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First CCVM vinegar run question.

Posted: Mon Aug 07, 2017 3:52 am
by Digital_Plasma
Hi, I was performing a vinegar run for the first time on my newly build CCVM still. First some technical info.
The column (not packed or insulated yet) is 54mm (2") diameter, 1400mm (55") tall. It has a liebig condenser 15mm (19/32") diameter with a 22mm (7/8") jacket and a total length of around 600mm (23"). On top I have a triple wound condenser made of 6mm (1/4") copper tube an a total length of 170mm (6.7"). Heating is a 9.5kw gasburner.
Now to my question. While doing the cleaning run, I blocked of the top of the column, to get steam out the liebig condenser. So far so good. After 30 minutes I turned off the heat at placed the coiled condenser in the top and turned on the heat again for about 30 minutes. Afterwards I wanted to test the water flow and "knock down power". It showed to be quite effective. Maby too effective. It knocked everything down. Even at high power. As I lifted the coiled condenser up to let steam through to the liebig, nothing happend. Or at least very little happend. Is this normal with water/vinegar run or is the coiled condenser to powerful?
Cheers.

Re: First CCVM vinegar run question.

Posted: Mon Aug 07, 2017 4:04 am
by Digital_Plasma
It might be that with packing and insulation it makes all the difference. But I might have to make the top of the column taller?

Re: First CCVM vinegar run question.

Posted: Mon Aug 07, 2017 4:54 am
by Klein
When you raised the coil, was it still blocking the path to the Liebig?

Re: First CCVM vinegar run question.

Posted: Mon Aug 07, 2017 4:59 am
by Klein
Also what is the size of the takeoff? Is it a 2" tee (1:1)

Re: First CCVM vinegar run question.

Posted: Mon Aug 07, 2017 5:29 am
by Digital_Plasma
Klein wrote:Also what is the size of the takeoff? Is it a 2" tee (1:1)
The takeoff is 2" to 1.5" to 1/2".
20170807_152736.jpg
As you can see in the image, it's not the access to the liebig that's restricted, but the top of the column.

Re: First CCVM vinegar run question.

Posted: Mon Aug 07, 2017 6:01 am
by still_stirrin
Perhaps a longer column extension above the Tee would help.

It looks like you need to raise the coil more to open up the branch of the Tee to vapor flow (better). As it looks now, when the coil is inserted into the top of the Tee, it likely still blocks most, if not all of the branch line. Raising the coil more will allow more vapor to pass without venting above the column...which could happen when you simply raise the coil above the top of the Tee (and column).

Remember, any vapor that goes above the Tee branch MUST be knocked down (condensed).
ss

edited to add - Also, the coil looks to be quite tightly wrapped. When the vapor hits it, it contacts the surface of the coil and will condense quickly, especially if the coolant is cold. It behaves almost like a "closed valve" as far as passing vapors. So again, if the coil covers the Tee branch even partially, it will significantly reduce or cutoff vapor flow. A looser wound coil would allow for some gradient of heat transfer, possibly allowing some vapor to pass a partially blocked branch line.

Re: First CCVM vinegar run question.

Posted: Mon Aug 07, 2017 8:12 am
by OtisT
Hi Digital Plasma. Vapor and liquid like to flow to the path of least resistsnce. One thing I have observed is that Alcohol Vapor is heavier than air, and Water Vapor is lighter than air. So, if you remove the reflux condenser and leave the top of your column open, water vapor will want to escape out the top and will only fill your product condenser if the top path is restricted. If it were Alcohol vapor, the vapor would first fill your vapor port ( to your product condenser), and the excess vapor would go up and out the top.

Good luck.

Re: First CCVM vinegar run question.

Posted: Mon Aug 07, 2017 11:03 am
by Digital_Plasma
Thanks for some very useful information. I'll make some changes and make an column extension and see what difference it makes.

Re: First CCVM vinegar run question.

Posted: Mon Aug 07, 2017 6:29 pm
by Skipper1953
With regard to the column extension, you want to have the reflux condenser fully enclosed in the column even when the take off port is wide open. That way, any vapor rising into the reflux condenser must contact the entire coil before it can exit the column.

Re: First CCVM vinegar run question.

Posted: Tue Aug 08, 2017 3:14 am
by kimbodious
Nice looking still! :thumbup: I have a CCVM. It will run differently with ethanol vapour; it is heavier than water vapour and some will find the offtake and run down to the product condenser. You will need an extension above the offtake, as others have said, to make sure there is a reasonable opportunity for the rising component of the ethanol vapour to come in to contact with the reflux condenser coils.

Watch for flooding the offtake with condensate. Make sure you have a 4" or more gap between the top of your packing and the bottom edge of the offtake. Your CCVM should make near azeotrope ABV quite readily. If you're struggling to get above 90% try reducing the boil just in case the reason is that you are flooding the offtake with lower ABV condensate (no guesses how I learned this - doh :oops: )

Re: First CCVM vinegar run question.

Posted: Tue Aug 08, 2017 11:57 pm
by Digital_Plasma
kimbodious wrote:Nice looking still! :thumbup: I have a CCVM. It will run differently with ethanol vapour; it is heavier than water vapour and some will find the offtake and run down to the product condenser. You will need an extension above the offtake, as others have said, to make sure there is a reasonable opportunity for the rising component of the ethanol vapour to come in to contact with the reflux condenser coils.

Watch for flooding the offtake with condensate. Make sure you have a 4" or more gap between the top of your packing and the bottom edge of the offtake. Your CCVM should make near azeotrope ABV quite readily. If you're struggling to get above 90% try reducing the boil just in case the reason is that you are flooding the offtake with lower ABV condensate (no guesses how I learned this - doh :oops: )
Thanks. :) I'll post some more pictures in a separate topic, when I get I working properly. If the coil condenser is proven to be troublesome, I'll change it. But for now, I'm gonna make the column extension and run a sacrificial sugar wash through the system at see how it performs. :)

Re: First CCVM vinegar run question.

Posted: Wed Aug 09, 2017 8:16 am
by bluefish_dist
You really have to throw a lot of power to a vm for it to distill any water. That is part of the appeal of the design, it slows down when there is no alcohol.
I would do an alcohol cleaning run and see how it works before doing a redesign.