VM Project

[eskymo]

Hi all! New to the site, but been quietly pulling 96+% for the last 5 years on my NS still. The only issue was always the sloooow output rate. Thought it was about time for a new project, so was looking up info on the Minibok. Well, I saw a reference to VM stills, and the poor ol' Bok died on the operating table!
My trouble is, I know absolutely ziltch about VM! I've put together a drawing of what I'd like to build, but it needs constructive critism please! I can source all bits from Reece Plumbing around Brisbane, but at the price, I'd like to be in the ball-park first go! I've learned so much from you guys already, Hook, Punkin, and the rest of you, so a biiiig thanks already!Now, let's see if I can get a pic up... ( you can be as harsh as you like, I think any input is good input!) Rob, aka eskymo

[HookLine]

Welcome.

You need to seriously reduce the size of the pic before we can talk. It is unviewable as it is.

[eskymo]

Ouch! I see what you mean! Dumb question, what size will fit? I can resize, then resubmit it. Thanks for the welcome too!

[HookLine]

50 kB should be plenty.

[eskymo]

Sorry about the rude intro! I hope I did it right. I'll upload a 53kb pic, and hopefully it won't swamp everything again!. (Now I know why I don't like computers... ) Again, I do appreciate any input before I go shopping.

[HookLine]

Okay, that's fine. Thanks.

Avoid Reece if you can, they are expensive buggers.

Your design will work okay. But it can be improved.

The 12" coil condenser is overkill. 6" of double coil condenser is enough.

Make the packing section of the column 8-12" higher if you can (4.5-5'). If you already have the 4' piece, it will do. If you have not cut it yet, then the 6" you save on the condenser height can go onto the packing section.

The valve can be put after the 90º downturn, before the Liebig condenser, if you want. It will work as well.

Personally, I don't like brass valves in stills. Get stainless, you won't regret it.

Some, like Minime, are getting good results using ball valves, which are quite a bit cheaper.

The crimps in the vapour tube in the Liebig will work, but will also make it hard to clean out if you need to. IMHO, it is better of leaving it circular, and just put a thin strip of copper mesh loosely inside the length of the tube to get the turbulence inside it.

1380 w is a good size for the main run for a 2", but it will take a while to heat up the wash, maybe an hour for 20 litres of wash. If you already have the boiler it will do.

[eskymo]

Done! Thanks for that! I've yet to buy the 2" copper, so I can easily add to the column length. Putting the gate valve vertical may help balance out the whole thing. Ditto with the liebig: Mesh is easier! I already have the boiler, so stuck with 1380w until I add a 2nd element to speed the heatup stage. I'll work it so I can turn it off once up to speed. I'm about an hour out of the 'big smoke' so not sure what other options i have re buying the bits. The local plumbers don't want to know me. I feel a little easier stepping into the project now. Wasn't sure about the half-inch stuff, so I'm glad I asked. Thanks again for the input! I'll keep checking on the various VM 'goings on', and keep learning. BTW, any ideas on what I can expect re output? I was getting about 1200ml / hr @ 95-96%+ on the LM, but this is the great unknown... I'm interested in getting as pure as possible, then just adding flavour as I dilute.

[Hawke]

... I'm interested in getting as pure as possible, then just adding flavour as I dilute.

Missing out on some great tasting whiskeys and rums by using flavorings. No substitute for the real thing.
The VM should perform almost identical to the LM as far as output.

[punkin]

I was running about twice the power into a similar column and getting around the same output. Very easy to run too.

Get your price from Reece for all the pipe and fittings up to the valve and give me a PM. Might be able to save ya a few bucks.

[pHneutral]

I kinda like the Alihn style condenser. In chem those are usually used for reflux, but thats more a function of semantics. Its pretty efficient since the vapor is being recondensed several times by the varying volumes. Its just not smooth, in terms of output, but that may not be a trouble for this application.

[eskymo]

Hey, thanks 4 the replies! Hawke, I'd like to start trying to make my own flavours. I think that's the next step towards the real deal. I did try some basics when i started a few years ago, but made such a mess of it, I gave up. Time to try again? Punkin, Thanks, I reckon that if I got around the same as my LM, I'd be happy. I may just do that with the bits I need. I'd rather not take advantage of your generousity if it cuts you short in any way tho. pH, I kinda liked the look of the condenser too! I stumbled across a scientific site that was experimenting with bulk distillation for something else, and they made up one of these about 3 metres long! As Hook said, the potential for cleaning issues is the only downside. Mind you, I'm only using it for my 2nd strip, so shouldn't be any solids in there...I hope! I'm lookin' forward to making this thing up. Trying to find whether a Bernzomatic MAPP torch will be hot enuf. Plan 2: just bought a 2nd-hand Colt44 oxy set (sans bottles) from 'that online place', so may have to learn to use that in a hurry.

