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Vapour management still plan

PostPosted: Tue Oct 14, 2014 7:57 am
by StillSober
Here's my still plan.
The design is subject to change, however I've made the following steps:
-The SS stock pot and dog bowl and gasket I have on hand.
-The Liebig has been put together with copper from Bunnings.
-I have a 2000W step controllable (200W steps) induction portable cooker plate for this.
-I have a nice digital thermometer which will be inserted in the column near the outlet gate.

The idea of the aperture is to provide a minimum reflux ratio of around 70% (with reflux condenser water flowing) up to over 90% by closing the gate somewhat.
The column will be loosely filled with stainless steel scrubbing pads for packing.
reflux still1small.jpg

Re: Vapour management still plan

PostPosted: Tue Oct 14, 2014 8:10 am
by Zak Griffin
I'm not too sure about the intricacies of VM design, but I will suggest that you use structured copper packing instead of stainless, and that you use a 2" triclamp union instead of the bolt on job so that you can clamp it straight on to a keg when you realize that the 15L pot is too small :)

Re: Vapour management still plan

PostPosted: Tue Oct 14, 2014 8:16 am
by StillSober
What does one use for "structured copper"?
I've had a look at the tri clamp pipe hardware, it looks nice to use. If the bottom of the column has a ferule to clamp it, what does one fit to the boiler to clamp it to?

Re: Vapour management still plan

PostPosted: Tue Oct 14, 2014 8:20 am
by Zak Griffin
You'd weld a ferrule to the boiler as well mate. Or if you use a keg, clamp the column straight to the existing ferrule on the keg.

Mac has structured copper packing available in the FSD store.

Re: Vapour management still plan

PostPosted: Tue Oct 14, 2014 10:20 am
by Meatheadinc
Your diagram looks good.

one thing often missed with a VM is horizontal distance between leigberg and column should not exceed 3 time column diameter, ( eg 2.5* 3 =7.5) This will aid in the siphon effect created by vapour collapse and will lower/stop the automatic shut down VM experience ( my first VM had approx. 12" on 2" column and would not produce effectively below 65%) current setup is 2" column, horizontal dist. approx. 6" and will pull down to approx 25% (it will actually pull water too however it is a slow rate).

depending on the product you wish to make (shorter horizontal will aid in flavoured drinks as you can pull lower abv) you can vary the spacing.

Re: Vapour management still plan

PostPosted: Tue Oct 14, 2014 10:26 am
by Meatheadinc
but then again for flavoured drinks unpack the column open the valve and cap the top.. pot still time.

Re: Vapour management still plan

PostPosted: Tue Oct 14, 2014 12:12 pm
by StillSober
I was thinking because the boiler will only be able to handle 10 or 12ltr at time I could do 2 quick stripping runs (from a 25ltr ferment).
The resulting distillate would fit in a single reflux run (assuming 50% reduction in volume after the stripping runs).
I'd plan to have no reflux cooling and the gate fully open on the stripping runs. Then on the reflux run (obviously cooling the reflux condenser), I'd have the gate opened enough to achieve reasonable purity, at a reasonable rate of production.

So in this scenario am I best to keep the horizontal shortish say 100mm measured from the column to the elbow attached to the Liebig?

I can see why experienced players would simply opt for a bigger boiler, but I need experience just playing around with this stuff!

Re: Vapour management still plan

PostPosted: Tue Oct 14, 2014 1:14 pm
by Sam.
StillSober wrote:(assuming 50% reduction in volume after the stripping runs).


It will be closer to a 80% reduction.

StillSober wrote:I'd plan to have no reflux cooling and the gate fully open on the stripping runs. Then on the reflux run (obviously cooling the reflux condenser), I'd have the gate opened enough to achieve reasonable purity, at a reasonable rate of production.


Just remember you need to have the top of the still open to the atmosphere when running as a reflux otherwise if you turn your valve all the way you will pressurise your still which is very bad.

When in pot mode you will need to cap the top somehow :handgestures-thumbupleft:

Re: Vapour management still plan

PostPosted: Tue Oct 14, 2014 1:20 pm
by Zak Griffin
You'll also want to remove the valve (for pot mode) so that you don't have any chance of accidentally creating a bomb :)

Re: Vapour management still plan

PostPosted: Tue Oct 14, 2014 3:55 pm
by StillSober
Would a 19mm hole with a cork in it do the trick? (I'm presuming the cork would pop if there was any significant pressure...)

