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Condenser control still

Posted: Sun Jul 11, 2010 2:50 pm
by manu de hanoi
Here's a new design, uber simple, does not require a valve (but maybe some gloves) and saves height
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and yes it works :

http://www.youtube.com/watch?v=2vJn0lp-IP0" onclick="window.open(this.href);return false;" rel="nofollow

Re: Condenser control still

Posted: Sun Jul 11, 2010 3:07 pm
by LWTCS
So simple and yet,,,, talk about being able to dial in some control.

What's the angle of the,,,,,,,,"condenser sleeve"?

Looks like 3" tubing. Is that correct?

Will you do anything to dress up the aesthetic if you get requests from potential clients?

This is fantastically direct.

This trumps the Boka for simplicity by a long shot (was that wrong to say that?).

Good for you.

ABV?

Re: Condenser control still

Posted: Sun Jul 11, 2010 3:30 pm
by kiwistiller
LWTCS wrote:ABV?
will depend on the column height and how much you're throwing at it and how much you're taking out, just like any reflux control method, right? All we do with different reflux heads is change the reflux ratio in lots of different ways...

Interesting stuff anyway manu, cheers.

Re: Condenser control still

Posted: Sun Jul 11, 2010 3:49 pm
by LWTCS
kiwistiller wrote:will depend on the column height and how much you're throwing at it and how much you're taking out,
Indeed.
I should have been more specific.

That coil looks big enough to impose it's will on a good bit of heat.

How has this particular rig performed manu?

Re: Condenser control still

Posted: Sun Jul 11, 2010 8:54 pm
by manu de hanoi
The rig performed well enough for me to be willing to keep it as my current still. The idea evolved from the reverse CM still, where I wanted something as safe in terms of vapour escape but easier to build.

Yes it's 3" tubing and yes the aesthetics would be better on a sold still (That piece of pipe has seen so many stills ! I try to recycle as much as possible for my own prototypes) .

The angle as to be close enough to the horizontal so that drops of condensate dont jump from one coil loop to the other and has to be be big enough to allow an easy flow and let the output above the column branch if you have a reducer (like in the video). The angle in the drawing should work.

The coil has to be big but in theory not bigger than a boka.
However,
the longer the coil,
the slower the coolant rate
the more control you get.
(is that a haiku ?)

Quizz: there is a small design element that I forgot to mention and without which the thing wont work well, can you find it out ?

Re: Condenser control still

Posted: Sun Jul 11, 2010 9:05 pm
by olddog
Nice simple design Manu, you could probably refine it easy enough with a lever control to move the condenser in or out.



OD

Re: Condenser control still

Posted: Sun Jul 11, 2010 9:12 pm
by manu de hanoi
olddog wrote:Nice simple design Manu, you could probably refine it easy enough with a lever control to move the condenser in or out.



OD
yes, or a handle

Re: Condenser control still

Posted: Sun Jul 11, 2010 9:26 pm
by olddog
How fine adjustment would be needed with the condenser ? your video demo shows a large movement, a movement that great may or may be not needed.


OD

Re: Condenser control still

Posted: Mon Jul 12, 2010 12:57 am
by kiwistiller
manu de hanoi wrote:Quizz: there is a small design element that I forgot to mention and without which the thing wont work well, can you find it out ?
hmm
Reflux centering?
Thermo? (guess you could use a parrot)
Vapour lock in the output tube? although that was pictured.
go on, what's the answer?

Re: Condenser control still

Posted: Mon Jul 12, 2010 1:23 am
by manu de hanoi
None of these....mmhhh let's wait 24 hours, see if someone finds out !

Re: Condenser control still

Posted: Mon Jul 12, 2010 9:11 am
by LWTCS
Any thing to do with the square tubing or the transition from square to round?

Re: Condenser control still

Posted: Mon Jul 12, 2010 9:18 am
by manu de hanoi
LWTCS wrote:Any thing to do with the square tubing or the transition from square to round?
no

Re: Condenser control still

Posted: Mon Jul 12, 2010 9:25 am
by ScottishBoy
Packing....?

Love the design, BTW. Solder one 30 deg angle and a tap and you are all done. Beautiful.

Re: Condenser control still

Posted: Mon Jul 12, 2010 9:45 am
by rad14701
My first guess...

The take off cup has to be large enough to allow for the capture all of the condensate because if the take off port was only the size of the copper line some of it would bypass the port and become reflux...

Nice concept, Manu... The same concept could be used for a VM column, thus eliminating the need for a gate valve in the take off branch... Simply drop the reflux condenser low enough to attain 100% reflux before the vapor can reach the take off branch... Raise it up just enough to maintain the preferred reflux ratio and/or product take off rate...

Re: Condenser control still

Posted: Mon Jul 12, 2010 10:46 am
by LWTCS
Rad has it,,,,,,,,,,...yes?

Re: Condenser control still

Posted: Mon Jul 12, 2010 12:17 pm
by manu de hanoi
LWTCS wrote:Rad has it,,,,,,,,,,...yes?
rad well understood the purpose of an existing feature, the cup, that you can see on the drawing and the video. A little more effort guys your are near ! If you stare long enough at the drawing u'll see it, something is wrong

Re: Condenser control still

Posted: Mon Jul 12, 2010 12:25 pm
by rad14701
Hmm... Looks like due to the speed that the reflux can potentially attain you have drastically reduced the angle of the reflux centering tab...