[Harry]

The crimps in the vapour tube in the Liebig will work, but will also make it hard to clean out if you need to. IMHO, it is better of leaving it circular, and just put a thin strip of copper mesh loosely inside the length of the tube to get the turbulence inside it.

Very easy to clean. Plug the end with a cork or similar. Fill it with white table vinegar or even lees from the still. Leave it stand for overnite. Empty, flush & rinse with clean water. I do the whole column, scrubbers in situ, the same way.

[eskymo]

Sounds easy! Thanks Harry, I'll use the crimped system then. Apart from lookin cool, (I know no-one will see it) but to me, it seems that the crimps would give the vapour the most contact with the water cooling. I was thinking of making it about 450mm, so it should be long enough. The other issue is having to make a dedicated stripping head. i gather the only way to use the VM head would be to remove the top condenser and cap it? I previously unscrewed my column and attached the NS head to the boiler for stripping. May just make up a basic Bok head to screw into the boiler top. Would it only need to have a condenser and an offtake plate/pipe, or should I still put the top plate in as well? Sorry about the barrage of questions, but it's the best way for me to learn, from others who've 'been there' already. Thanks!

[Hawke]

Use a union to connect your liebeg, then all you need for stripping is a short up pipe, an elbow and another union to hook the liebeg to. (makes a very basic potstill)

[xx7777xx]

The valve can be put after the 90º downturn, before the Liebig condenser, if you want. It will work as well.

Personally, I don't like brass valves in stills. Get stainless, you won't regret it.

Some, like Minime, are getting good results using ball valves, which are quite a bit cheaper.

-I have put my valve after the 90º as suggested and it works great. Here is a design picture if you are interested (http://i410.photobucket.com/albums/pp18 ... Design.jpg). That said there have been a few discussions suggesting that having the valve vertical leads to condensate buildup on behind the valve during equalization. I'm not sure if we reached consensus on which is better but thought I'd bring it up.

-I am very happy with the gate valve becuase it provides such granular control, so if you can spare the extra $$ I would recommend it.
-You may want to consider a joint above your T if you want to the ability to further reduce reflux by removing your condenser and adding a sealed cap when running as a pot still.
-Final small though. I opted for a cap on the top of my reflux condenser (not soldered on to the 2") with a vent tube to easy the management of the consdenser leads. (http://i410.photobucket.com/albums/pp18 ... cture1.jpg)

x7

[Harry]

Sounds easy! Thanks Harry, I'll use the crimped system then. Apart from lookin cool, (I know no-one will see it) but to me, it seems that the crimps would give the vapour the most contact with the water cooling. I was thinking of making it about 450mm, so it should be long enough. The other issue is having to make a dedicated stripping head. i gather the only way to use the VM head would be to remove the top condenser and cap it? I previously unscrewed my column and attached the NS head to the boiler for stripping. May just make up a basic Bok head to screw into the boiler top. Would it only need to have a condenser and an offtake plate/pipe, or should I still put the top plate in as well? Sorry about the barrage of questions, but it's the best way for me to learn, from others who've 'been there' already. Thanks!

A straight inner tube Liebig with mesh or a twisted insert (correct name is 'turbulators', http://www.flamingochillers.com/heat-exchangers.html) will provide turbulence for the vapor side flow.

A crimped inner tube has superior heat transfer capability because it gives turbulence to BOTH vapor and the coolant (water). This removed heat much faster for a given length. What this means is that Liebigs can be made shorter than usual, which reduces build costs while maintaining efficiency. Yours (450mm) is plenty for the still design you have chosen.


Stripping only requires a potstill configuration. There's plenty of different ways to do that. Look around here and other sites.

[HookLine]

The crimps in the vapour tube in the Liebig will work, but will also make it hard to clean out if you need to. IMHO, it is better of leaving it circular, and just put a thin strip of copper mesh loosely inside the length of the tube to get the turbulence inside it.

Very easy to clean. Plug the end with a cork or similar. Fill it with white table vinegar or even lees from the still. Leave it stand for overnite. Empty, flush & rinse with clean water. I do the whole column, scrubbers in situ, the same way.

A straight inner tube Liebig with mesh or a twisted insert (correct name is 'turbulators', http://www.flamingochillers.com/heat-exchangers.html) will provide turbulence for the vapor side flow.

A crimped inner tube has superior heat transfer capability because it gives turbulence to BOTH vapor and the coolant (water). This removed heat much faster for a given length. What this means is that Liebigs can be made shorter than usual, which reduces build costs while maintaining efficiency. Yours (450mm) is plenty for the still design you have chosen.

