Contemplating a new build, 2" valved reflux

[Nightforce]

I'm already contemplating a proper 2" column of the same type of a build as the one I'm working with now, with a double helix condenser and all copper parts. From the parent site design calculators it looks like I'd be able to get ~94.6% off a 40% wash at a fairly good rate (double the initial rate for 2 hr. but about 200ml/hr faster than what I have on average) and given non ideal conditions and comparing the performance of what I have, I should be able to get slightly better proof. I'll cannibalize the one I have and make a pot still out of if for flavored runs and stripping. I kinda like the design of the valved reflux 'cause I'm getting used to it, although it appears some of the other designs are more popular. The performance however seems about the same unless I'm mistaken, about 800-1200ml/hr of 93+% from a 10% wash. I'm planning on using 2 2"×1½"×2" tees, 2" 1.1m column (have 53" of 2" left) and 10" of 2" stack for the condenser housing. (43" column + 10" stack, 53" total). I was wondering if the design on moonshine-still.com sites reason for going from a 2" column to a 3" condenser housing is to reduce the vapor speed in the condenser stack or if it was just for ease of construction. I was going to go with a 1-7/8" OD double helix condenser with only a 2" housing to reduce the cost of the project (2"×1½" reducer and 2' of 3" pipe would be about $70).

Additionally, has anyone made a pot still with a condenser assembly designed like a Friedrick's style condenser. I'm thinking of making a pot still and instead of the standard lebig, use a condenser design that has 1½"×1¼" elbow mated to a 1¼"×2" Tee and the double helix coil would hang down into the tee with the vapor hitting the top of the condenser and blowing down the coil condensing the vapor. It would drain to a cap with a 3/8" outlet port. I'm working on a drawing of it that I'll try to post it so it's clearer.

Thanks to all.

[rad14701]

If you have your heart set on an offset head valved reflux column then sticking with a single diameter of copper would definitely reduce costs...

Copper fittings can get expensive, which is why so many members start out with a Bokakob dual slant plate inline LM reflux column... The major expense is the column itself, plus 1/4" or 3/8" condenser and take off tubing...

[kiwistiller]

I wouldn't have thought the running of an inline LM like boka's would be too significantly different to the valved design... others may know better than I.

[HookLine]

I was wondering if the design on moonshine-still.com sites reason for going from a 2" column to a 3" condenser housing is to reduce the vapor speed in the condenser stack or if it was just for ease of construction.

I am guessing it is to reduce vapour speed. But it is not necessary. A 2" double coil, 6-7" long, in 1/4" tube, (or a single 2" coil with a centre cold finger) will easily cope with what you are going to throw at it, with plenty of room to spare. In fact they will cope with the power coming up a 3" column.

Using 3" for the condenser section will just add cost, for no benefit.

[rad14701]

With the short length of the 3" section I'd be leaning more towards being able to fit more condenser coil into the 3" section than actual reduction of vapor speed... The two 90 degree turns are already slowing the vapor a bit... Less and cheaper fittings is the way to go...

[Hawke]

I've built both the VR and a boka inline. They both do the job.
The Boka inline was about 1/3 the cost and is a bit easier to drive.
Using 2" instead of 3" for the condencer shell would easily save $100 on the build of a VR rig.

[Nightforce]

I originally had hoped to use one still to do both a pot and reflux job but after lurking here for a while I see that it's just better to have one still for each job....i.e. use the right tool for the job. Given the column and packing are the same height and materials, which head produces a better product? Given the lack of a good set of plans, how critical are the plate location and alignment. Is it really as simple as hacking to overlapping plates into the column, one with a take off tube above it and a thermometer hole under the top one? I'm just wondering what is the simpler build to do. I have the 2" copper (2.125" OD) and can get some .050" copper flat stock. The only thing I see that I'd need is some ¼" tubing for the coil and a good needle valve, along with some type of connection hardware for the boiler.