Re: Vapour management still plan

PostPosted: Mon Jan 26, 2015 6:59 pm
by Hari
Meatheadinc wrote:Your diagram looks good.

one thing often missed with a VM is horizontal distance between leigberg and column should not exceed 3 time column diameter, ( eg 2.5* 3 =7.5) This will aid in the siphon effect created by vapour collapse and will lower/stop the automatic shut down VM experience ( my first VM had approx. 12" on 2" column and would not produce effectively below 65%) current setup is 2" column, horizontal dist. approx. 6" and will pull down to approx 25% (it will actually pull water too however it is a slow rate).

depending on the product you wish to make (shorter horizontal will aid in flavoured drinks as you can pull lower abv) you can vary the spacing.



Hi Meatheadinc,
From all my experience I read the above quote with great interest. I have a 2" VM with about 10.5" centre to centre or 9" from side to side. I often have issues with siphoning, ie the output rate increases without warning. Some mods required. Is there a reference book with these recommended dimension ratios?

Re: Vapour management still plan

PostPosted: Mon Jan 26, 2015 7:41 pm
by benpandaae86
Can a vm still be made with a 200mm shootgun condensor instead of the coil ???

I was thinkin of knockin up a 3" vm with a shotty up top instead of coil

Re: Vapour management still plan

PostPosted: Mon Jan 26, 2015 7:43 pm
by Meatheadinc
Hi Hari

don't remember were it was from, but I do remember that for optimum performance, the horizontal length should not exceed 3 times the column diameter with the valve within the first 1/3
I will dig around and try and find reference.

Where is you valve positioned ?

Re: Vapour management still plan

PostPosted: Mon Jan 26, 2015 7:48 pm
by Meatheadinc
benpandaae86 wrote:Can a vm still be made with a 200mm shootgun condensor instead of the coil ???


providing there is enough surface area, any configuration will work, Eg. provide full reflux

Re: Vapour management still plan

PostPosted: Mon Jan 26, 2015 7:52 pm
by Meatheadinc
Hari
whats your take off diameter ?
condenser diameter ?
and where if any are your diameter reductions if any?

Re: Vapour management still plan

PostPosted: Mon Jan 26, 2015 7:52 pm
by Sam.
Meatheadinc wrote:
benpandaae86 wrote:Can a vm still be made with a 200mm shootgun condensor instead of the coil ???


providing there is enough surface area, any configuration will work, Eg. provide full reflux


Coils inherently have a higher surface area ;-)

Re: Vapour management still plan

PostPosted: Mon Jan 26, 2015 8:37 pm
by Hari
Here is a picture of my column still. Thanks for the quick replies guys. Happy Oz day.

Take off arm is one inch diameter, valve is lever type with a 1/2" diameter throat. Condenser is 1" tube with a 1& 1/2" outer, liebert type condenser 600mm ie 2' long.
regards Duncan
IMG_0476s.jpg
See if this makes sense guys. Not the greatest pic. Any questions?

Re: Vapour management still plan

PostPosted: Mon Jan 26, 2015 9:31 pm
by Meatheadinc
looks ok to me
personally I would go for a gate valve for better control

VM adjustments can take a few minutes to settle, how long are you waiting between adjustments ?

Re: Vapour management still plan

PostPosted: Tue Jan 27, 2015 12:44 am
by Hari
I can have it set up where it is running well for a number of hours and then it either takes off or stops. I can leave it for hours and it changes. I have used a gate valve with the same "siphoning" effect. Shorter distance may fix the issue.

Re: Vapour management still plan

PostPosted: Tue Jan 27, 2015 10:16 am
by Meatheadinc
Hari

Still trying to dig up my old VM reference stuff, ( reasearched in 2011) sorry may take me awhile.

a VM does generally stop production ( pending efficiency % varies ) which is one off there strengths,

Could your column be flooding - liquid climbs to VM branch then syphon down condenser increasing flow ??

How tight is the packing. ?