Lyne Arm Angle

[WooTeck]

yes there was a difference, i wouldnt say profound but noticeable and maybe 10 to 15 percent difference in ABV as well

interesting. id guess you would change the angle depeding on what you were running and what you were looking for. out of interest what angle did you choose more often? i like my spirts smooth for that im willing to sacrifice some flavour.
my plan is for the lyne arm to taper down from 52mm to 35mm to encorage some reflux.

I also did some more research googling the topic ... I found that a steep ascent going up say 45 degrees the alcoholic vapours have to fight their way uphill. Therefore, they cool down slowly resulting in a very smooth and high-proof distillate. Parallel outflow (horizontal lyne arm) the alcoholic vapours almost glide to the cooler. Therefore, they cool down moderately resulting in a rather smooth distillate. And last a steep descent (-) of the vapours the alcoholic vapours rapidly fall down to the cooler. Therefore, they cool down quickly resulting in a harsh but more low-proof distillate.

i read this in an old bushman thread. how dose it fit in with your exp?

[thecroweater]

if you strip then you can go steeper and it really depends on what you want, prolly 15 to 20 degrees i think

[Odin]

Lyne arm rising up gives you more passive reflux and up to 0.2 extra redistillation. When you distill slowly. Lyne arm going down ... 1 distillation only instead of 1.2.

Odin.

[myles]

It all depends on vapour speed and surface area.

There is one real easy way to know if it makes any difference. Simply measure the vapour temperature going into the arm and coming out. If they are the same then you know the arm is doing nothing.

Remember the purpose of the taper on the big onion stills? It is to maintain the vapour speed to compensate for the reduction in volume as the vapour cools.

[Fredistiller]

As I am rereading this very intresting topic, some questions came to my mind.

As you guys are using the word "taper". Do you actualy mean a conical shape? Of the lyne arm, the column, both? Couldn t get an answer in the glossary, nor from dr google. 8

Second, about the use of an common hobby sized horizontal lyne arm made from a pipe: When the first foreshots vapours takes off, and met the "cold" room temperature in the lyne arm, I assume they would condense...And stays there, because the arm is horizontal. Could it be an issue? Contaminate the vapors that follow? Or doesn t it work like that..

Thanks in advance!

[still_stirrin]

....As you guys are using the word "taper". Do you actualy mean a conical shape? Of the lyne arm, the column, both?

Yes, it is a conical taper, and yes, for both the tower and the lyne arm.

The taper compensates for the "cooling" vapors which, as they liberate some of its heat to the copper, cools and since density of a vapor is a function of the temperature, the density increases. When the density increases, the vapor velocity slows (constant mass flow, remember?). To compensate for that reduction in speed, the tube is tapered...so the velocity remains (more) constant.

If the vapor speed were to slow too much, it would indeed condense more which would affect the product throughput stability. So, like myles said, the taper is to maintain vapor velocity in both, the tower and the lyne arm.

...When the first foreshots vapours takes off, and met the "cold" room temperature in the lyne arm, I assume they would condense...And stays there, because the arm is horizontal. Could it be an issue? Contaminate the vapors that follow? Or doesn t it work like that...

This is somewhat explained in the answer above. The intent of the taper is to maintain vapor velocity (throughput). In a hobby sized pipe lyne arm, the velocity is typically much faster and as such, won't liberate excessive amouts of the heat it carries. So, it likely won't condense much, if at all.

OK, there may be a little condensation at the beginning before the still head is up to temperature (when the lyne is "cold", as you say). But that first bit, with the lowest boiling point and first to condense would be reheated by the vapors following it in the pipe such that it again vaporizes and travels on to the product condenser.

Will it "smear"....of course...a little. That is why the lines between foreshots and heads are "fuzzy". But by the time your still is actually producing, it will be up to temperature and you won't get appreciable condensation inside a horizontal lyne arm...unless it is excessively long (like more than 20 diameters). OK?
ss

[Fredistiller]

Yep that makes sense, thanks!!