I'll probably cannibalize what I've got soon (now that I have enough neutral for my needs for quite some time) to make a pot still, which I'm thinking of a simple 2' 1½" column to a 90 to a lebig. That will be for stripping and flavored runs. I kinda like the idea of a Friedrichs style condenser but don't know how feasible or efficient it would be. Thinking about one coil too, interchangeable between each still.

[olddog]

There are plans on the parent site with running instruction for a Bokabob, its it the "building a reflux still" section, that should help. A potstill is not that critical its just a column and a lyne arm leading to a condenser of your choice.

[Nightforce]

I drew up something and wonder if it would work.

Condenser Still 2 Model.pdf

(45.42 KiB) Downloaded 167 times

[olddog]

That's a Bokabob, the only difference is on the original Bokabob design the top plate is soldered to the bottom of the coil, meaning you only have to put one cut for a plate into the column, then the bottom plate and output tube are soldered in one operation, making it the only solder joint you have to do on the column.
Mine has two plates in the column like your design.

[Hawke]

Great drawing.
I would extend the overlap of the plates just a bit. (Go to 1.5 instead of the 1.375)
And, instead of the expensive threaded adapters, use a sweat coupler. Solder it to the column and have the head just slip fit. I use a few wraps of PTFE tape around the head, just below seat depth to seal mine. Flour paste would also work. Another advantage of the slip fit, is that you don't have to worry about placing the boiler in a set position, just twist the head to where you need it.

[HookLine]

With the short length of the 3" section I'd be leaning more towards being able to fit more condenser coil into the 3" section than actual reduction of vapor speed...

Fair point.

Excellent drawing, Nightforce.

I think the two plates are a little close together. Having them further apart than necessary is not a problem (within reason), but having them too close can cause choking. You have them as 0.325" apart, I would make that 0.5-0.75".

[rad14701]

Excellent drawing, Nightforce.

I think the two plates are a little close together. Having them further apart than necessary is not a problem (within reason), but having them too close can cause choking. You have them as 0.325" apart, I would make that 0.5-0.75".

Great drawing.
I would extend the overlap of the plates just a bit. (Go to 1.5 instead of the 1.375)
And, instead of the expensive threaded adapters, use a sweat coupler. Solder it to the column and have the head just slip fit. I use a few wraps of PTFE tape around the head, just below seat depth to seal mine. Flour paste would also work. Another advantage of the slip fit, is that you don't have to worry about placing the boiler in a set position, just twist the head to where you need it.

+1

[Nightforce]

I'm contemplating tearing apart what I've got and doing a new still this x-mas week. Going to use the 1½" for a pot still with some reducers to a ½×¾ lebig about 24" long with a turbulator and some copper mesh inserted. This will be for stripping runs (got several going) and eventually some flavored stuff later. Does the height of the pot still column make much of a difference? I was just going to make it as tall as need be to accommodate enough height so that the condenser drops into the collection jar with the column attached to the ¼ keg on a propane burner. (will take into account the option of converting to electric too).

As for the next build, here is the updated drawing.

I wanted to make the column connection to the keg with a tri-clamp ferrule, however, from the information I could dig up, a 2" tri-clamp I.D. is 1.88" and the O.D. of my 2" copper is 2.125". How do those who use a tri-clamp connect them?

[rad14701]

Your re-design looks a lot better...

One thing to consider is that you don't want any reflux that comes off the top plate to be able to drop directly back down into the packing... 100% of the top plate reflux should go into the collection cup section and only the overflow from the cup should drip into the packing... You can even cut the tab slot further from centerline and bend it beyond parallel with the column to hit "close" to the center of your packing... Being off 1/8" - 1/4" isn't going to make a huge difference...

You must like machining if you're going to go to the trouble of making a turned temp probe port...

I must be ass-backwards because I've always prototyped and then drawn up a design, with the exception of some minor napkin doodling...

[Hack]

I wanted to make the column connection to the keg with a tri-clamp ferrule, however, from the information I could dig up, a 2" tri-clamp I.D. is 1.88" and the O.D. of my 2" copper is 2.125". How do those who use a tri-clamp connect them?