No argument about the effectiveness and efficiency of a crimped tube heat exchanger. The main reason I would not go for a crimped tube is that using vinegar/lees to clean it removes the patina. I do not know how important the patina is, but many old timers seem to think it is worth keeping. Obviously you don't think it is important.

It is fairly easy to generate turbulence in the coolant flow by creating some rough spots in the water jacket, maybe with a few bits of copper off cuts soldered onto the outside of the inner tube at random places, or something like this (if it works, gonna try it in the next day or two).

[Dnderhead]

The patina helps prevent the "copper penny" taste . first time you can clean with vinegar, but after that use water. that is all you need,
the patina is most important after the column (condenser, and connecting copper pipes)

[eskymo]

Learning all the time! I'll post some (correct size) pics when the thing is up and running. Hopefully some input/output notes as well. By accident, I managed to build my last LM with all things sweet, no hiccups at all, and capable of 96+% @ 20c. Well, here's hoping It'll happen again. I confess to not being able to grasp the intricacy of VM yet, but I'm loving it!

[punkin]

Use a union to connect your liebeg, then all you need for stripping is a short up pipe, an elbow and another union to hook the liebeg to. (makes a very basic potstill)

That's how i think it should be...

You'll have to imagine the liebig as it's not in the photo's...









ItNeverthelessExistsPunkin

[eskymo]

Thanks Punkin, I reckon I'll be able to knock one up... Just sold my old LM, otherwise I could've used that for stripping. Looks like I'll end up with TWO new toys! Life's hard aint it! Just found out the rental cost of oxy/acet bottles! Ouch! And they don't even let ya keep the bottles at that price! Call me cheap, but forget it! Anyone used MAPP gas & torch for 2" copper?

[eskymo]

Update: I finally finished the column etc. Will test it next week, with 3 different drop-lengths to the liebig. My workmanship leaves a lot to be desired, but nothing leaks!

300mm..jpg (4.6 KiB) Viewed 3938 times

[xx7777xx]

Lookin good eskymo. 2 questions that I can't answer from looking at your picture:

1.) Wanted to make sure you have not completed sealed the top where the reflux condenser is, and have allowed for venting to the atmosphere.
2.) Where is your thermometer located?

[eskymo]

Thanks xx! I remembered the warnings about venting, so I left the top of the condenser uncapped, just brazed a bar across the coil to keep the connections steady. It can't really be seen in the pic, but the thermo spiggot is right on the junction between the up-pipe and the outtake. I brazed a bit of 1/4" tube to slot the thermometer in. Will try it all out this next week, and see what happens. If y'all see a big mushroom cloud hangin' over SE Queensland, it may be a bad result.

[rad14701]

eskymo, you could probably increase the size of that picture to about 50k or 640 x 480 without causing loading issues... Looks good, what I can see of it...

[evilpsych]

Punkin.. i gotta ask. What the hell is that flux you use that looks purple/black (or like a bird shit all over your joints) its been buggin me lately. Some o the new guys might think that washing the flux residue out isnt necessary..

That said, does 3" copper grow on trees in oz? It sure looks like it catches on fire!

[punkin]

It's a Tenacity flux for brazing silver solder.

The only flux you'll see in that picture is where the stainless is soldered to the copper. I don't use flux at all just soldering copper to copper, it flows in a better fashion with out it and stays where it's put better.
The stuff that looks like birdshit is copper that's been heated and freeflowing silversolder. Not soft solder that's nice and neat and stays in the joint.

Being also that i don't give a rats arse what the equipment looks like when it's shiney, i don't try and wipe excess solder off or clean up in any way besides a wash down wiith cold water.




Works just brilliantly and i never test my joints for leaks.








I'veDoneThousandsOfBrazedJointsLikeThosePunkin

[alkoholics]

question for anyone were i put the red line, how does the vapor make its way to coming out is there a piece that the vapor collects on and rolls out to the collection plate this is basicaly what i dont get ???????

[rad14701]

alkoholics, think vapor, as in Vapor Management... The vapor path splits in the T and part of the vapor heads over into the take off condenser path... You aren't dealing with liquid or it would be a Liquid Management still... If you were controlling things with coolant then it would be a Coolant Management still...

With the design you have illustrated anything that condenses in the "reflux condenser" heads back down the column for reboiling... Only a portion of the rising vapor gets split off at the T and the rest continues up to condense as reflux...

[evilpsych]

yeah. By that definition though, could you consider a well designed VM still to have similar characteristics to a tall packed column, pot-still run extremely slowly - but with higher output rate...?? I'm still trying to grasp the concept myself.