Newbee question Foreshot, Heads, Body or heart and tails

Vapor, Liquid or Cooling Management. Flutes, plates, etc.

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punkin
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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by punkin » Thu May 07, 2009 12:58 am

Yes, your numbers add up.

With practice and bleeding heads slower, you'll get that portion lower.

adding bicarb (and water) before the run may help.

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by FREAK! » Sat May 09, 2009 12:39 am

Thanks Punkin
I read that section about adding salt and or Bi-carb and I have to say it all went right over the top of my head, but I will defiantly give it a go on my next sprit run.
Here is the finished still, all insulated and set up for a stripping run. Undo the ferrel clamp on the top of the boiler and the column can be put in place.
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HookLine
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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by HookLine » Sat May 09, 2009 1:29 am

Nice work. Look forward to the results.

Be safe.

Have fun.

8)
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And have fun.

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by FREAK! » Tue May 12, 2009 4:28 pm

snuffy wrote:Very nice.

I can see there isn't room for adding a valve. Maybe on the next rev? With a valve that would allow reflux to pool in the bottom of the slant tee, it could function as a heads reservoir.

A+
Hi Snuffy, thanks for the A+
I have see a couple of references to a technique you use to compress the “heads” part of a spirit run by using a low energy input to the wash and minimal reflux, I am very interested in this. I am using an emersed electric element and I have a power controller.

Because I can watch the amount of reflux being returned to the column and can see the changes to this flow as changes are made to the power input I think my still would be well suited to your technique.

Could you give me a rundown on technique please :D



Side question to all if I may:
I have taken Punkin’s advice and looked a lot more closely at using bi-carb soda in the low wines before the spirit run. From all I could find to read there are large fluctuations in the amount required to do the job, I have see reference to everything from 12g up to 48g per Lt of pure alcohol and also the length of time the low wines should sit on the bi-carb soda before going for the spirit run, time frames of days to months are mentioned.
I am going with 20g bi-carb for every 1lt theoretical pure alcohol (20g goes into 2lt of 50% striped) and it will sit on the bi-carb for a minimum of 1 week, am I in the ball park of what others are doing???

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by HookLine » Tue May 12, 2009 4:37 pm

I use 1 teaspoon of sodium carbonate per litre of low wines, or 1 spoon of sodium bicarbonate per litre. With bicarb you need to wait at least 3-4 days before running it, with carb you can run it straight away.
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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by snuffy » Wed May 13, 2009 8:57 pm

It's well known that heads have to be taken off a column very slowly. Too much vapor going up and condensate going down tends to spread the heads through the column. If you read enough of the posts here, you will find there was discussion of the concept of "over-refluxing." This meant running the column too hard - too much heat, too fast a vapor velocity.

With liquid management (LM) distillation heads, the reflux rate is controlled by the valve that drains off liquid before it returns to the column. Vapor management (VM) regulates the reflux rate by drawing off vapor before it reaches the reflux condenser. In either of these systems, barely cracking the valve will allow a very high reflux percentage to return to the column, thus keeping it in thermal equilibrium. People noticed that even when the valve setting was very low and the amount of product being removed was small that the ability to separate the heads into a small volume varied a great deal.

Two possible variables came under consideration: time to equilibriate and the amount of power being fed to the boiler. Some people opted for a very long period of equilibriation as a means of getting the substances with a boiling point lower than ethanol to concentrate (compress) in the upper part of the column. Others found that a shorter period would suffice if the boiler operated gently. Riku, in his splendid book on automatic stills, described a way of trapping the volatiles in the upper part of the column.

A further clue was provided when a link to a Japanese research paper pointed out that there is an azeotrope of ethanol and ethyl acetate with a boiling point of 71C. Ethyl acetate is one of the major components of heads, the others being acetaldehyde and methanol. Methanol forms azeotropes with several of the higher alcohols found in the tails, so it has concentration peaks in both the heads and the tails, as well as being present throughout the hearts in a lower concentration.

All of these things together suggested that the heads were being spread out in the column by some mechanism. I hypothesized that it was physical mixing by the return of the reflux condensate down the column "pulling" the heads downward. So I thought that by minimizing the amount of reflux while maintaining a high reflux ratio, the heads could be reduced to the smallest volume. The way to do this is to use just enough power to the boiler to maintain reflux and equilibriate at this power level. My glass column allowed me to observe the reflux in the column and I was astounded at how little heat was necessary. In a 48" x 1 3/4" column with a 1 1/4" VM head, I get a satisfactory reflux with 150W.

When this happens, the temperature at the top of the column can equilbriate as low as 74-76 deg C. This is considerably below the vapor temperature of the alcohol-water azeotrope, thus demonstrating that the heads have concentrated at the top of the column. The amount of ethyl acetate is too small to get it down to 71 C, but it will go lower than alcohol.