Re: Condenser control still

Posted: Mon Jul 12, 2010 1:33 pm
by kiwistiller
edit because I realised the thing I typed was stupid. Is it something wrong with the drawing or just a design consideration you haven't mentioned? Condenser length would be an issue if you weren't steady on both coolant flow and temp, right?

Re: Condenser control still

Posted: Mon Jul 12, 2010 3:52 pm
by LWTCS
I see the trap on your drawing but no trap in the video.

Re: Condenser control still

Posted: Mon Jul 12, 2010 9:01 pm
by MudDuck
manu de hanoi wrote: If you stare long enough at the drawing u'll see it, something is wrong
If built exactly to the drawing it looks like the condenser would be lying on the bottom of the pipe and block the flow of the condensate, there must be something in the actual still to keep the condenser raised and centered in the tube.

Re: Condenser control still

Posted: Mon Jul 12, 2010 11:44 pm
by manu de hanoi
MudDuck wrote:
manu de hanoi wrote: If you stare long enough at the drawing u'll see it, something is wrong
If built exactly to the drawing it looks like the condenser would be lying on the bottom of the pipe and block the flow of the condensate, there must be something in the actual still to keep the condenser raised and centered in the tube.
congratulations MudDuck! here it is :
PICT0655.JPG
The rail also helps sliding the condenser if you had any scars from previous builds of burrs around the cup. Remeber to make a small v shape bend downwards inside the cup so that condensate wont slide on top of the cup on the wire.
2 rails may help for more comfortable sliding action of the condenser :)

Re: Condenser control still

Posted: Tue Jul 13, 2010 12:54 am
by MudDuck
Do I get a prize? :o

Seriously though that is one nice simple design, I never would have thought of that myself.

Re: Condenser control still

Posted: Tue Jul 13, 2010 4:10 am
by ScottishBoy
Ahhhh...I was going on the assumption that you would have it raised anyway because of the way you adjust it. I was picturing a sort of microscope gear that would move it in and out...I like knobby turny things.

But correct me if Im wrong, the only way that the coil would function as a dam would be if the coil was snug with the outside wall. Any signigficant reduction in diameter would lead to limited surface contact, since it wouldnt form a clear seal Like this.
tubecooler.JPG
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( Stand back from my awesum paint skillz! The blue is exagerated for effect. The alcohol should just slip by the gap.The blue is alcohol. The blac is the cooling coil.)

I think this is right, but I would be interested to hear other folks chime in. Does it really work better? If it was flat on the bottom, wouldnt it behave sort of like a tray condenser?
( I also was not able to view the video so I could be working with less information than Im supposed to have)

PS. Just playin devil's advocate. I really like the design. Will you call it a "Manu"?

Re: Condenser control still

Posted: Tue Jul 13, 2010 4:17 am
by LWTCS
He did mention that it will work, but not as well without the track.

Re: Condenser control still

Posted: Tue Jul 13, 2010 5:34 am
by rad14701
Good guess, MudDuck...

I was actually pondering having rails attached to the condenser coil itself, as part of an adjustment mechanism... That was to be a refinement consideration as it wasn't mentioned anywhere so far...

I like this even more than the Reverse Liquid Management (RLM) designs currently being run in Europe... Simplicity at its best...

Re: Condenser control still

Posted: Tue Jul 13, 2010 7:12 am
by ScottishBoy
Hmmm...You could actually solder a piece of copper wire from romex cable right down the middle and then have it dump directly into the center like the boka plate director. Gloriously simple. Im half tempted to build one just to see how it works.

Re: Condenser control still

Posted: Tue Jul 13, 2010 3:26 pm
by scarecrow
You could stagger the coil diameters.
Larger diameter at the start, middle and end. The rest can be slightly smaller.
That way only 3 coils to impede the flow slightly rather than all of them.

scarecrow

Re: Condenser control still

Posted: Tue Jul 13, 2010 5:50 pm
by manu de hanoi
scarecrow wrote:You could stagger the coil diameters.
Larger diameter at the start, middle and end. The rest can be slightly smaller.
That way only 3 coils to impede the flow slightly rather than all of them.

scarecrow
- a cone shape would still lay on one side
- even if the first rings were supposed to "center" the coil, given the weight and flexibility of the coil it would bend. you can see on the video that 2 hands are required to hold a big coil if you dont want it to bend under it's own weight.

Re: Condenser control still

Posted: Wed Aug 04, 2010 7:44 pm
by HookLine
Very nice, Manu. Simple, easy to build and run, and cheap.

Like all CM designs it needs constant coolant temps and flow rates for stable reflux operation.

No height advantage over LM, and only a small one over VM, (a VM still has the take-off port section). The condenser in those two designs can be placed at any angle from vertical down to almost horizontal.


One suggestion:

How accurately you can control reflux ratio depends on how efficient your condenser is per unit length of overall condenser. The more efficient it is, the less distance you have to move it to change the reflux ratio a given amount. However, less distance means higher sensitivity and (potentially) less accuracy. So, this might be one design where the condenser should be less efficient, in order to get better control over reflux ratio.

Two easy ways to achieve that:

1. Single coil instead of a double (and fill the centre with mesh/scrubber). Probably not suitable for columns above 2" diameter.

2. Wider spacing between turns of the condenser coil. I usually suggest 3-6 mm, but 10 mm might be better here.

Re: Condenser control still

Posted: Wed Aug 04, 2010 8:23 pm
by rad14701
Your condenser specifications are inline with what I was thinking, HookLine... Not only the single coil with scrubber but also the increased gap between coils...

I've been pondering several mechanical methods of adjusting condenser position... Something that makes repeatability easier without being overly complex or clunky...