Converting Reflux VM Still to CM

[eyendall]

have been running a reflux VM still for several years. Now it needs to be
reconditioned or modified. I've been reading about the CM approach but am
having difficulty grasping from the still pictures how this would differ
either in hardware, condenser sizes and locations, or basic operations from
what I have now. The only difference I can see is that the reflux VM is
initially run with the ball valve closed while the CCVM still is run from
the start with uninterrupted flow to the liebig. If that is the case then the only
control that could be exercised would be by either varying the heat or
varying the water supply. The first is easy enough and I do it now when running in pot still mode but how do you achieve
the second? Currently I feed the cooling water separately to the reflux and
product condensers using two aquarium pumps which offer no flow controls.
What would I need to do differently for CM operation??

My current still has a 48in x 2in column to the ball valve offtake followed
by another 18in x 2in connection. The reflux coil condenser is 14in long.
The liebig condenser has a 36in jacket with a 1/2in tube inside. Does all
this remain suitable for a CM still?

Assuming I can go ahead with this, what size offtake would be best from the
2in column? Would a reducing tee 2in to 1/2in be too weak to handle the weight of
the liebig condenser? Is there any point to retaining the ball valve and if so, how close to the column should the ball
valve be placed or does it make no difference. How long should both
condensers be, max & min?

I would very much like to see a straightforward drawing with specifications for a CM still.

Thanks for any help and advice you can offer.
Eric

[Yummyrum]

First off you are saying CM whch is a Coolant Management still which is a totally different animal than the CCVM you later mention which I think is what you want .
You control the reflux by physically lowering it or raising it past the output appurature . Otherwise the setup is the same regarding running both condensers with full coolant flow like you already do .

You must remove the valve as the advantage of a CCVM over a VM is you can run it in Pot still mode by pulling out the condeser and capping the top ...... a potential bomb if you have a valve still there .

The problem with CCVM is how the condense stays put when you move it up .That is why most have used the corrigated stainless steel coil as it will " cling " to the side whereas most of the copper wound coils don't touch the sides and rely on the top cap to hold them in place .

[kimbodious]

The problem with CCVM is how the condense stays put when you move it up .That is why most have used the corrigated stainless steel coil as it will " cling " to the side whereas most of the copper wound coils don't touch the sides and rely on the top cap to hold them in place .

You can work around this by weaving some SS scrubber through the RC coil to add a bit of ribbed friction to the fit....

[Yummyrum]

You can work around this by weaving some SS scrubber through the RC coil to add a bit of ribbed friction to the fit....

Cheers Kimbodious

[eyendall]

First off you are saying CM whch is a Coolant Management still which is a totally different animal than the CCVM you later mention which I think is what you want .
You control the reflux by physically lowering it or raising it past the output appurature . Otherwise the setup is the same regarding running both condensers with full coolant flow like you already do .

You must remove the valve as the advantage of a CCVM over a VM is you can run it in Pot still mode by pulling out the condeser and capping the top ...... a potential bomb if you have a valve still there .

The problem with CCVM is how the condense stays put when you move it up .That is why most have used the corrigated stainless steel coil as it will " cling " to the side whereas most of the copper wound coils don't touch the sides and rely on the top cap to hold them in place .

You are correct: I had thought CM and CCVM were referring to the same beast but you and Dantuss have sorted that out for me. I must say however that it seems to me that the use of a steel coil and presence or absence of a valve is more of a design than an operational difference and rather trivial. (But I may be missing something of more fundamental importance). I am not worried about keeping the valve and running the still in pot mode as I am well aware of the danger of a closed system. Thanks again for your response.

[RedwoodHillBilly]

Remember that a CCVM is a VM. The reflux coil acts as the valve as well, so you don't need or want another valve in the system. The CCVM is a very versatile still if you want to run in both reflux and pot mode. They are dead simple to build and run. If you haven't already read DAD300's post on the CCVM, I would recommend it. http://homedistiller.org/forum/viewtopi ... &p=7104768" onclick="window.open(this.href);return false;" rel="nofollow

[Dantuss]

I cant really comment about the operation of a CM or LM still as I have only run this CCVM.

I do know its very easy to use the only thing I have to keep an eye on is the temp of the cooling water as long as this temp is low enough to knock down all the vapor I'm good. I route my cooling water through the product condenser then onto the re flux condenser then back to the reservoir. I do not need to worry about varying the heat of the cooling water or the flow rate, both of these stay constant the entire run. No fiddling around.

Re flux coil knocks ALL vapor down and varying the depth of the coil in relation to the take off T controls the re flux ratio and take off rate.

