skow69 wrote:
Hot alcohol vapor does not rise. It is heavier than air. That is what makes a VM work. You absolutely do want to condense everything that gets to the RC.
Now see, I didn't know that! I was wondering what was going on. Yes, I was just using water alone. Thanks for the heads up.
This is why we harp on folks to do ample research into the theories and fundamentals... You're fumbling along without knowing How and Why the design you are building works... It's never too late to do some research... Hint...!!!
lampshade wrote:How do you prime a VM so that vapor goes down to the PC?
Currently, I run LM, because I cannot get any product out of the PC (on the VM path). I'm thinking that maybe the trick is in how much cooling water I apply to the RC, which I run so that the return water is cool and not hot.
If I make another VM/LM still, I think it might be more efficient to put the 1" valve not on the VM path, but, instead, on the reflux path, which might force vapor into the VM path.
Mine does.
The column is 2" with a 2x1-1/2 DWV tee. The LM reduces to a 1" concentric throat and the 1-1/2 side branch reduces to a 1" ball valve. So, I get reflux and VM takeoff if the valve is open (or modulated). The concentric is such an efficient reflux condenser that it compensates for the 2" to 1" reductions easily. With the LM valve closed (off of the concentric liquid collection cup) the reflux simply spills over the cup and back down the column center. The VM runs steady until the tails when it almost shuts off the flow. But it does compress them to the point that there isn't much alcohol left in the stream.
I guess it's all about the size and reflux ratios being balanced LM to VM.
lampshade wrote:How do you prime a VM so that vapor goes down to the PC?
Mine does.
Mine does not, for some reason.
I am asking if there is a way to start (coax) the ethanol vapor to go down the VM path. It seems to me, that for ethanol vapor to travel down the VM path, instead of the reflux path, that some back pressure must be introduced into the reflux path. Maybe, for most successful VM stills, that that back pressure is introduced by the falling reflux liquid. On the other hand, a powerful reflux condenser might introduce a vacuum that keeps the ethanol vapor rising into it. If that is the case, maybe VM action can be started by temporarily shutting down the reflux condenser (stop the cooling water).
I think once it is started, some of the ethanol vapor will continue down the VM path due to a chimney effect.
Last edited by lampshade on Sat Apr 11, 2015 3:15 pm, edited 1 time in total.
In Flanders fields the poppies blow * Between the crosses, row on row, * We are the Dead. Short days ago * We lived, felt dawn, saw sunset glow, * Loved and were loved, and now we lie * In Flanders fields. -- from a WWI poem
Lampshade..you do have a vent at the top of the Rc..or?
There is no such thing as a chimney effect.
There can be no vacuum,sucking or the like in a system open to atmosphere.
IF there WAS any sucktion in the VM arm (Liebig) the vapor traveling up the column would immediatly counter that.
In Flanders fields the poppies blow * Between the crosses, row on row, * We are the Dead. Short days ago * We lived, felt dawn, saw sunset glow, * Loved and were loved, and now we lie * In Flanders fields. -- from a WWI poem
still_stirrin wrote:
Lampshade, can you open a separate thread? I don't want to hijack Swag's thread too far here.
I suspect we've got some discussions regarding your still design and the performance (corrections).
ss
Done... it is in the column builds forum and titled "VM path is not working."
In Flanders fields the poppies blow * Between the crosses, row on row, * We are the Dead. Short days ago * We lived, felt dawn, saw sunset glow, * Loved and were loved, and now we lie * In Flanders fields. -- from a WWI poem
rad14701 wrote:
This is why we harp on folks to do ample research into the theories and fundamentals... You're fumbling along without knowing How and Why the design you are building works... It's never too late to do some research... Hint...!!!
I've been experimenting with condensers, not the theory behind VM design. I have done research and have had a fair amount of experience with condensers and condensation, so I don't feel that I have neglected doing my homework in that regard. I do admit I missed a crucial detail about alcohol vapor, but it makes no difference in what I have posted.
Swag wrote:Got the fittings in the mail today so I decided to solder it up. I tested the inner tube for leaks before I did and it was dry. The condenser itself, without the fittings on the end is 21". I think I could have made it shorter, but I fit it to the piece of 1.5" scrap I had.
I'll finish it up with the water fittings after work tomorrow.
(The goofy color is due to the lighting)
If this works good, I may make a reflux condenser with a 1" inner pipe and a 2" jacket. I may even try making a jacket out of ABS or PVC, since copper is so bloody expensive!
Cheers,
Could you or someone please tell me where I can order those 2x1x1 ruducing tees at? I cannot seem to find a place I can order them from. Any information is greatly appreciated.
Amazon, most big box hardware stores. Google copper reduction tee’s.
On a side note thanks for reviving this old post somehow I missed it back in 2015.
A bit of an old post.
However, don't go the plastic way with that jacket.
It will give you nothing but problems and grief.
Synthetic material and copper have different expansion numbers regarding heat.
Furthermore, the glue used for it will add to the problem.
If copper seems too expensive for you, use a 2" stainless steel pipe. It will do with the normal solder you use for copper, as long as you keep GOOD cleaning in mind.
Scott817 wrote:Thank you for the replies. I have only found it 1 place so far for $26 each but I will continue my search and I am all copper on this project
Can you pound copper pipe flat? If so, flatten a couple of pieces and solder to the end of your 2". Then, with a hole in the center for your outlet, solder a piece of pipe into the hole. Clean and flux and solder as you normally would. If you need to add strength to the solder joint, wrap once with a piece of 14 gage copper wire (from electrical Romex). The solder will wick into the wire and close and seal the joint, making it much stronger than a single copper to copper solder joint.
Similarly, solder a short piece of pipe to the water jacket inlet and outlet. From there, you can add an adapter to connect to the hoses. You don't need to spend big bucks to build if you're creative.
ss
Scott817 wrote:Thank you for the replies. I have only found it 1 place so far for $26 each but I will continue my search and I am all copper on this project
Can you pound copper pipe flat? If so, flatten a couple of pieces and solder to the end of your 2". Then, with a hole in the center for your outlet, solder a piece of pipe into the hole. Clean and flux and solder as you normally would. If you need to add strength to the solder joint, wrap once with a piece of 14 gage copper wire (from electrical Romex). The solder will wick into the wire and close and seal the joint, making it much stronger than a single copper to copper solder joint.
Similarly, solder a short piece of pipe to the water jacket inlet and outlet. From there, you can add an adapter to connect to the hoses. You don't need to spend big bucks to build if you're creative.
ss
I continued Swags model theory but with a 1" inch pipe and 12 angeled cross drilled 3/8" sections of pipe. I found the end caps locally much better priced but did do a little work capping the ports with a piece of flattened and shaped copper pipe like you suggested. I think its going to work really well. I need to make up some sugar wash to test it out. I considered making a build thread about it but might after I test it out and see the results.
I think its going to work really well. I need to make up some sugar wash to test it out. I considered making a build thread about it but might after I test it out and see the results. 