I've adopted a rule of thumb of equalizing for twice the amount of time needed to stabilize the column. If it takes ten minutes for the temp to drop to a stable level below 78 C, then I hold it for an additional ten minutes before starting to draw off the heads. The temperature at the top of the column will slowly rise to 78 deg C as the heads are removed. During this time, I slowly increase the power to the boiler to clear the last of the heads.

Once into the hearts, I increase the power to give a vapor velocity of 15 - 18 inches/sec. 20 ips is generally regarded as the fastest rate that will produce good separation. I have found that I can't push my column that fast. At this rate, the temperature will hold steady as a rock at 78.0 C. When it rises, the tails are beginning. If you leave the VM valve alone, the output will diminish as the temperature rises.

So there's really not much new to this method. Easy does it has always been the rule for making anything good. The explanation is a little more detailed than before, but the method of gentle separation of heads has been known as long as there's been distilling.

One thing I should point out: the resolution and the accuracy of digital thermometers are very different things. Most digital thermometers display in tenths of a degree but are only accurate to 1 deg C. Calibrate or just rely on relative readings. Equilibriate to as low a temperature as you can.
Time's a wasting!!!

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by rad14701 » Thu May 14, 2009 5:39 am

Great explanation, snuffy... I'll have to give this a go with my LM column to see if it makes a difference... I'll need to source out a new digital thermometer first, however, because the cheap model I have only displays .1 degree changes at lower temperatures and then switches to .5 increments up where they are most important for distillation...

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by HookLine » Thu May 14, 2009 6:31 am

Thanks for that, Snuffy.
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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by snuffy » Thu May 14, 2009 8:13 am

The best digital thermometers I've found are from Vernier Scientific. They are USB, so you have to have a computer hooked up to them. They are accurate to 0.1 C and can be calibrated. About $50.00 US with shipping.

http://www.vernier.com/go/gotemp.html" onclick="window.open(this.href);return false;" rel="nofollow
Time's a wasting!!!

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by FREAK! » Thu May 14, 2009 4:47 pm

Fantastic explanation!!! Even got through my thick head, (had to read it 3 times though) and as always when something is explained this well it just makes sense.

Basically, if I have got it right, you can reflux all you like but if you are pushing the column too hard by forcing the vapor to hard in one direction and having too much liquid running back in the other all I am doing is overpowering some or most of the theoretical plates I have worked so hard to put in the column in the first place.

I agree 100% about the accuracy of thermometers, I use a lot of measuring and testing equipment in my line of work and we use a basic rule that says for true accuracy use one less decimal point that the instrument says it can do. Some micrometers have scales on them that go down to 0.001mm but are really only accurate to 0.01mm and that’s in the hands of a skilled operator. I use a remote digital thermometer for the stripping runs but use a Pyrometer (from work) for my spirit runs. The pyrometer says it can measure 0.01 degree C increments.

My next spirit run I will get the power as low as I can while maintaining 2 drops per second in the reflux viewing chamber, let it settle and then see if I can take the heads off at one drip per second or a bit less.
I think that is in keeping with you post above.


Thanks again for you complete, in-depth explanation. Brilliant!!!!

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by Ayay » Fri May 15, 2009 12:39 am

Snuffy your explanation is an eye-opener. I've noticed condensates coming out the pot still before the pipes are warmed up... so there are some highly volatile early arrivals that a reflux column will recycle into the general mix if things are going too fast. I will be trying what you and others have found out.
cornflakes...stripped and refluxed

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by schnell » Wed May 20, 2009 3:26 pm

You can look up charts of azeotropes in an old CRC Handbook of Chemistry and Physics. I have an old one from the 1970's that has proved it's worth time and time again.

They have accumulated the painstaking work of thousands of documented experiments to build these tables of physical properties. The azeotrope charts have a wide variety of binary and trinary mixtures. If you look up specifically ethanol:water, ethanol:ethyl acetate, etc. your understanding of distilling will probably go up an order of magnitude after looking it over.

My favorite part? Pressure changes the ratios.

Most of you hope to get 95.6% someday. (If you're at sea level.) My vacuum stills can run 99.5% ethanol at 95 mm Hg. In my book that's about an order of magnitude improved seperation efficiency. Cool. Very cool. 33.4 degrees C to be exact.