Start pump keep eye on reservoir temp move coil up and it runs by itself.

One thing Dad300 insists on is that the take off side of your column T is of equal size as your column or the take off rate is greatly reduced.

Heres a link to Dad300 discussing this design. He makes some very compelling arguments.
http://homedistiller.org/forum/viewtopi ... d#p7104768

Cheers!

[Yummyrum]

You must remove the valve as the advantage of a CCVM over a VM is you can run it in Pot still mode by pulling out the condeser and capping the top ...... a potential bomb if you have a valve still there .
.

I am not worried about keeping the valve and running the still in pot mode as I am well aware of the danger of a closed system.

Glad you are aware of this .
I would strongly reommend removal of the valve though as accidents can and will happen .
Don't post any pics here with the valve in it as someone not so cluey as you may see it and copy it .
Don't pass this still on with the valve still in it .
Sorry to labour the point but five minuates work could save a life

[eyendall]

Yummyrum
Not to argue as your concern for safety first is most important but perhaps it might be expressed in a somewhat different way by focussing on the principle involved, not the hardware. The principle or rule to hammer-in is that no reflux still should ever be operated without being vented to the atmosphere. That's the way I learned it and operate by. There must be thousands of reflux stills operating now with valves. New distillers who research the internet for information might get confused and think that all previous reflux designs are obsolete and unsafe which is certainly not the case. But I don't think you meant this.
Cheers
Eric

[ShineonCrazyDiamond]

I think you're missing the point. There are reflux stills that have valves, and some that do not. The ones that have valves are constructed with alternate atmospheric releases. You are trying to combine 2 styles of reflux stills, and are making a potential bomb. Ever fill the boiler and forget the drain is open? Ever see how that COULD happen? Now see how you, or even someone less educated, could fire her up and forget that the valve is closed? Boom.

Yummy is right. If you insist on leaving the valve on in your conversion, then don't post the design here. Safety here is about what could happen, not that you know not to do it. And if you pass that still on to a rookie, that might forget to open the valve on that particular setup, then just know whatever happens is on your shoulders, as a properly designed still wouldn't allow for a catastrophe, even if someone closes a valve.

[kimbodious]

Aren't CCVM stills open to the atmosphere at the top of the column? Even if the valve was kept on the offtake and it was left closed the condensate would eventually flood over the top.

[Yummyrum]

Aren't CCVM stills open to the atmosphere at the top of the column? Even if the valve was kept on the offtake and it was left closed the condensate would eventually flood over the top.

Yes Kimbo .... you are absolutely right but a CCVM can be run as a Pot still by removing the condenser and capping the top .....now tell me where the atmosphere vent has gone ?

We have to do a risk assesment and take into concideration all possible outcomes . .... the use of a CCVM as a Pot still is a high possibilty ... I do believe you use it like this too .

[Saltbush Bill]

Ever fill the boiler and forget the drain is open? Ever see how that COULD happen?

Been there and done it more than once. Its all to easy to forget something like that.

The principle or rule to hammer-in is that no reflux still should ever be operated without being vented to the atmosphere. That's the way I learned it and operate by.

I think someone told you wrong , it should be " ANY STILL of ANY TYPE , MUST ALWAYS be open to atmosphere"
There is no place in this hobby for any still that can accidentally or otherwise become a bomb .............. including yours.

[kimbodious]

a CCVM can be run as a Pot still by removing the condenser and capping the top .....now tell me where the atmosphere vent has gone ?

We have to do a risk assesment and take into concideration all possible outcomes . .... the use of a CCVM as a Pot still is a high possibilty ... I do believe you use it like this too .

No need for a valve on a CCVM or a pot still, I don't use them. I did have a valve when I had a VM and I recall once using the head of the VM as the pot still. I blew up the outlet pipe as a final check the valve was open. I figured if I blew up myself the valve was obviously still shut. :

[kimbodious]

what size offtake would be best from the 2in column?
Eric

2", that way the vapour column will roughly split evenly between tumbling out from the offtake or continuing to be pushed up the column. Offtakes smaller in cross sectional area than the column will reduce the amount of vapour exiting that way = slower output.

My 2" CCVM systemwith a 2200w element, has a 2" offtake going to a 2" shotgun condenser, I get 1.8 litres of product per hour at 95% (temperature corrected).

[Yummyrum]

No need for a valve on a CCVM or a pot still, I don't use them.

Absolutely
You're clever than the average bear ...and I've taken this out of context for a good reason ...but ...... you are still alive
Which is the point . If you are converting from VM to CCVM ...Mind my french Get rid of the Valve