respectfully, here's a very common situation that leads to smearing. It's a 2" to 1" hard transition. The offtake will eventually reach a homogenous temperature, but you'll have a little pocket of liquid in the circled area the entire time. You want a funnel-type reducer. Ask me how I know.

[LWTCS]

Better yet, an eccentric orientation.