I've never messed with a reflux, so I can't comment much on your design, but I want to compliment you on your well drawn plans.

For a triclamp connection try looking up the "easy flange". There's a thread on it around here somewhere and that may be the way you want to go.

[Nightforce]

No, I don't think you're the ass backwards one. LOL I do believe that is me.

I love machining and I have a bit of CAD experience from a previous position at work so I like to draw up every detail, then fabricate it. It helps me envision the product better; tolerances, fit, etc.

Thanks, I'll search for the easy flange thread ASAP.

EDIT: After some research it looks like the OD of the tri-clamp/clover ferrules are 2" so it should slip inside the 2" ID copper pipe and solder on nicely. Gonna give it a try.

[HookLine]

Love the drawings.

Two points

1) Extend the turbolator in the Liebig for the length of the cooling section. Don't have to, but will give the maximum benefit if you do. And do you have any turbulence generator in the coolant jacket?

2) Having the two holes in the cap on the sides, directly above the actual coils, is a good idea. Having a hole in the centre of the cap, ie above the hole in the centre of the coils, will encourage vapour to head up the centre hole, rather than into the coils. (This is particularly useful if you do not have a centre cold finger, and even if you do.)

[Hawke]

Hook,
I Would be concerned about the possibility of pooling with a full length ribbon turbulator, if the condencer is angled more toward horizontal. Not a problem if it's on a VM, where it is vertical.

[HookLine]

Hook,
I Would be concerned about the possibility of pooling with a full length ribbon turbulator, if the condencer is angled more toward horizontal. Not a problem if it's on a VM, where it is vertical.

Fair point, though if you make the turbolator a little loose inside the Liebig, then there should be plenty of room for the condensate to flow around it. Or just make a turbolator from some copper wire instead of copper plate. Doesn't take much to induce turbulence.

[Dnderhead]

I have one like that ,fits loose and it works good.

[Hawke]

Although my house, yard and shop are all trash heaps, when I build something, I tend to go with minimum tollerances. (Building inspector told me my shop was the first building in 10 years without a single gig on the sheet) Hard for me to leave something with a loose fit.

[Nightforce]

Here are some pics of the new condenser for my pot still. ½" inside ¾", water jacket will be 24" long with a ½" compression fitting to attach to the 1½" column. I wrapped 16 ga. copper wire around the ½" to create turbulence. I also turned some brass inserts for the ½" tee's to reduce the number of fittings as I'll be using ½" for the water inlet and outlet.

Outlet end with brass inlet.

Head end with compression fitting.

Overall view of the condenser without the ¾" jacket.

[olddog]

Nice job, I alway like to see nice copperwork.

[HookLine]

Looking good.

[Nightforce]

For the Bokakob style head, does the thickness of the slant plates make a difference? I have some pretty soft 0.022" copper and the hacksaw blade I tested measured out at ~0.027" but in my mind I was thinking more like 0.030+ copper.

[rad14701]

For the Bokakob style head, does the thickness of the slant plates make a difference? I have some pretty soft 0.022" copper and the hacksaw blade I tested measured out at ~0.027" but in my mind I was thinking more like 0.030+ copper.

Thickness makes no difference... Most just slit and hammer a piece of column tube flat and make plates from that... You just need to try to make the clots narrow enough so that you don't need a lot of solder to seal the plates in place... Also, it's easier to solder the plate in and then cut and file it flush with the column than to attempt to make a perfect plate and then solder it into the slot...

[HookLine]

You just need to try to make the slots narrow enough so that you don't need a lot of solder to seal the plates in place... Also, it's easier to solder the plate in and then cut and file it flush with the column than to attempt to make a perfect plate and then solder it into the slot...

+1

I fooled around with a short bit of 2" and a plate a while back, just a rough experiment to see how easy it was to make, and soldering them in can be tricky. Definitely get the tightest fit possible, and leave some excess plate sticking out to catch the solder. Then clean it up afterwards.