[Alchemist75]

I guess I'm late to the conversation but I've fooled around with lyne arm angles, diameters, different materials and novel configurations. It definitely has an affect on how fast a run will progress.
A skinny, well insulated and downward angled design will run off the fastest and smear the most. A naked copper lyne arm of the same type will run slower. On the other extreme, a wider spiral riser lyne arm will run fast for a bit at full tilt but then it'll slow down and begin refluxing dragging the run on longer and flattening it all out. Run that same spiral at a lower energy input and you get a proof bump and less smearing. I operate a reasonably small set up but I actually have 4 separate possible lyne arm set ups that I can use for different purposes and they all behave very differently.

[Bushman]

I guess I'm late to the conversation but I've fooled around with lyne arm angles, diameters, different materials and novel configurations. It definitely has an affect on how fast a run will progress.
A skinny, well insulated and downward angled design will run off the fastest and smear the most. A naked copper lyne arm of the same type will run slower. On the other extreme, a wider spiral riser lyne arm will run fast for a bit at full tilt but then it'll slow down and begin refluxing dragging the run on longer and flattening it all out. Run that same spiral at a lower energy input and you get a proof bump and less smearing. I operate a reasonably small set up but I actually have 4 separate possible lyne arm set ups that I can use for different purposes and they all behave very differently.

Nice write up and confirms a lot of what you can find on line but in better detail. This post reminds me of a comment I made to a member earlier today that questioned another members comments because he probably hadn't tried it. If we read enough facts and members like you are willing to share their results we all benefit by the the experiments and tests done by others.

[Alchemist75]

Shape and size do matter even at the hobby level. The engineering of it all gets me hot and bothered.

[Kareltje]

Research and science is just a way of testing the answers to our questions. In scientific research the questions we as hobby distillers have, are answered by trained people with adequate equipment.
I remembered this http://whiskyscience.blogspot.nl/2014/10/copper.html" onclick="window.open(this.href);return false;" rel="nofollow
There is a figure in it about the angle of the lyne arm and its influence on taste.

[BugHunter]

If you have a 90 degree elbow at the top of your column, with a tri-clamp flange on it, then another 90 or 45 degree elbow to your arm, you can rotate it via the tri-clamp to get whatever angle you want to try out.

But judging from all the experienced folk who posted earlier, it doesn't sound like it makes much difference at small scale.

But the tri-clamp also makes it easier to clean and store the still in addition to giving the option of trying different angles.

[Alchemist75]

I think seeing the difference is a matter of going to pathological extremes in terms of shapes and configurations. The three basic angles may not produce major variation in terms of how a run progresses small scale but start fooling around with more outlandish stuff and then it becomes quite obvious.

[HDNB]

Shape and size do matter even at the hobby level. The engineering of it all gets me hot and bothered.

i think you hit on a key point earlier too...insulation makes a huge difference. I had insulation on top of my kettle that was contributing to smearing in a big way. Even without testing, i would believe your experience noted above about the same effect on insulated lyne arm.

[Garouda]

Shape and size do matter even at the hobby level. The engineering of it all gets me hot and bothered.

i think you hit on a key point earlier too...insulation makes a huge difference. I had insulation on top of my kettle that was contributing to smearing in a big way. Even without testing, i would believe your experience noted above about the same effect on insulated lyne arm.

I react a bit late, sorry.
Insulating your Lyne arm is nonsense, I'm afraid.
There's an important feature of all those pot stills: natural reflux.
Look at the shape of Charentais alembics, the bulb shape and size are designed to cause some reflux!
Also, in France Cognac can only be distilled from the end of fermentation till the last day of March, in cold places.
Do you notice any insulation on pot stills in Scotland?
See also: viewtopic.php?p=7767455#p7767455
The column is insulated, but not the Lyne arm...