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Air cooled VM still
Posted: Thu Nov 19, 2009 4:23 pm
by nwvapors
I am building a VM still. 2" packed column 48" long, 1" take off at the head and I am interested in an air cooled reflux condenser.
I have seen finned copper tubes in plans and pictures but how do you go about calculating the size and number of these finned tubes
you will need? What angle do you place them at? My boiler is a converted 1/4 barrel keg modified to work as a double boiler, heat
source is a 2400w hot plate. Any info would be greatly appreciated.
Re: Air cooled VM still
Posted: Fri Nov 20, 2009 6:27 am
by rad14701
Greetings, nmvapors...
I don't think many folks do much with air cooling although it is definitely intriguing... While there are some calculations for air cooling theory on the parent site I'm not sure how accurate they are in practical application... Essentially, you'll need enough vapor area and cooling capacity to knock down that 2400 watts of heat you'll potentially throw at it... Whether you use convection cooling or use a fan will make a difference in required cooling area...
I've entertained the idea of splitting the vapor into four or more short finned tubes mounted at a low angle and using a fan to keep a large air volume moving over them... Current circumstances have kept me from experimenting, however... I'm still interested in the concept just the same...
Perhaps one of out members with HVAC experience can chime in with some numbers...
Re: Air cooled VM still
Posted: Fri Nov 20, 2009 6:58 am
by HookLine
Try a Google search for "air cooled condenser".
This has some pretty technical stuff on air cooling.
http://www.chemstations.com/content/doc ... nual56.pdf" onclick="window.open(this.href);return false;" rel="nofollow
Re: Air cooled VM still
Posted: Fri Nov 20, 2009 7:06 am
by HookLine
If you go to this page (you have to join the forum to access it)
http://groups.yahoo.com/group/Distillers/files/" onclick="window.open(this.href);return false;" rel="nofollow
you will find a document called
'Easy Air-Cooled Condenser Calculation
' by aborza
Re: Air cooled VM still
Posted: Fri Nov 20, 2009 12:53 pm
by nwvapors
Thanks guys, I'll check out those links. I'll let you know what I find out.
Re: Air cooled VM still
Posted: Fri Nov 20, 2009 7:50 pm
by HookLine
nwvapors wrote:I'll let you know what I find out.
Please do.
Cheers
Re: Air cooled VM still
Posted: Sat Nov 21, 2009 3:45 pm
by nwvapors
Hey Rad14701,
Roughly what angle were you thinking of running your cooling tubes?
I was thinking about 30deg or so. I have found a few co.s that sell
hydronic baseboard heaters, you can get a 2' model for under $20.00
and rob the finned copper element out of it. There is also a co.,
Wolverine Tube Inc., that sells finned condenser tubing that is also
spirally grooved on the inside for turbulence. I haven't placed an inquiry
on that yet, I am sure it won't be cheap and I don't know what a
minimum order would be. Still peckin' away at it.

Re: Air cooled VM still
Posted: Sat Nov 21, 2009 4:46 pm
by rad14701
Between 30 and 45 degrees off horizontal was what I was thinking - closer to 30 degrees...
Re: Air cooled VM still
Posted: Mon Dec 14, 2009 11:21 am
by nwvapors
Hello,
Is there a calculator within this site that will let me compute the energy my still is using at the condenser? I have been "talking" to a gentleman named Riku. He claims air-cooled reflux is quite obtainable using hydronic heater tubing. I need to however figure out the energy production at the reflux condenser in order to counter it with enough cooling from the finned copper tubes.
Slainte,
Kevin
Re: Air cooled VM still
Posted: Thu Dec 17, 2009 11:10 am
by nwvapors
Hookline,
I tried to access the the post by Aborza on yahoo distillers site and It either doesn't exist anymore or it has been renamed. I did find a lengthy discussion of calculations being made and a formula somewhere but I can't find it. I will go back and hammer at it some more but in the mean time if you find a working link can you forward it to me? Much appreciated.
Slainte,
Kevin
Re: Air cooled VM still
Posted: Thu Dec 17, 2009 11:23 am
by nwvapors
Hookline,
I found it, thanks, I'll see what I can figure out.
Slainte,
Kevin