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by Adverse Effects » Fri May 22, 2009 8:44 am

schnell wrote:Most of you hope to get 95.6% someday. (If you're at sea level.) My vacuum stills can run 99.5% ethanol at 95 mm Hg. In my book that's about an order of magnitude improved seperation efficiency. Cool. Very cool. 33.4 degrees C to be exact.
ok so now you have braged about your still and what it can do

now show it to us
Some people say its "FREE" but i say "there ant no free lunch" you get what you pay/work for
help those that help them self first
25Lt old school SS keg as a pot with a prototype Ponu still head

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by FREAK! » Sat May 23, 2009 3:34 am

I am currently running through my 2nd spirit run with my new toy and I can’t pull those sort of numbers but the 95 mark is submerged at 20 degree C which makes me happy as Larry!!!
Last lot of pics attached, full spirit run set-up,

Thanks again to all of you that contribute to this forum, without this resource I would have spent much more money and ended up with inferior equipment without ever knowing what I was missing. Now I can pull hi quality booze without the headache’s
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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by LWTCS » Sun May 24, 2009 7:45 am

Freak,
That unit looks very fit. Good for you.

While becoming patient with your runs,, how long do your runs take?
Trample the injured and hurdle the dead.

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by FREAK! » Sun May 24, 2009 7:20 pm

I did a spirit run on the weekend, it took me 15 hours to run 25lt of 40% through the column. Very very happy with the results. :wink: :mrgreen:

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by Adverse Effects » Mon May 25, 2009 5:03 am

FREAK! wrote:I did a spirit run on the weekend, it took me 15 hours to run 25lt of 40% through the column. Very very happy with the results. :wink: :mrgreen:
15 hours to run 25 Lt?????

do you mean 1.5 hours?
Some people say its "FREE" but i say "there ant no free lunch" you get what you pay/work for
help those that help them self first
25Lt old school SS keg as a pot with a prototype Ponu still head

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by LWTCS » Mon May 25, 2009 10:02 am

Adverse Effects wrote:do you mean 1.5 hours?
Man I hope so.
Takes me an aggragate of 6 hours with my little 8 quart unit (from strip to spirit).

Whats your heating capacity?

Glad to here your liking yer likker though!
Trample the injured and hurdle the dead.

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by rad14701 » Mon May 25, 2009 11:20 am

Yeah, I'd be ale to run 25L in about 6 hours through my 8L boiler too, ending up with high ABV neutral...

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by FREAK! » Mon May 25, 2009 6:28 pm

I have a 1,300w immersed element. :?:

Everything I have read says to take it slow, so that’s what I have been doing, maybe too slow :shock: :oops: :lol: and I did go super slow at the begining trying some of the things Snuffy said

I did notice that even when I opened the product valve to flat out I was getting more products through and the abv% didn’t drop a bit. Witch made me think that the heating might be a bit light on

When I put the hydrometer in I just can’t seam to get the 95% mark to pop its head up from under the waterline, not that I am complaining

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by FREAK! » Tue May 26, 2009 3:03 pm

I just punched in all the numbers for my still on the parent site and I guess I can run the still a lot faster than I am.

1.225M packing height, SS pot scrubber as packing, 1300W power, Ø0.076M (3” diameter column)

Even with a RR of 1 she should pull over 95 and when I punch in a RR of 0.01 (basically taking everything that comes off the top of the packing) the purity only drops to 94.2 :lol:

I guess the next run I will crack the tack-off valve wide open after I have the heads out of the way and see what I get. Based on the amount of reflux I ran on the weekend I know the run time will be way less than half,

I have some birdwatchers in a settling tank, still another week away from running it and I can’t wait to try some of that compared to the turbos I have been using till now.

Can you taste the difference between the two even when you are taking product off at ABV 95 or more??? (watered back down for tasting of cource)

P.s. did I just ask another dumb question????? :oops: Guess I’ll know in a couple of weeks

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by Culpeper » Tue Jun 16, 2009 4:14 am

This is more of a question than a reply. I have decided to buil a colum still and after reading how they work wouldn't the first alchol (Methanol) also be recirculated back down the colum? Would discarding the first half pint of the run make any difference?

Culpeper

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by Ayay » Tue Jun 16, 2009 5:58 am

Culpeper, the foreshots (meths and other volatiles) will recirculate in the top bit of the column and won't get too far down. Running gently at the start will prevent the heads and hearts climbing up the column and mixing with the foreshots. Ideally the foreshots accumulate at the top and come out first, and then the heads follow doing the same and so on.

FREAK! It's like cooking; try it and see how it goes. Yes there are flavors from the brew in the 5% (some brews are more flavourfull than others), but worse are some tails in the 95%. There are many excellent descriptions here on how to do a perfect run but I'm still fluctuating between too fast and too slow and chasing the good cuts...the holy grail don't come easy :( .
cornflakes...stripped and refluxed

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Re: Newbee question Foreshot, Heads, Body or heart and tails

Post by Culpeper » Wed Jun 17, 2009 7:55 am

Howdy, Thanks for the reply. I figure that I will try to keep my heat below 180% as much as possible. Being this is a new thing for me Babysitting my new baby will be no problem as I plan on relaxing a tad while I am doing it..........The Wife doesn't retire for another 5 years.

Thanks, Culpeper

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